SERIITR-252-2527 

UC Category: 59a 

DE85000540 

Analysis of Advanced Solar 

Hybrid ~esiccant Cooling 

Systems for Buildings 

Dennis Schlepp 

Kenneth ~chultz 

October 1984 

Prepared under Task No. 1600.23 

FTP No. 443 

Solar Energy Research Institute 

A Division of Midwest Research Institute 

161 7 Cole Boulevard 

Golden. Colorado 80401 

Prepared for the 

U.S. Department of Energy 

Contract No. DE-AC02-83CH10093 
Printed in the United States of America 

Available from: 

National Technical Informatior! Service 

U.S. Department of Commerce 

5285 Port Royal Road 

Springfield, VA 22161 

Price: 

Microfiche A01 

Printed Copy A04 

NOTICE 

This report was prepared as an account of work sponsored by the United States 

Government. Neither the United States nor the United States Department of Energy, 

nor any of their employees, nor any of their contractors, subcontractors, or their 

employees, makes any warranty, express or implied, or assumes any legal liability 

or responsibility for the accuracy, completeness or usefulness of any information, 

apparatus, product or process disclosed, or represents that its use would not 

infringe privately owned rights. 
PREFACE 

The objective for the Active Solar Heating and Cooling Program (U.S. Department of 

~nergy) is to develop the technology base to allow the private sector to produce efficient, economically competitive solar technology options for the marketplace. The program encompasses a balance of research on systems, components, and materials. The 

systems research directs the program through analysis of alternative, advanced concepts 

in heating and cooling. Additionally, research in systems reliability provides data on 

critical components and materials that affect long-term performance. The analysis and 

reliability programs are augmented by a laboratory and field-test program that develops 

data on experimental and state-of-the-art systems. These data identify design and operational problems and, thus, opportunities for research. 

The Component and Materials Program perf or ms research on advanced concepts that 

have been identified by systems analysis to offer promise of being competitive with conventional, nonrenewable energy sources. Key components, such as chillers, dehumidifiers, heat exchangers, and collectors, are evaluated through modeling and testing to 

improve energy delivery competitiveness. Advanced materials for these key components 

are evaluated or modified to provide improved performance and lower cost. 

This report presents an assessment of the energy savings possible from hybriddesiccantlvapor compression air conditioning systems and makes recommendations for 

continued research to develop high performance systems competitive with conventional 

cooling systems. 

This work was performed under Task 1600.23, Desiccant Cooling Research, during 

FY 1983 with funding provided by the U.S. Department of Energy's Office of Solar Heat 

Technologies. The authors thank Terry R. Penney of SERI and John W. Mitchell of the 

University of Wisconsin for their constructive reviews of this work. 

Dennis R. Schlepp 

Approved for 

SOLAR ENERGY RESEARCH INSTITUTE 

David Harley 

L.P @innon, Director 

So ar eat Research Division 
s:q19 TR-2527 - \=/ 

SUMMARY 

Objective 

This work assesses the energy savings possible from developing hybrid-desiccant/vaporcompression air conditioning systems and makes recommendations for further research 

into the concept. 

Discussion 

The idea of using desiccant dehumidifiers and vapor compression chillers to handle the 

latent and sensible loads of a building has been considered for years as technically possible but impractical with the state of the art in commercially available components. 

Recent advances in dehumidifier design for solar desiccant cooling systems have resulted 

in dehumidifier geometries with low-pressure drop and high efficiency in heat and mass 

transfer. These advances have prompted a new look at the hybrid concept. 

A study was undertaken to investigate a number of hybrid system configurations for residential and small commercial applications. Dehumidifiers, heat exchangers, indirect 

evaporative coolers, and vapor compression chillers were arranged into four configurations to cover a range of design possibilities. The systems were sized to handle a 10-kW 

(34011) air conditioning load at standard test conditions and then were analyzed for 

steady state performance over a wide range of ambient conditions. 

Conclusions and Recommendations 

All of the hybrid desiccant/vapor compression systems showed substantial savings in 

resource energy when compared to the best conventional systems with vapor compression. These savings ranged from 30% to 80%, depending on the operating conditions. 

The simplest system configuration, consisting of dehumidifier and vapor compression subsystems in series, was found to be the best overall performer. It is likely to be the least 

expensive to build and operate because of its simplicity. It is recommended that this 

configuration be investigated in seasonal simulation to evaluate its performance under 

transient load and operating conditions. Also, an experimental program to confirm the 

performance predicted in this study is recommended. 
TABLE OF CONTENTS 

1.0 Introduction ........................................................ 1 

2.0 Background ......................................................... 2 

2.1 System Configurations .......................................... 2 

2.2 Current Status ................................................. 4 

3.0 System Studies ...................................................... 7 

3.1 Candidate Systems ............................................. 7 

3.2 Analysis Tools ................................................. 8 

3.3 Control Methods ............................................... 11 

4.0 Results ............................................................ 14 

5.0 Conclusions and Recommendations .................................... 20 

6.0 References ......................................................... 21 

Appendix A Tabulated Study Results ........................................ 22 
Page 

2-1 Psychrometric Representation of Vapor Compression. Adiabatic 

Desiccant Dehumidifier . and Hybrid System Cooling Processes ............. 3 

2-2 Hybrid System Configuration for Supermarket Application ................. 4 

2-3 Liquid Desiccant Hybrid Cooling System ................................. 5 

2-4 Hybrid System for Small Office Building Applications ..................... 6 

3-1 System 1 Basic Hybrid ................................................ 8 

3-2 System 2 Hybrid with Heat Recovery ................................... 9 

3-3 System 3 Hybrid with Environmental Cooling ............................. 10 

3-4 System 4 Hybrid with Heat Receiver and Environmental Cooler ............. 11 

3-5 Range of Outdoor Conditions Encountered in Air.Conditioning .............. 13 

3-6 Outdoor Conditions for System Studies with State Points .................. 13 

4-1 Performance Map of Hybrid System 1 for Varying Outdoor Conditions ....... 15 

4-2 Performance Map of Hybrid System 2 for Varying Outdoor Conditions ....... 15 

4-3 Performance Map of Hybrid System 3 for Varying Outdoor Conditions ....... 16 

4-4 Performance Map of Hybrid System 4 for Varying Outdoor Conditions ....... 16 

4-5 System Performance Comparisons at Varying Dry Bulb Temperatures with 

HumidityRatio=0.012gH20/gair ..................................... 17 

4-6 System Performance Comparisons at Varying Dry Bulb Temperatures with 

Humidity Ratio = 0.01 4 g H20/g air ..................................... 17 

4-7 System Perf or mance Comparisons at Varying Dry Bulb Tempertures with 

Humidity Ratio = 0.016 g H20/g air ..................................... 18 

4-8 System Performance Comparisons with Varying Humidity Ratios Dry 0 Bulb Temperature = 33 C .............................................. 18 

4-9 System Performance Comparisons with Varying Humidity Ratios at Dry 

Bulb Temperature = 35'~ .............................................. 19 
Over the past several years, the 4U.s Department of Energy) Active Heating and Cooling 

Program has sponsored research Po develop competitive solar for cooling buildings. Part 

of this research program investigated combinations of dehumidification and evaporative 

cooling in solar-driven hybrid desiccant cooling systems. Desiccant cooling offers advantages as an option for building air conditioning, including use of low-temperature solar 

heat as the driving energy source, a broad range of residential and commercial building 

applications, and minimal initial cost with simple and inexpensive operation. 

The research has fwused on understanding and improving the heat and mass transfer 

characteristics of the dehumidifier component of desiccant cooling systems. In line with 

this effort the study evaluated the steady-state performance of hybrid desiccant/vapor 

compression systems, in a number of configurations, and compared the use of resource 

energy to that of conventional air-conditioning systems. This study will evaluate the 

potential for developing hybrid systems by using current knowledge in dehumidifier 

design and will point the way for further research, if warranted. 
SECTION !LO 

BACKGROUND 

In general, the best solutions to complex problems use appropriate technology that combines the features of several processes that meet the needs of the application. Combining vapor compression cooling and desiccant dehumidification to air-condition 

buildings is one example of this approach As outlined in an earlier report [ll, this combination uses the best features of each to meet the cooling requirement. 

Building loads have two components: sensible load and latent load The sensible load 

results from heat gain from high ambient air temperatures, solar and internal heat 

sources and requires lowering the temperature of the building air. Latent load involves 

lowering the humidity ratio of the air in the building and balancing the moisture gain 

from humid air entering the building and the gain from internal sources. 

Vapor compression systems are very good at providing sensible cooling. By having 

building air circulate over a chilled coil, the heat transfer from the air to the refrigerant 

effectively lowers the air temperature. However, when the vapor compression system 

has to handle the latent load as well, the only method available is to cool the air past its 

dew point and remove the excess moisture. To do so, the system must operate at a coil 

temperature of 2O-7'~ (35'-45'~), reducing the efficiency of the system. In addition, to 

maintain the building at a comfortable state, the air leaving the evaporator of the vaporcompression system must be reheated to the inlet state air temperature to maintain 

equilibrium in the building. Figure 2-la illustrates the processes involved on a 

psychrometric chart for the commercial application where reheat is involved. 

Desiccant cooling systems are very good at providing latent cooling by reducing the 

humidity ratio of building air. However, when the desiccant cooling system must handle 

the entire load, it overdries the process air so evaporative cooling can be used for the 

sensible cooling. A typical recirculation cycle for the desiccant cooling system is shown 

in Figure 2-1 b. 

