Conference Paper

NREL/CP-550-48383

August 2010

Advanced Dehumidification 

Analysis on Building America 

Homes Using EnergyPlus

Preprint

Xia Fang, Jon Winkler, and Dane Christensen

National Renewable Energy Laboratory

Presented at International High Performance Buildings Conference 

at Purdue

West Lafayette, Indiana

July 12–15, 2010
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1

Advanced Dehumidification Analysis on Building America Homes Using EnergyPlus1

Xia FANG*