Combining the ability of the desiccant dehumidifier to handle the latent load and the 

ability of the vapor compression subsystem to meet the sensible cooling load leads to a 

very efficient system. The dehumidifier subsystem needs to remove only enough 

moisture to satisfy the building's needs, thereby reducing the size of the dehumidifier and 

lowering the required regeneration temperature from the 70' to 80'~ needed by the 

desiccant cooling system to 50' to 60' for the hybrid system. The vapor compression 

subsystem needs only to cool the process air to the required supply temperature and not 

to the dew point temperature. As a result, the coil temperature can be raised from 7' to 

13O~, which increases the efficiency of the system. The combination can be further 

enhanced by using the heat rejected by the condenser of the vapor compression subsystem to help regenerate the desiccant in the dehumidifier. This synergistic action 

makes the hybrid system an energy efficient alternative to conventional building airconditioning systems. The processes of the hybrid system are shown on a psychrometric 

chart in Figure 2-lc. 

22 CURRENT STATUS 

The desiccant cooling systems discussed in Section 1.0 were proposed for residential 

applications; most of the hybrid systems proposed to date were for commercial 

applications. 

A cooperative effort among ThermoElectron, Gas Research Institute (GRI), and Jewell 

Supermarkets resulted in the installation of a hybrid system in a Jewell store 121. In a 

food store much of the sensible cooling is provided by the freezer and refrigeration 

cases. Additional dehumidification is often required, however. By using a desiccant 

dehumidifier to remove this moisture, the size of the vapor compression unit and the 

electrical power consumed can be reduced substantially. Additionally, the freezer and 

refrigeration cases can be operated more efficiently because less frost builds up. 

The simple configuration of the components shown in Figure 2-2 is used in the Jewell 

store. An adiabatic silica gel dehumidifier is used to dry ambient ventilation air. After 

passing through a heat exchanger to remove a portion of the heat of adsorption, the 

ventilated air is mixed with recirculated air and is sensibly cooled by the air conditioner 

to the required inlet temperature. Many problems were encountered during the first year 

of operation, yet results definitely indicated reduced energy use and economic viability. 

System performance and control remain to be optimized as the study continues. A 

similar system has been installed by Cargocaire in another supermarket [2l. 

Hybrid systems can also use liquid desiccant dehumidifiers. Gershon Meckler designed 

and installed the system shown in Figure 2-3 in a Veterans Administration Hospital [31. 

Outside ventilation air is dried by contact with a lithium chloride solution (with external 

cooling) and passed to the vapor compression unit. The solution is regenerated by 

heating it with solar energy or recovered waste heat and by subsequent contact with a 

Ventilation 

(3750 cfm) 

Heat 

E 

Desicca 

I+- 

Exhaust Outside 

air L4 

- 

Heat 0 

25,000 cfm rn 0 

d 6 Exhaust source - 

Heat 

exchanger Exfiltration 

---. - Supermarket (3750 cfm) 

2 3 - Transmission 

1) 

A 

--- Generation 

load 

Desiccant Sensible load - - 45 cooling 

coil 

4 5 

v 28.750 cfm) n 

Exhaust Outside 

air L4 Air 

conditioner 

Figure 2-2 Hybrid System Configuration for Supermarket Application 
Outside 

air 

6- 

m 

N 

Return air 0 

0 

Condenser 

7 Building 

I zones 

U 

Dehumidifier 

Indirect 

Evaporator - 

evaporative cooler 

Temperature 

Pigme 2-3. Liquid Desicemt HybFid Cooling System 

heated air stream. This hybrid system is expected to reduce building cooling costs by 

25%-50%. 

Current installations are in specialized applications because of unique cooling requirements and favorable economics. Researehers have analyzed a hybrid system for general 

applications in small office buildings C4,5,6:. The system has an adiabatic silica gel 

deaurnidifier and is shown in Figure 2-4. Room air (1) is mixed with the required amount 

of ventilation air (6) and dehumidified air (3). The air is then cooled (4) to near the 

ambient wet-bulb temperature (9) in an indirect evaporative cooler. This system 

removes much of the cooling load frs~n the vapor compression unit md is thermally 

rPfreeT1 cooling. The dehumidifier is regenerated by using combinations of solar energy, 
Cogenerator -. . . tlectrlc 

generator Electricity * fnr c\,ctem 8"s OJ.,, Internal combustion 

engine 

Recovered 

waste heat 

Solar/cogeneration storage tank 

Dehumidification 

system 

Exhaust air hr\+ ,.,fit C 

I w 

I,-, . 

i Runaround loop 

I -------- 

I 7 

L1~!Y!~~~~~~ 1 I r&n~e~~orl 1 ~1~111111 4 Return air IIUL-VVGL - - 

Heat recovery I 

- I I Heat 

coil Desiccant loop v! exchanger 

Outside air Supply dry-air 

hot-wet 

I 

I 

Desiccant 

dehumidifier 

- 

Cooling tower 

Figure 2-4. Hybrid System for Small Office Building Applications 

condenser waste heat, and auxiliary energy. Simulations of this hybrid system show that 

resource energy consumption can be reduced to 35%-55% of that used by a standard 

vapor compression system [5,61. The reduction depends on how much cooling can be 

obtained from the indirect evaporative cooler. The indirect evaporative cooler is very 

effective in dry climates, and energy savings can be large. 

The current supermarket installations do not include solar energy systems and the simulations of solid desiccant hybrid systems for general applications were not favorable to 

solar because most of the regeneration energy can be supplied by the condenser rejection 

heat. Systems using liquid desiccants are particularly suitable for solar regeneration. 

Many problems concerning system performance and control remain to be worked out; yet, 

it is vc~y c~rlcbo~rr.c~gir~y; t hr~t tllc. hybrid systems discussed here were designed and installed 

irl c-ornrncrc*inl scttings whcrc economics are a major factor. 
SECqlQW 3.8 

SYSTEM STUDIES 

%I CANDIDATE SYSTEMS 

In the performance characteristics of hybrid systems we found several choices 

of configuration Several components can be incorporated into the system to take 

advantage of waste-heat recovery and environmental cooling. Each of these components, 

such as heat exchangers and evaporative coolers, has advantages and disadvantages in 

cost and performance. 

To limit the breadth of the study, we made some assumptions about the type of hybrid 

system that could eventually be commercially competitive. First, the systems to be considered would be limited to residential and small commercial sizes of 10 to 80 kW (3 to 

25 tons) of cooling. Because the study uses laboratory-validated technology in solid 

desiccant dehumidifiers, the practical limit for single-unit systems is determined by the 

size of heat exchanger and dehumidifier wheels. To date, these units have been 

ccmstructed in sizes up to equivalent capacities of 80 kW. Second, the candidate systems 

must use standard industrial equipment for the vapor eompression subs stems and place B spper limits on evaporator a.nd condenser temperatures (1 3O@ and 60 C, respectively). 

Third, the systems considered should be simple. Although they will use energy-saving 

components as much as possible, only one level of heat recovery or environmental cooling 

will be used to minimize expense and ccnfrol. problems. System control and operating 

strategies are dkeussed in subsequent seetiofis. 

Using these basic assumptions, we chose four candidate systems for study: 

1, Basic hybrid desiccant/vapor compression system. As shown in Figure 3-1, the 

basic hybrid system combines desiccant dehumidifies and vapor compression 

subsystems in series, with the vapor compression condenser and auxiliary heat 

source providing regeneration heat for the dehumidifier. The psychrometric 

process for this candidate system is shown in Figure 3-1. 

2, Hybrid desiceant/vapor compression system with heat recovery. Figure 3-2 shows 

the second candidate systeh, which includes a heat exchanger to remove part of 

the heat of ~dsorption from the cooled air stream and to use if to preheat the 

aegerseraiion air stream. Piere 3-2 depicts the process path on a psychrometric 

chart. 

3, - Hybrid desiccant/vapor eornpressior? system with environmental cooling. An 

indl~ect evaporative cooler is used "i oool tl-i&~ocess 8ir stream to reduce the 

load OR the vapor compression evaporator, Ambient air is evapsratively cooled 

and then used in an air-to-aii. heat exchanger to lower the temperature of the 

essled air (Figure 3-31, The process p&k, irrcluding the evaporative cooling process (dashed line), is shown in Figure 3-3, 

4. Eiybvid d~slz.~:mt,,'x!apor eei~:pr~ssir,~~ sysi~rn with kmt recovery and environmnentaI ------ 7w- - -_^_------A_-- 

COO~YBZ;. <"iris @"3:$iguratxon uses I)~'ili the hhetif recovery wheel and indirect 

evaporetive cao'i~r lo paash Il,c cnergg LefPac~en@y as far as pcssible, The syste~ 

layokt is show11 in Figure 3-4 wnth the key prseess paths shown in Figure 3-4. 
I Exhaust Aux Vb 

I condr 

Dry bulb temperature (OC) 

k-.*r%Arnbient 

Figure 3-1. SJrstem 1 Basic Hybrid 

--DH-- 

We studied the design-point performance of each of these systems at a number of 

operating conditions. This approach identified possible high-performance configurations 

meriting further study regarding system integration, control, and operating economics. 

VC 

evapr 

3.2 ANALYSIS TOOLS 

1 2 

- 

To analyze the performance of the desiccant/vapor compression hybrid systems, we 

needed to define the analysis tools that could evaluate the steady-state performance of 

the components and systems. The key component, the dehumidifier, was modeled with 

laboratory validation by the DESSIM computer modeL Also, we used the MOSHMX 
Exhaust Aux VC 

Dry bulb temperature (OC) 

finite-difference model for heat and mass transfer tc independently verify test runs. We 

used both models to predict the behavior of tile paralle:-=pussage dehumidifier operating 

in a hybrid-desiccant/vapor-comp~;ession system, 

We :fiodeled tile perforrcmc-e of the vapo~-~~~~r,p~-esioiL ~t~b~~~fem using rr:anufacture~~'~ 

&;ia f rcsrrl Car: jer Corpor.aeioir, T!,ese daih prsi:&?ect! inforrrral iuim abcut tl?e relative 

zfficienq of the subsystem v-ith changes fr3 eva~~~afok an6 condenser temperatures, 

Bergt of Tvana Cc., (Slrnex.~mr-,:~, Tsx.) p$~~;Grti ~8?-$Ekk$e inf ~rrmaf i~i?s On "ihe !irriitEif iont 

of v~por-c.onzpr~ss:~?r~ eycies ir, hybrid-system o@erc%tnon. 
Exhaust 

condr 

Ambient 

Dry bulb temperature ("C) 

Figure 3-3. System 3 Hybrid with Environmental Cooling 

The heat recovery wheel used in two of the systems was modeled using information from 

tests with parallel-passage heat exchangers conducted at Monash University (Australia) 

[I. These heat exchangers have an effectivenesses of up to 93%. The data from these 

tests were used to determine the efficiency of the heat recovery at process conditions. 

Performance data on the indirect evaporative cooler were obtained from the work of 

Pescod 181 on a plate-type cross-flow heat exchanger in which one of the air streams is 

evaporatively cooled by spraying water in the channeL This arrangement provides a low 

sink temperature for the other air stream. An effectiveness of 90% was assumed in this 

analysis. More detailed analysis is required in subsequent studies. 
1 Exhaust Aux VC 

L~rnbient 

-- DH -- --HX-- 10 VC 

evapr 1 2 

b 

4 

- 

Dry bulb temperature ("C) 

Figure 3-4. System 4 Hybrid with Heat Receiver and Environmental Cooler 

3.3 CONTROL METHODS 

In modelling the hybrid systems it was necessary to define analysis state points, control 

strategies, and primary and secondary control parameters that the model would use to 

define state point conditions. 

The state points selected for the study are ranges of ambient conditions found in three 

cities representing different climates and cooling loads: Miami, Fla., Columbia, Mo., and 

Phoenix, Ariz. In a study of cooled-bed desiccant cooling cycles, Schultz [91 analyzed 

TMY (typical metorological year) profiles of hourly weather data to define regions of 

state conditions that could be encountered in these three citi-es (see Figure 3-5). From 
the regions defined in this study an analysis of the operation of the hybrid system showed 

that the region of temperature and humidity above the ARI design point would be critical 

to the analysis of the recirculation hybrid cycle, as shown in Figure 3-6. The points in 

this region are the ambient state points used for this study. 

To keep the systems as realistic as possible and to conform to industry practice, we made 

several assumptions about the control methods for the hybrid system. Each component 

requires an independent control subsystem since the system as a whole requires 

controls. For the desiccant dehumidifier the primary control is regeneration 

temperature. Since the dehumidifier will be called on to handle a variety of humidity 

levels, the regeneration temperature and, consequently, the capacity of the dehumidifier 

are most important to the hybrid system. Other parameters, such as the rotation speed 

and air flow rate, are less desirable as controls since they exhibit high input and output 

ratios on the control of outlet humidity ratio. The regeneration temperature of the air 

exiting the vapor compression condenser is limited to 58'~ (2'~ approach to the 60°C 

condenser operating temperature); so operating conditions requiring regeneration 

temperatures above 58'~ require auxiliary sources such as solar-generated thermal 

sources. 

Standard modulating methods control the vapor compression subsystem down to 50% of 

rated capacity, which is the practical limit for commercial systems. Operation below 

that point would be controlled by cycling or bypassing. 

Another industrial standard included in the simulation is to change the process flow rate 

as the load goes over the rated capacity of the unit. In this case the standard flow rate 

of 0.67 kg/s for 10 kW of cooling (1 200 scfm for 3 tons of cooling) is increased by 25% to 

0.84 kg/s (1500 scfm) to handle higher cooling loads. 

In all cases these assumptions ensure that system studies reflect performance in common 

HVAC installations. Flow rates, fan and duct sizes, and control methods are consistent 

with industrial practice. Also, the results can be extrapolated to auxiliary heat sources 

(such as waste heat) other than solar heat input. The system only recognizes that a heat 

source with a temperature of 60°C and above is present and able to supply sufficient 

heat for regeneration. 

SECTION 4.0 

The results of modeling the four hybrid systems are shown in Figures 4-1 through 4-4 as 

performance maps over the range of outdoor conditions discussed in Section 3.0. The 

graphs compare the power ratio of the energy consumption of the hybrid system with the 

energy consumption of the conventional competition, a heat pump with a cooling coefficient of 3.0 kW/kW. 

The performance maps show that, in general, the hybrid systems can save from 10% to 

90% of the electric consumption of a conventional system, depending on the operating 

conditions. The range of conditions near the ARI outdoor design condition (35O~, 

0.014 g/g) shows a plateau of performance values of 60% to 80% savings with the performance changing significantly as the conditions range to extremes of a higher ratio in 

humidity and temperature. Since the nature of this study was to define a system of given 

size and determine its performance over a range of conditions, one expects the system to 

perform best around its design point (the ARI state point) and to suffer in performance as 

the conditions were driven farther from design. However, the systems were able to save 

energy in almost every area of study. 

To make some qualitative judgments among the different system configurations, we 

compared the systems at certain points around the design point with varying temperatures at a fixed humidity ratio. These comparisons are shown in Figures 4-5 through 

4-9. As discussed earlier, System 1 is the basic hybrid configuration with the desiccant 

dehumidifier in series with the vapor compression system using condenser waste heat to 

regenerate the dehumidifier. System 2 adds a heat recovery wheel; System 3 includes an 

indirect evaporative cooler; and System 4 includes both the heat exchanger wheel and the 

indirect evaporative cooler. 

In comparing Systems 1 and 2 the effect of adding the heat exchanger is a benefit only at 

temperatures and humidities above the design point. Indeed, it is the same or lower in 

performance at all other points. This is because the temperature levels and differences 

present in the cycle are small and afford little benefit as preheat for the regeneration 

process. Therefore, adding a heat exchanger, critical to the desiccant cooling system, is 

not a benefit to the hybrid system and should not be part of a recirculation hybrid 

system. 

The comparison of Systems 1 and 3 is more interesting from a system design standpoint. 

In previous studies [4,5,61 the indirect evaporative cooler was found to be an essential 

part of a successful commercial hybrid system. In this study this conclusion is 

substantiated for conditions higher than the design point but is detrimental for conditions 

below the design point. In studying the details of the modeling results (see Appendix) the 

reason becomes clear. At temperatures and humidities above the design point the indirect evaporative cooler takes on a significant portion of the load that would normally be 

the job of the vapor compression system. This benefits the system performance as a 

whole. However, at temperatures and humidities below the design point the portion of 

the load handled by the indirect evaporative cooler reduces the load on the evaporator 

and, consequently, the amount of heat that the condenser can contribute to the 

regeneration of the desiccant dehumidifier. As a result, auxiliary energy makes up the 

difference, and the overall performance suffers. In general, using the indirect 

evaporative cooler at temperatures above design point makes sense because of the 

cooler's ability to aid the vapor compression subsystem. Using a variable effectiveness 

for the evaporative cooler by bypassing the process air control of the water supplied to 

the cooler could eliminate this problem. 




0.0 I I I J 

0 072 0.014 0.016 0.018 

Humidity ratio (g/g) 

ra Sys kt1 + Sys iY2 0 Sys #3 A Sys #4 

As ?raentics;ed earlier, using the Ireat exchanger had little benefit to the performance of 

the hybrid system, and, therefore, System 4 has exactly the same performance charszksristics as System 3. The combination of both energy-efficient components is not 

%&.-aihr&nteci since aU of "Lie inerease in perfor~arice is gained from the indirect evaporative eoofiei. c.1 System 3, 

The %<ey fir:djng of this analysis is that the hybrid system concept can save substantial 

;IST~~~UR~,S- ;S TPSC)U~~CC energy wlxn compared tsi the conventional system. When properly 

cz i:1-f'eP- tihe c-,szE,wratiori of System 3 ilisth e. variable effectjveness, indirect 

r,v~po:-~h'-~e e~ilqlfir" cost16 prove tc tcl a highly effieier~l air-esnditioning system for ~i"; . - eIr':?,aPe~t. m:~ :i?ad5, It ,-~i;ld we CE~~:~~.OSI~"L~ZE?~F~~ eso?ing when possible md still provide 

i"d baeiiilp .tor the converrh-ionaal vapor-eorrr.~rr.ssio~ subsysteira. The flaxibility ane! 

~fifci~ncs; OP ~tr~t: a system arc attrszrctive frcm s? operating standpointo 
CONCLUSIONS AND RECOMMENDATIONS 

This study shows that a packaged system with hybrid-desiccant/vapor-compression airconditioning can be a technically feasible alternative to conventional air-conditioning 

systems. Resource energy savings of 30%-80% can be realized over a wide range of 

operating conditions, when comparing steady-state performance of the hybrid with conventional systems. These results show promise for developing energy-efficient, airconditioning by extending existing state-of-the-art technology and warrant further 

research and analysis. 

Seasonal simulations of the hybrid systems should be undertaken to establish realistic 

energy savings when operating under variable loads and transient-operating conditions. 

These system studies should include the simple System 1 studied in this report, where the 

dehumidifier and vapor-compression subsystems are operated in series, and System 3, 

which incorporates the indirect evaporative cooler. This analysis must also include 

development and evaluation of control strategies for operating the various subsystems 

together. 

A laboratory experimental program to verify the analysis of the hybrid concept is 

required The effort should involve industrial participation from manufacturers of dehumidifiers and vapor-compression equipment. The project should confirm the accuracy of 

the design tools used in this study and should measure system performance under actual 

operating conditions. 
SECTION 6.0 

Schlepp, D., and K. Schultz, "High Performance Solar Desiccant Cooling Systems: 

Performance Evaluations and Research recommendation^,^^ SERIITR-252-2497, 

Golden, CO: Solar Energy Research Institute, (~ec.1 1983. 

Cohen, 8, A. Levine, and R. Arora, Thermo Electron Corp. "Field Development of a 

Desiccant-Based Space-Conditioning System for Supermarket Applications," 

TE4308-42-83, Chicago, IL: Gas Research Institute, (~eb.) 1983. 

"It's Not the Heat, Itrs the Humidity," The Energy Daily, VoL 10, No. 123, 

2 July 1982. 

Sheridan, J., and J. W. Mitchell, "Hybrid Solar Desiccant Cooling Systems," - Proceedings of the Annual Meeting of AS/ISES, Houston, TX, 1982. 

Howe, R. R., W. A. Beckman, and J. W. Mitchell, vTCommercial Applications for 

Solar ~ybrid Desiccant systems," Proceedings of the Annual ~eeting of ASES, 

Minneapolis, MN, 1983. 

Howe, R. R., W. A. Beckman, and J. W. Mitchell, "Factors Influencing the Performance of Commercial Hybrid Desiccant Air Conditioning Systems," presented at the 

Intersociety Energy Conversion Engineering Conference, Orlando, FL, (Aug.) 1983. 

Maclaine-cross, I. L., "A Theory of Combined Heat and Mass Transfer in Regenerators," PhD. Thesis, Clayton, Victoria, Australia: Department of Mechanical Engineering, Monash University, 1974. 

Pescod, D., "Unit Air Cooler Using Plastic Heat Exchanger with Evaporatively 

Cooled plate^,^^ Australian Refrigeration, Air Conditioning, and Heating, Vol. 22, 

No. 9, pp. 22-26, 1968. 

Schultz, K. L., "The Performance of Desiccant Gehumidifier Air Conditioning Systems Using Cooled Dehumidifiers," M.S. Thesis, Madison: Solar Energy Laboratory, 

University of Wisconsin, May 1983. 

APPENDIX A 

TABULATED STUDY RESULTS 

HYBRID SYSTEM ANALYSIS - System 1 ........................................... 

Ambient T (C 1 27.0 29.0 31.0 

Ambient W (g/g) 0.0120 0.0120 0.0120 

Ambient H (J/g) 57.77 59.83 61.89 

Room T ( C 1 26.7 26.7 26.7 

Room W 19/91 0.0110 0.01 10 0.0110 

Room H (J/gl 54.92 54.92 54.92 

Bldg Load (kW) 1.92 3.29 4.67 

Flow Rate (kg/s) 0.67 0.67 0.67 

dlddT 0.00333 0.00043 0.00023 

Supply T (CI 26.4 24.4 22.4 

Supply W (g/g) 0.0100 0.0100 0.0100 

SupplyH (J/g) 52.06 50.00 47.94 

DH Out T (C) 30.0 30.0 30.0 

DH Out W (g/gl 0.0100 0.0100 0.0100 

DHOutH (J/g) 513. 79 55.78 35.78 

Regen T (C) 34.2 34.2 34.2 

Regen W (g/g) 0.0120 0.0120 0.0120 

Regen H IJ/g) 65.19 63.19 65.19 

VCE R (kW) 2.50 3.88 5.26 

Lead Ratio 0.24 0.37 0.50 

VC COB (kW/kW) 3.90 3.77 3.63 

VC Work (kW) 8.64 1.03 1.45 

VCC R (kW) 3.14 4.91 6.70 

Poss VCC T (C) 31.6 36.1 40.7 

Max VCC T (C) 31.6 36.1 40.7 

VCC W fg/g) 0.0120 Q.0120 0.0120 

VCC H (J/g) 62.46 67.16 71.90 

Aux Q I kW) 1.82 0.00 0.00 

Total Q (kW) 2.46 1.03 1.4% 

ConvLewT (C) 14.2 14.2 

Conv Low W (gig) 0.0100 0.0100 

Conv Low H fJ/g) 39.51 39. 50 

Conv Revap (kW1 10.32 10.33 

Load Ratio 0.98 0.98 

VC COP (kW/kW) 3.48 3.40 

Conv Wcomp (kW) 2.97 3.04 

Conv Acond (kW) 13.29 13.37 

Reheat A IkW) 8.41 7.03 

total A (kW1 11.37 10.07 

Pwr Ratio 0.22 0.10 0.17 
HYBRID SYSTEM ANALYSIS - System 1 

Ambient T [ C 1 

Ambient W (g/g) 

Ambient H (J/g) 

Room T (C 1 

Room W (g/g) 

Room H (J/g) 

Bldg Load tkW) 

Flow Rate (kg/s) 

dWdT 

Supply T (C) 

Supply W (g/g) 

SupplyH IJ/g) 

DH Out T (C) 

DH Out W (g/g) 

DH Out H (J/g) 

Regen T (C) 

Regcn W (gfg) 

Regsn H (J/g) 

VCE Q (kW) 

Load Ratio 

VC COP (kW/kW) 

VC Work (kW) 

VCC P (kW) 

Poss VCC T (C) 

Max VCC T (C) 

VCC W (g/g) 

VCC H (J/g) 

Aux Q (kW) 

Total Q (kW) 

Conv Low T (C) 

Conv Low W (g/g) 

Conv Low H (J/g) 

Conv Qavap (kW1 

Load Ratio 

VC COP (kW/kW) 

Conv Wcomp (kW) 

Conv Bcond (kW) 

Reheat Q (kW) 

Total Q (kW) 

Pwr Ratio 
HYBRID SYSTEM ANALYSIS - System 1 ----------------------I---I--uAmbient T (C) 31.0 33.0 

Ambient W (g/g) 0.0140 0.0140 

Ambient H (J/g) 67,01. 69.07 

Room T (C 26.7 26.7 

Raom W (g/g) 0.0110 0.01.10 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 8.10 9.49 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.00070 0.00048 

Supply I- I C) 22.4 20.4 

Supply W (g/g) 0.0080 0.0080 

Supply H (J/g9 42.82 40.76 

DH Out T (C) 36.9 36.9 

DH Out W (g/g) 0.0080 0.0080 

DHOutH (Jig) 57.65 57.65 

Regen T (C) 49.4 49.4 

Regen W (g/g) 0.0140 0.0140 

Regen # (J/gl 86.02 86.02 

VCE Q ( kWl 9. 94 11.32 

Load Ratio 0.94 1.07 

VC COP (kW/kkBf 3.38 5.22 

VC Work (kW1 2.94 3.51 

VCC L2 IkW) 12.818 14.83 

Boss VCC T (Cl 49.6 54.4 

Max VCC T (C 1 49. & 54.4 

VCC W (g/g) 0.0140 0.0140 

VC6 H (J/g) 8b. 23 91.21 

Aux Q (kW) 0.00 0.00 

Total Q (klrd) 2.94 3.531 

Conv bow T (Cl 

Conv Low W (g/g) 

Conv Law H IJfg) 

Conv Qevap (kW) 

Load Ratio 

VC COP (kW/kW) 

Conv Wcomp (kW1 

Conv Qcand (kW1 

Reheat G! (kW1 

Total Q (kW) 

Pwr Ratio 0.22 0.29 
HYBRID SYSTEM ANALYSIS - System 1 ................................... 

Ambient T (C) 27.0 29.0 

Ambient W (g/g) 0.0160 0.0160 

Ambient H (J/g) 67.98 70.05 

Room T (Cl 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 8.75 10.14 

Flow Rate (kg/sl 0.67 0.67 

dWdT 0.01667 0.00217 

Supply T (C ) 26.4 24.4 

SupplyW (g/g) 0.0060 0.0060 

Supply H (J/gl 41.83 39.76 

DH Out T (C 1 44.7 44.7 

DH Out W (g/g) 0.0060 0.0060 

DHOutH (J/q) 60.47 60.44 

Regan T (C 1 68.5 68.5 

Regen W (g/g) 0.0160 0.0160 

Reqen H (J/gl 111.04 111.04 

VCE Q IkW) 12.49 13.e35 

Load Ratio 1.18 1.31 

VC COP (kW/kW) 3.39 3.22 

VC Work (kW) 3.69 4.30 

VCC Q (kW) 16.17 18.16 

Pass VCC T (C) 50.3 55.1 

Max VCC T (C) 50.3 55.1 

VCC W (g/gl 0.0160 0.0160 

VCC H (J/gl 92.12 97.16 

Aux Q (kWl 12.68 9.30 

Total Q (kW1 16.37 13.61 

Conv Low T (C) 6.5 6.5 

Conv Low W fg/g) 0.0060 0.0060 

Conv Low H (J/gl 21.58 21.52 

Conv Qevap (kW1 22.33 22.37 

Load Ratio 2.12 2.12 

VC COP (kW/kW) 2.67 2.58 

Conv Wcomp (kWl 8.38 8.66 

Conv Bcond (kW) 30.71 31.04 

Reheat Q (kW1 13.57 12.22 

Total Q (kW) 21.95 20.88 

Pwr Ratio 0.75 0.65 
HYBRID SYSTEM 4NfXYSIS - System 1 .................................... 

Ambient i (62) 37.0 27.0 

Amb~ent W rg/g) 0.0160 O.0180 

Ambient H tJlg) 78. 35 93,OB 

Room 7 (C3 26.7 26.7 

Room W (gEq1 @.0$10 0.0116 

Room H f=J/g) 54.92 94.92 

~ldg Load (kw) 15.78 12. as 

Flow Rate (kg151 0.84 0,84 

dWdP 0.00049 0.02333 

SUPP~Y 7- [ 6) 18.4 26.5 

suppayd tg/gf 0,~090 0.0034 

Supply H (J/g) 36.13 40.36 

DH Dut 7" (C 1 58.9 49.9 

DH Out W (g/g) 0.0078 P.0054 

DHOutH UdJg) 56.84 58.10 

Regen T IC) 54.6 67.5 

Regen kJ (g/g) 0.01&0 0.0180 

Regen H (J/g) 96.61 119.26 

VCE Q (klni) 1%. 33 14.636, 

Laad Rwtica $,44 1.41 

VC COP (klr-J/"kWl 2. $7 3.25 

VC Work SkW) la, 50 4.58 

VCC # akW) 23.89 19.45 

PBSS vce T rcl 71.3 94.9 

Max VCC T I I= SB. 0 54,9 

VGC W (g/q) 6.0160 0.Q18U 

VCI: H (J/g) 100. f4 102.11 

Aux R (kW) 0.00 €I. 80 

Total L! f kid) 6.50 13.40 

LonvLowT (C) 

Canv Low W (g/91 

Canv Low H (J/g) 

Cnnv Qevap (kW) 

Load Wati a 

VC 681; (kW/kW) 

Canv Wcomp (kW) 

Conv Bcond (kWf 

Reheat 61 (kW) 

Tatal Q (kg) 

Fwr Ratio 0.33 0.40 
HYBRID SYSTEM ANALYSIS - System 1 ................................... 

hmbient T (C) 35.0 27.0 

Ambient W (g/gf 0.0160 0.0200 

hmbient H (J/g) 81.41 78.18 

Room T (C 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 17.75 15.59 

Flow Rate (kg/s) 0.64 0.84 

dWdT 0.00084 0.03000 

Supply T (C 20.0 26.5 

SupplyW (g/g) 0.0054 0.0038 

SupplyH (J/g) 33.70 36.28 

DH Out T (C) 43.9 50.4 

DH Out W Ig/g) 0.0054 0.0098 

DHOutH (J/g) 58.00 60.56 

Regen T (C 67.5 86.6 

Regen W (g/g) 0.0160 0.0200 

Regen H (J/g) 115.26 140.50 

VCE Q (kW) 20.35 20.34 

Load Ratio 1.93 1.93 

VC COP (kW/kW) 2.53 2.85 

VC Work (kW) 8.04 7.13 

VCC Q (kW) 28.39 27.4'7 

Pass VCC T (C) 75.7 66.2 

Max VCC T 1 C) 58.0 58.0 

VCC W (g/g) 0.0160 0.0200 

VCC H (J/g) 105.36 110.57 

Aux G! (kW) 6.63 20.05 

Total Q (kW) 14.68 27.18 

ConvLowT IC) 4.7 

Conv Lew W tg/g) 0.0054 

Conv bow H (J/g) 1E3.20 

Conv Qevap f kW 1 30.75 

Load Ratio 2.92 

VC COP (kW/kW) 1.71 

Conv Wcomp (kW1 16.00 

Conv Bcond (kW> 48.75 

Reheat G! IkW) 12.99 

Total G! (kW> 30.98 

Pwr Ratio 0.47 0.62 
HYBRID SYSTEM ANALYSIS - System 2 ................................... 

Ambient T (C) 27. 0 29.0 

Ambient W (g/g1 0.0120 0.0120 

Ambient H tJ/g) 57.77 59.89 

Room T (C) 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 1.92 3.29 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.00333 0.00043 

Supply T tC) 26.4 24.4 

Supply W (g/g) 0.0100 0.0100 

Supply H (J/g) 52.06 50.00 

DH Out T (C) 30.0 30.0 

DH Out W (g/g) 0.0100 0.0100 

DHOutH (J/g) 55.79 55.78 

HX La T (C) 28.0 30.0 

HX La W Ig/g) 0.0100 0.0100 

HX La H tJ/g) 53.70 55.74 

Regen T (C) 34.2 34.2 

Hsgen W Ig/g) 0.0120 0.0120 

Regen W (Jig) 65.19 65. 19 

HX Hi T IC) 29.0 29. 0 

HX Hi W (g/g) 0.0120 0.0120 

HX Hi H (J/g) 59.87 59.87 

VCE 42 (kW) 1.10 3.85 

Load Ratio 0.10 0.36 

VC COP fkW/kW) 3.95 3.77 

VC Work (kW) 0.28 1.02 

VCC GI (kW) 1.38 4.87 

Poss VCC T (C) 29.0 3b. 1 

Max VCI: T (C 1 29.0 36.1 

uec w (g/g) 0.0120 0.0120 

VCC H (J/g) 59.83 67.10 

Aux Q (kW) 3.59 0.00 

Total Q (kW) 3.87 1.02 

Conv Low T IC) 14.2 14.2 

Conv Low W (g/gl 0.0100 0.0108 

Conv Law H IJ/g) 39.51 39.50 

Gunv Bevap ! kW) 10.32 10.33 

Load Ratio 0.98 0.98 

VC COP (kW/kW) 13.48 5.40 

Cenv Weomp (kWI 2.97 9.04 

Cnnr Qcond fkWl 13.29 13.37 

Reheat W ikW: 8.41 7.03 

'Total R (kW) 11.57 10.07 

Pwi- Rat ia i:~ . 3 46.18 (a. 39 
HYBRID SYSTEM ANALYSIS - System 2 ................................... 

Ambient T (C 37.0 39.0 

Ambient W (g/g) 0.0120 0.0120 

Ambient H (J/g) 68.07 70.13 

Room T (C) 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 8.81 10.19 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.00010 0.00008 

Supply T (Cl 16.4 14.4 

Supply W (g/g) 0.0100 0.0100 

Supply H (J/g) 41.76 39.70 

DH Out T (C 30.0 30.0 

DH Out W (g/g) 0.0100 0.0100 

DHOutH (J/g) 55.78 55.78 

HX Lo T (C) 30.0 30.0 

HX LO W (g/g) 0.0100 0.0100 

HX Lo H (J/g) 55.78 55.78 

Ragen T (C 1 34.2 34.2 

Regen W (g/g) 0.0120 0.0120 

Regen H (J/g) 65.19 65.19 

HX Hi T (C) 37.0 39.0 

HX Hi W (g/g) 0.0120 0.0120 

HX Hi H (J/g) 68.07 70.13 

VCE Q (kW) 9.39 10.77 

Load Ratio 0.89 1.02 

VC COP (kW/kW) 3.17 3.01 

VC Work (kW) 2.96 3.58 

VCC Q (kWl 12.35 14.35 

Poss VCC T (C) 54.9 59.8 

Max VCC T (C 54.9 58.0 

VCC W (g/g) 0.0120 0.0120 

VCC H (J/g) 86.50 89.70 

Aux R (kW) 0.00 0.00 

Total 61 (kWl 2.96 3.56 

Conv Low T (C) 14.2 14.2 

Cmnv Low W (g/g) 0.0100 0.0100 

Conv Low H (J/g) 39.50 39.50 

Cenv Bevap (kW) 10.33 10.33 

Load Ratia 0.96 0.98 

VC COP (kW/kWl 3.08 3.00 

Conv Wcomp (kW) 3.36 3.45 

Conv Qcund (kWf 13.69 13.78 

Reheat R (kW) 1.52 0.14 

Total R (kW) 4.87 3.59 

Pwr Ratio 0.61 1.00 0.84 0.91 
HYBRID SYSTEM ANALYSIS - System 2 ................................... 

Ambient T I C 1 31,0 33.0 

Ambient W (g/gf 0.0140 0.0140 

Ambient H (J/g) 67.01 69.07 

Room T (C 1 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 8.10 9.49 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.00070 0.00848 

Supply T (C) 22.4 20.4 

Supply W (g/g) 0.0080 0.0080 

SupplyH (J/g) 42.82 40.96 

DH Out T (C) 36.9 36.9 

DH Out W (g/g) 0.0080 0.0080 

DHOutH (J/g) 57.65 57.65 

HX Lo T (C 32.0 34.0 

HX Lo 19 (g/g) 0.0080 0.0080 

HX Lo H IJ/g) 52.65 34.68 

Hegrn T (C) 49.4 49.4 

Regen kl (g/g) 0.0140 0.0140 

Regen H (J/g) €315.02 86.02 

HX Hi T IC) 35.9 35.9 

HX Hi W (g/g) 0.0140 0.0140 

HX Hi H IJ/g) 72.07 72.07 

VCE A ikW) 6.58 9.33 

Load Ratia 0.62 0.88 

VC COP (kW/kW) 3.56 3.34 

VC Work (kW) 1-85 2. 80 

VCC Q IkW) 8.43 12.13 

Pass VCC T (C) 43.2 50.5 

Max VCC T (C 43.2 50.3 

VCC W (g/q) 0,0140 8.0140 

VCC H (J/gl 79.59 87.18 

Aux A (kkJ) 4.31 0.00 

Total A (kW) 6.16 2.80 

Conv LQW T (C) 10.7 

Conv Low W (q/g) 8.0080 

Conv bcw H (J/gb 30.93 

Gonv Qevap (kW1 1b.07 

Load Ratio 1.52 

VC CUP (kWikW) 2. $5 

Canv Wcnntp (kW1 5.44 

Canv Qca~d EkM) 2% - 52 

Reiteat G IkW) '6.47 

rat31 a t k~j 13.42 
HYBRID SYSTEM ANALYSIS - System 2 ................................... 

Ambient T (C) 27.0 29.0 

Ambient W (g/g) 0.0160 0.0160 

Ambient H (J/g) 67.98 70.05 

Room T (C) 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/q) 54.92 54.92 

Bldg Load (kW) 8.75 10.14 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.01667 0.00217 

Supply -I- (C) 26.4 24.4 

Supply W (g/g) 0.0060 0.0060 

SupplyH (J/g) 41.83 39.76 

DH Out T (C) 44.7 44.7 

DH Out W (g/q) 0.0060 0.0060 

DHOutH (J/g) 60.47 60.44 

HX Lo T (C 28.0 30.0 

HX Lo W (g/g) 0.0060 0.0060 

HX Lo H (J/q) 43.46 45.47 

Regen T (C) b8.5 68.5 

Regen W (g/g) 0.0160 0.0160 

Regen H (J/g) 111.04 111.04 

HX Hi T (C) 43.7 43.7 

HX Hi W (g/g) 0.0160 0.0160 

HX Hi H (J/g) 85.30 85.30 

VCE Q (kW) 1.09 3.83 

Load Ratio 0.10 0.36 

VC COP (kW/kW) 3.95 3.77 

VC Work (kW) 0.28 1.01 

VCC Q (kW) 1.37 4.84 

Poss VCC T (C) 29.0 36.0 

Max VCC T (C 29.0 36.0 

VCC Ld (gig) 0.0160 0.0160 

VCC H (Jig) 70.02 77.28 

Aux 13 (kW) 27.48 22.62 

Total a (kW) 27.76 23.64 

Conv Low T (6) 6.3 

ConvLow W (gig) 0.0060 

Cenv Low H (J/g) 21.5B 

Conv Qcvap (kW1 22.33 

Load Ratio 2.12 

VC COB (kW/kW) 2.67 

Conv Weomp (kt41 8.38 

Conv Rcond (kW) 30.71 

Reheat G! tkW) 13.57 

Total Q (kW) Zl.c%Z 

Pwr Ratie 1.26 1.15 
HYBRID SYSTEM ANALYSIS - System 2 

Ambient T (C 37.0 

Ambient W (g/g) 0.0160 

Ambient H (J/g) 78.35 

Room T (C) 26.7 

Room W (g/g) 0.0110 

Room H (J/g) 54.92 

Bldg Load (kW) 15.70 

Flow Rate (kg/s) 0.84 

dWdT 0.00049 

Supply 1 (C) 18.4 

Supply W (g/g) 0.0070 

SupplyH (J/g) 36.15 

DH Out T (C) 38.7 

DH Out W (g/g) 0.0070 

DHOutH (J/g) 56.84 

HX Lo T (C) 38.0 

HX Lo W (g/g) 0.0070 

HX Lo H (J/g) 56.15 

Regen T (C) 54.6 

Regen W (g/g) 0.0160 

Regen H (J/g) 96.61 

HX Hi T (C 37.7 

HX Hi W (g/g) 0.0160 

HX Hi H [J/g) 79.05 

VCE G! (kW) 16.75 

Load Ratio 1.59 

VC COP ikW/kW) 2.71 

VC Work IkW) 6.19 

VCC R (kW) 22.94 

Poss VCC T (C) 70.0 

Max VCC T (C) 58.0 

VCC W (g/g) 0.0160 

VCC H (J/g) 100.14 

Aux R (kW) 0.00 

Total Q (kW) 6.19 

ConvLowT (C) 8.7 

Conv Low W (g/g) 0.0070 

Conv Low H (J/g) 26.30 

Conv Qevap (kW) 23.97 

Load Ratio 2.27 

VC COP (kW/kW) 2.14 

Conv Wcomp (kW) 11.18 

Conv Qcond (kW) 35.14 

Reheat R (kW) 8.25 

Total Q (kW) 19.43 

Pwr Ratio 0.32 
HYBRID SYSTEM ANALYSIS - System 2 

Ambient T (C) 35.0 

Ambient W (g/g) 0.0180 

Ambient H (J/g) 81.41 

Room T (C) 26.7 

Room W (g/g) 0.0110 

Room H (J/g) 54.92 

Bldg Load (kW) 17.75 

Flow Rate (kg/s) 0.84 

dWdT 0.00084 

Supply T (C) 20.0 

SupplyW (g/g) 0.0054 

SupplyH (J/g) 33.70 

DH Out T (C) 43.9 

DHOutW (g/g) 0.0054 

DHOutH (J/g) 58.00 

HX Lo T (C) 36.0 

HX Lo W (g/g) 0.0054 

HX Lo H (J/g) 49.97 

Regen T (C 67.5 

Regen W tg/g) 0.0180 

Regen H IJ/gl 115.26 

HX Hi T (C) 42.9 

HX Hi W (g/g) 0.0180 

HX Hi H (J/g) 89.63 

VCE G! (kW) 13.62 

Load Ratio 1.29 

VC COP (kW/kW) 2.99 

VC Work (kW) 4.55 

VCC Q I kW) 18.17 

Pass VCC T (C) 61.0 

Max VCC T (C) 58.0 

VCC W (g/g) 0.0180 

VCC H (J/g) 105.36 

Aux R (kW) 6.63 

Total Q (kW) 11.18 

Conv Low T (Cf 4.7 

ConvLow W (g/g) 0.0054 

Conv Low H tJ/g) 18.20 

Conv Revap (kW) 30.75 

Load Ratio 2.92 

VC COP (kW/kW) 1.71 

Conv Wcamp (kW) 18.00 

Conv Qcond (kW) 48.75 

Reheat (5 IkW) 12.99 

Total Q (kW) 30.98 

Pwr Ratio 0.36 
HYBRID SYSTEM ANALYSIS - Systrm 3 

Ambient T tC) 27.0 

Ambient W tg/g) 0.0120 

Ambient H (J/g) 57.77 

Room T (C) 26.7 

Room W (g/g) 6.0110 

Room H (J/g) 54.92 

Bldg Load (kW) 1.92 

Flow Rate (kg/=) 0.67 

dWdT 0.00333 

Supply T (C) 26.4 

Supply W (g/g) 0.0100 

Supply H (J/g) 52.06 

DH Out T (C 1 30.0 

DH Out W (g/g) 0.0100 

DHOutH IJ/g) 55.79 

XEC Lo T (C 26.4 

IEC Lo W (q/g) 0.0100 

IECLoH (Jig) 52.06 

Regen T (C) 34.2 

Regen W (g/g) 0.0120 

Regan H (J/g) 65.19 

XEC Hi T (C) 20.8 

IEC Hi W 1g/g) 0.0145 

IECHiH (J/g) 57.74 

VCE G! (kW) 0.00 

Load Ratio 0.00 

VC COP (kW/kbl) 3.98 

VC Work (kW) 0.00 

VCC Q (kW) 0.00 

Pass VCC I (C) 27.0 

Max VCC T (C 27.0 

VCC W (g/g) 0.0120 

VCC H iJ/g) 57.77 

Aux G! (kW1 4.97 

Total &L (kW) 4.97 

ConvLowT (C) 14.2 

ConvLow W (g/g) 0.0100 

Conv Law H IJ/gl 39.51 

Conv Qevap (kW) 10.32 

Load Ratio 0.98 

VC COP (kW/kW> 3.48 

Conv Wcomp IkW) 2.97 

Canv Qcond (kW1 13.29 

Reheat: GI (kW) 8.41 

Total Q (kW) 11.37 

Pwr Ratio 0.44 
HYBRID SYSTEM ANALYSIS - System 3 --------I-------------------------- 

Ambient T C C ) 37.0 39.0 

Ambient W (g/g) 0.0120 0.0120 

Ambient H (J/g) 68.07 70.13 

Room T C C 1 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 8.81 10.19 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.00010 0.00008 

Supply T (C) 16.4 14.4 

Supply W (g/g) 0.0100 0.0100 

SupplyH (J/g) 41.76 39.70 

DH Out T (C) 30.0 30.0 

DH Out W (g/g) 0.0100 0.0100 

DHOutH (J/g) 55.78 55.78 

IEC Lo T (C) 25.3 25.8 

IEC Lo W (g/g) 0.0100 0.0100 

IECLoH (J/q) 50.92 51.43 

Regen T (C) 34.2 34.2 

Regen W (g/g) 0.0120 0.0120 

Reqen H (J/g) 65.19 65.19 

IEC Hi T (C 24.3 24.8 

IEC Hi W (g/g) 0.0171 0.0175 

IECHiH (J/g) 67.98 69.52 

VCE G! (kW) 5.14 7.86 

Load Ratio 0.58 0.75 

VC COP (kW/kW) 3.35 3.18 

VC Work (kW) 1.83 2.47 

VCC Q (kW) 7.97 10.33 

Pass VCC T (6) 48.6 54.0 

Max VCC T (C) 48.6 54.0 

VCC W (g/q) 0.0120 0.0120 

VCC H (J/gl 79.96 85.55 

Aux Q (kW) 0.00 0.00 

Total 8 (kW) 1.83 2.47 

Conv Low Y (C) 

Conv Low W (g/g) 

Conv Low H (J/g) 

Conv Qevap (kW) 

Load Ratio 

VC COP (kW/kW) 

Conv Wcomp (kW) 

Conv Bcand (kW) 

Reheat Q (kW) 

Total Q (kW) 

Pwr Ratio 0.38 0.69 
WVBHID SYSTEM ANALYSIS - System 3 

Amhimnt T (C) 31.0 

fimbirnt W (g/gl 0.0140 

fimhient H (J/g) 67.01 

Ncmm T (C 26.7 

Room W (g/g) 0.0110 

Ftnom H (J/g) 54.92 

Oldg Load (kW) 8.10 

t low Rate (kg/s) 0.67 

tlWdT 0.00070 

Uupply T (Cf 22.4 

Uupply W (g/g) 0.0080 

Llrrpply H (J/g) 42.82 

OH Out T (C 36.9 

DH Out W (g/g) 0.0080 

UHOutH (Jig) 57.65 

ItC Lo T (C) 24.3 

IECLoW (g/g) 0.0060 

IEC Lo ti (J/gl 44.78 

Rwgmn T (C) 49.4 

limgmn W (g/g) 0.0140 

Rmgmn H (J/g) 66.02 

IEC Hi T (C) 23.3 

IEC Hi W (g/g) 0.0172 

IECHiH (J/gl 67.20 

VCE Q (kW) 1.31 

Load Ratio 0.12 

VC COP (kW/kW) 3.78 

VC Work (kW) 0.35 

VCC Q (kW) 1.66 

PorsVCCT (Cl 33.4 

Max VCC T (C 33.4 

VCC W (g/g) 0.0140 

VCC H (J/g) 69.49 

Rux GI (kW) 11.08 

Total Q (kW) 11.43 

[:onvLowT (C) 

l:onv Low W (g/g) 

I:onv Low H (J/g) 

Conv Qevap (kW) 

I oad Ratio 

VC COP (kW/kW) 

[:onv Wcomp (kW) 

Conv Qcond (kW) 

Hmheat CJ (kW) 

Total GI (kW) 

Pwr Ratio 0.85 
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HYBRID SYSTEM ANALYSIS - System 3 ................................... 

Ambient T (C) 37.0 27.0 

Ambient W (g/gl 0.0160 0.0180 

Ambient H (J/g) 78.35 73.08 

Room T (C) 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldq Load (kW) 15.70 12.17 

Flow Rate (kg/s) 0.84 0.84 

dWdT 0.00049 0.02333 

Supply T (C) 18.4 26.5 

SupplyW (g/g) 0.0070 0.0054 

Supply H (J/g) 36.15 40.36 

DH Out T (C 38.7 43.9 

DHOutW (g/g) 0.0070 0.0054 

DHOutH (J/g) 56.84 58.10 

IEC Lo T (C) 27.8 26.5 

IECLoW (g/g) 0.0070 0.0054 

IEC Lo H (J/g) 45.75 40.36 

Regen T (C) 54.6 67.5 

Regen W (q/g) 0.0160 0.0180 

Regcn H (J/g) 96.61 115.26 

IEC Hi T (C 1 26.8 24.2 

IEC Hi W (g/g) 0.0205 0.0190 

IECHiH (J/ql 79-23 72.72 

VCE Q (kW) 8.04 0.00 

Lord Ratio 0.7$ 0.00 

VC COP (kW/kWl 3.25 3.98 

VC Work (kW) 2.47 0.00 

VCC Q (kW) 10.51 0.00 

Poss VCC T (C) 52.1 27.0 

Max VCC T (C) 52.1 27.0 

VCC W (g/g) 0.0160 0.0180 

VCC H (J/g) 94.03 73.08 

Aux G! (kW) 1.72 28.26 

Total Q (kW) 4.20 28.26 

Conv Low T (C) 8.7 

Conv Low W (g/g) 0.0070 

Conv Low H (J/g) 26.30 

Conv Qevap (kW) 23.97 

Load Ratio 2.27 

VC COP (kW/kW) 2.14 

Conv Wcomp (kW1 11.18 

Conv Qcond (kW) 35.14 

Reheat R (kW) 8.25 

Total G! (kW) 19.43 
HYBRID SYSTEM ANALYSIS - System 3 ................................... 

Ambient T (C) 35.0 27.0 

Ambient W (g/g) 0.0180 0.0200 

Rmbient H (J/g) 81.41 78.18 

Room T (C) 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 17.75 15.59 

Flow Rate (kg/s) 0.84 0.84 

dWdT 0.00084 0.03000 

Supply T (C) 20.0 26.5 

SupplyW (g/g) 0.0054 0.0038 

SupplyH (J/g) 33.70 36.28 

DH Out T i C 1 43.9 50.4 

DH Out W (g/g) 0.0054 0.0038 

DHOutH (J/g) 58.00 60.56 

IEC Lo T (C) 28.0 26. !5 

IEC Lo W (g/g) 0.0034 0.0038 

IECLoH (J/g) 41.83 36.32 

Regen T (C 1 67.5 86.6 

Regen W (g/g) 0.0180 0.0200 

Regen H (J/g) 115.26 140.50 

IEC Hi T (C 27.0 25.5 

IEC Hi W (g/g) 0.0214 0.0205 

IECHiH (J/g) 81.76 77.89 

VCE P (kW) 6.81 0.03 

Load Ratio 0.65 .OO 

VC COP (kW/kW) 3.39 3.98 

VC Work (kW) 2.01 0.01 

VCC Q (kW1 8.91 0.04 

Pose VCC T (CT 47.6 27.1 

Max VCC T (C) 47.6 27.1 

VCC W (g/g) 0.0180 0.0200 

VCC H (J/g) 94.56 78.25 

Aux Q (kW) 13.87 41.71 

Total Q (kW) 15.87 41.72 

ConvLowT (C) 

Canv Low W (g/g) 

Conv Low H (J/q) 

Conv Qevap (kW) 

Load Ratio 

VC COP (kWlkW) 

Conv Wcomp (kW) 

Conv Qcsnd (kW) 

Reheat Q (kW) 

Total Q (kW) 

Pwr Ratio 0.51 0.96 
HYBRID SYSTEM ANALYSIS - System 4 

Cambient T h C 1 27.0 29.0 

Ambient W fg/g) 6.0120 0.0120 

fimbient H (J/g) 57.77 59.83 

Room T (C) 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H (J/q) 54.92 54.92 

Bldg Load (kW) 1.92 3.29 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.00333 0.00043 

Supply T (C) 26.4 24.4 

Supply W Ig/g) 0.0100 0.0100 

SupplyH IJ/g) 52. 06 50.00 

DH Out T IC 1 30.0 30.0 

DH Out W Ig/g) 0.0100 0.0100 

DHOutH (J/g) 55.79 55.78 

HX Lo T I C) 28.0 30.0 

HX Lo W (g/g) 0.0100 0.0100 

HX La H IJ/g) 53.70 55.74 

IEC Lo T (C 26.4 24.4 

IEC LO W (g/g) 0.0100 0.0100 

IEC Lo H (J/g) 52.06 50.00 

Regen T (C 1 34.2 34.2 

Regen W (g/g) 0.0120 0.0120 

Ragen H (J/g) 65.19 6s. 19 

HX Hi T (C) 29.0 29.0 

HX Hi T (g/g) 0.0120 0.0126 

HX Hi T (J/g) 59.87 59.87 

IEC Hi T (C t 20.8 21.5 

IEC Hi W (g/g) 0.0145 0.0653 

IECHiH IJ/g) 57.74 60.50 

VCE Q (kW) 0.00 0.00 

Laad Ratio 0.00 0.00 

VC COP (kW/kW) 3.98 3.90 

VC Work (kW) 0.00 0.00 

VCC Q (kW) 0. 00 0.00 

Poss VCC 9 (C) 27.0 29.0 

Max VCC T I C 1 27.0 29.0 

VCC W (g/g) 0.0120 0.0120 

VCC H (J/g) 57.77 59.83 

Aux GI (kW) 4.97 3.59 

Total 61 (kW) 4.97 3.59 

Conv Low T (C) 14.2 14.2 

Conv Law bd (q/g) 0.0100 0.0160 

Conv Law H fJ/g) 39.51 39.30 

Conv Revap t kW) 10.32 18.33 

Load Ratin 0.98 0.98 

VC COP IkW/kW) 3.48 3.40 

Esnv Wcsmp (kW) 2.99 5.04 

Gonv Rsmd (kW) 13.29 i3.37 

Rehercat G.2 IkW) E3, 411 7.03 

Total Q IkMZ 1%. 37 18,017 

PWF- Rat lo %a, rb4 6,3b 
HYBRID SYSTEM ANALYSIS - System 4 ................................... 

Ambient T (C) 37.0 59.0 

Ambient W (g/q) 0.0120 0.0120 

Ambient H (J/q) 68.07 70.13 

Room T (C) 26.7 26.7 

Room W (q/q) 0.0110 0.0110 

Room H (J/q) 54.92 54.92 

Bldq Load (kW) 8.81 10.19 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.00010 0.00008 

Supply T (C I 16.4 14.4 

Supply W (q/g) 0.0100 0.0100 

SupplyH (J/g) 41.76 39.70 

DH Out T (C) 30. 0 30.0 

DH Out W (g/q) 0.0100 0.0100 

DH Out H (J/g) 55.78 55.78 

HX Lo T (C 38.0 40.0 

HX Lo W (g/g) 0.0100 0.0100 

HX Lo H (J/g) 63.95 66.00 

IEC Lo T (C) 25.3 25.8 

IEC Lo W (g/g) 0.0100 0.0100 

IECLoH (Jig) 50.92 51.43 

Regen T (C ) 34.2 34.2 

Rergen W (g/g) 0.0120 0.0120 

Regen H (J/g) 65.19 65.19 

HX Hi T (C) 29.0 29.0 

HX Hi T (g/g) 0.0120 0.0120 

HX Hi T (J/g) 59.87 59.67 

IEC Hi T (C 24.3 24.8 

IECHi W (q/g) 0.0171 0.0175 

IECHiH (J/q) 67.98 69.52 

VCE Q (kW) 6.14 7.86 

Load Ratio 0.58 0.75 

vc COP (kW/kW) 3.35 3-18 

VC Work (kW) 1.83 2,47 

VCC Q (kW) 7.97 10.33 

Poms VCC T (C) 48.6 54.0 

Max VCC T (C) 48.6 54.0 

VCC W (q/q) 0.0120 0.0120 

VCC H (J/q) 79.96 85.55; 

Aux Q (kW) 0.00 0. OQ 

Total Q (kW) 1.85 2.47 

Conv Low T (Cl 14.2 14.2 

Conv Low W (q/q) 0.0100 0.0100 

Conv Low H (31q) 39. 50 39.50 

Conv Qevap (kW) 10.33 10.33 

Load Ratio 0.98 0.98 

VC COP (kW/kW) 3.08 3.00 

Conv Wcomp (kW) 3.36 3.45 

Conv Qcond (kW) 13.69 13.78 

Reheat A (kW) 1.52 0.14 

Total Q (kW) 4.87 3.59 

Pwr Ratio 0.38 0.69 

HYBRID SYSTEM ANALYSIS - System 4 --------------------e-------------- 

Ambient T (C 27.0 29.0 

Ambient W (g/g) 0.0160 0.0160 

Ambient H (J/g) 67.98 70.05 

Room T (C) 26.7 26.7 

Room W (g/g) 0.0110 0.0110 

Room H I J/g) 54.92 54.92 

Bldg Load (kW1 8.75 10.14 

Flow Rate (kg/s) 0.67 0.67 

dWdT 0.01667 0.00217 

Supply T (Cl 26.4 24.4 

Supply W (g/g) 0.0060 0.0060 

Supply H (J/g) 41.83 39.76 

DH Out T (C 1 44.7 44.7 

DHOutW (g/g) 0.0060 0.0060 

DH Out H (J/g) 60.47 60.44 

HX Lo T (C) 28.0 30.0 

HX Lo W (g/g) 0.0060 0.0060 

HX LO H (J/g) 43.46 49.47 

IEC Lo T (C) 26.4 25.0 

IECLo W (g/g) 0.0060 0.0060 

IECLoH (J/g) 41.83 40.38 

Regen T (C) 68.5 68.5 

Regen W (g/q) 0.0160 0.0160 

Regen H (J/gf 111.04 111.04 

HX Hi T (C) 43.7 43.7 

HX Hi T 19/91 0.0160 0.0160 

HX Hi T (J/g) 85.30 8s. 30 

IEC Hi T (C 23.3 24.0 

IEC Hi W (g/g) 0.0177 Q.0182 

IECHiH IJ/g) 68.47 70.47 

VCE P (kW) 0.00 0.42 

Load Ratio 0.00 0.04 

VC COP (kW/kW) 3.98 3.89 

VC Work (kW1 6.00 0.11 

VCC P (kW) 0.00 0. 52 

Poss VCC T (Cl 27.0 29.8 

Max VCC T (C) 27.0 29.8 

VCC b4 (g/g) 0.0160 0.0160 

VCC H (J/g) 67.98 70.83 

Aux 61 (kW) 28.85 26.94 

Total G1 (kW) 28.85 27.05 

Conv Low T (C) 

Conv Low W (g/g) 

Conv Low H (J/g) 

Conv G!evap (kW) 

Lend Ratio 

VC COP (kW/kW) 

Conv Wcomp (kW) 

Conv G!cond (kW) 

Reheat GI (kW) 

Total P (kW) 

Pwr Ratio 1.31 1,30 
HYBRID SYSTEM ANALYSIS - System 4 -------------I--------------------- 

Ambient f (C ) 37.0 27.0 

Ambient W (g/g) 0.0160 0.0180 

Ambient H fJ/g) 76.35 73.08 

Room T (C) 26.7 26.7 

Room W (gig) 0.0110 0.0110 

Room H (J/g) 54.92 54.92 

Bldg Load (kW) 15.70 12.17 

Flow Rate (kg/s) 0.84 0.84 

dWdT 0.00049 0. 02333 

Supply T (C) 18.4 26.5 

SupplyW (g/g) 0.0070 0.0054 

Supply H (J/g) 36. IS 40. 36 

DH Out T (C) 38.7 43.9 

DH Out W (g/g) 0.0070 0.0054 

DHOutH (J/g) 56.64 58.10 

HX Lo T (C) 38.0 28.0 

HX Lo W (g/g) 0.0070 0.0054 

HX Lo H IJ/g) 56.15 41.93 

IEC Lo T (C) 27.6 26.5 

IECLoW (g/g) 0.0070 0.0054 

IECLoH (J/g) 45.75 40.36 

Regen T (C) 54.6 67.5 

Regrn W (g/g) 0.0160 0.0180 

Regen H (J/g) 96.61 113.26 

HX Hi T (C 37.7 42.9 

HX Hi T (g/g) 0.0160 0.0180 

HX Hi T (J/g) 79.05 69.63 

IEC Hi T (C) 26.8 24.2 

IEC Hi W (g/g) 0.0205 0.0190 

IEC Hi H (Jig) 79.25 72.72 

VCE O (kW) 8.04 0. 00 

Load Ratio 0.76 . 0.00 

VC COP (kW/kW) 3.25 3.96 

VC Work (kW) 2.47 0. 00 

VCC G! (kW) 10.51 0.00 

Poss VCC T IC) 52.1 27.0 

Max VCC T (C) 52.1 27.0 

VCC W (g/g) 0.0160 0.0180 

VCC H (J/g) 94.03 73.08 

CIUX R (kW) 1.72 28.26 

Total P (kW) 4.20 28.26 

ConvLawT 

Conv Low W (g/g) 

Conv Low H (Jig) 

Conv Oevap (kW) 

Load Ratio 

VC COP (kW/kW) 

Conv Wcomp IkW) 

Conv Ocond (kW) 

Reheat P (kW) 

Total Q (kW) 

Pwr Ratio 0.22 0.85 
HYBRID SYSTEM QNALYSIS - System 4 ................................... 

Ambient T (C) 35.0 27.0 

Ambient W (g/g) 0.0180 0.0200 

Qmbient H (J/g) 81.41 78.18 

Room T (Cl 26.7 26.7 

Room W (g/g) 0.0110 0.011O 

Room H tJ/g) 54.92 34.92 

Bldg Load (kW) 17.75 15.59 

Flow Rate (kg/s) 0.84 0.84 

dWdT 0.00084 0.03000 

Supply T (C) 20. 0 26.5 

SupplyW (g/g) 0.0054 0.0038 

SupplyH tJ/g) 33.70 36.28 

DH Out T (C 43.9 50.4 

DH Out W (g/g) 0.0054 0.0038 

DHOutH (J/g) 58.00 60.56 

HX Lo T (C) 36.0 28.0 

HX Lo !A (g/g) 0.0054 0.0038 

HX Lo H (J/g) 49.97 37.84 

IEC Lo T (C) 28.0 26.5 

IECLoW 19/91 0.0054 0.0038 

IECLoH (J/g) 41.83 36.32 

Regen T (C) 67.5 96.6 

Regen W (g/g) 0.0180 0.0200 

Regen H (J/g) 115.26 140.50 

HX Hi T (C 42.9 49.4 

HX Hi T (g/g) 0.0180 0.0200 

HX Hi T iJ/g) 89.63 101.58 

IEC Hi T (Cl 27.0 25.5 

IEC Hi W (g/g) 0.0214 0.0205 

IECHiH (J/g) 81.76 77.99 

VCE Q (kW) 6.81 0.03 

Load Ratio 0.65 . 00 

VC COP (kW/kW) 3.39 3.98 

VC Work (kW) 2.01 0.01 

VCC P (kW) 8.81 0.04 

Poss VCC T (C) 47.6 27.1 

Max VCC T (C) 47.6 27.1 

VCC W (g/g) 0.0180 0.0200 

VCC H (J/g) 94.56 78.25 

Aux G! (kW) 13.87 41.71 

Total P (kW) 15.87 41.72 

Conv Low T (C) 

Conv Low W (g/g) 

Conv Low H (J/g) 

Conv Pevap (kW) 

Load Ratio 

VC COP (kW/kW) 

Conv Wcomp (kW) 

Conv Qcond (kW) 

Reheat GI (kW) 

Total GI (kW) 

Pwr Ratio 0.51 0.96 
SELECTED DISTRIBUTION LIST 

Kennard I,. Bowlen 

Cargocaire Engineering Corp. 

79 Monroe St. 

Amesbury, MA 01913 

Jim Coellner, Director R&E 

American Solar King Corp. 

700 Loop 340 South 

Waco, TX 76710 

Barry Cohen 

Thermal Products Division 

Thermo Electron Corporation 

45 First Avenue 

Waltham, MA 02154 

Dr. Kirk Collier 

Collier Engineering 

Route 2, Box 240 

Cave Creek, AZ 85331 

Mr. Keith Davidson 

Gas Research Institute 

8600 West Bryn Mawr Avenue 

Chicago, IL 60631 

Mr. Robert Dikkers 

National Bureau of Standards 

Technology B-148 

Washington, D.C. 20585 

A. Hunter Fanney 

Bldg. 226, Room B310 

National Bureau of Standards 

Washington, D.C. 20234 

Mr. Anthony Fraioli 

Argonne National Laboratory 

9700 South Cass Avenue 

Argonne, IL 60439 

Mr. John Goldsmith 

Route CE-3 11, Room 5H065 

U.S. Department of Energy 

1 000 Independence Ave., S. W. 

Washington, D.C. 20585 

R. Harkins 

ASES 

2030 17th St. 

Boulder, CO 80302 

Richard B. Hayter 

Engineering Extension 

Ward Hall, Kansas State University 

Manhattan, KS 66506 

Wm. C. Irwin 

Energy Demonstration & Technology 

Division 

Electrical Utilization Group 

Tennessee Valley Authority 

1850 CUBB-C 

Chattanooga, TN 37401 

Ralph Johnson 

NAHB Research Foundation, Inc. 

3720 T St., N.W. 

Washington, D.C. 20007 

Robert Jones 

Los Alamos National Lab 

P.O. Box 1663 

Mail Stop H577 

Los Alamos, NM 87545 

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Overview of Advanced Hybrid Desiccant Cooling 

Sys tern 

Page I SERI/TR-252-2527 I 

4. Title and Subtrtle 

October 1984 

5. Publication Date 

I 

7. Author(s) 1 8. Performfng Organization Rept. No. 

1 

12. Sponsoring Organ~zation Name and Address 13. Type of Report & Period Covered 

Dennis Schl ep~, genneth Schul tz 

9 Perform~ng Organization Name and Address 

Solar Energy Research Institute 

1617 Cole Boulevard 

Go1 den, Colorado 80401 

Technical Reuort 

14. 

10. Pro]ecVTask/Work Un~t No 

1600.23 

11 Contract (c) or Grant (G) NO. 

(C) 

I 

15. Supplementary Notes 

16. Abstract (Limit: 200 words) 

This report describes an assessment of the energy savings possible from developing hybrid desiccant/vapor-compression air conditioning systems. Recent 

advances in dehumidifier design for solar desiccant cooling systems have resultec 

in a dehumidifier with a low pressure drop and high efficiency in heat and mass 

transfer. A recent study on hybrid desiccant/vapor compression systems showed 

a 30%-80% savings in resource energy when compared with the best conventional 

systems with vapor compression. A system consisting of a dehumidifier with 

vapor compression subsystems in series was found to be the simplest and best 

overall performer. 

I 17. Document Analysis 

a. Descriptors Dehumidifiers ; Dehumidification ; Desiccants ; Evaporative Cooling ; 

I eat Exchangers ; Hybrid Systems ; Solar Cooling Systems ; Vapor 

compression-~efri~eration cycle 

b. Identifiers/Open-Ended Terms 

I c. UC Categories 

18. Availability Statement 

National Technical Information Service 

U.S. Department of Commerce 

5285 Port Royal Road 

Springfield, Virginia 22161 

19. No. of Pages 

5 6 

20. Price 

I I 

Form No. 0069 (3-25-82)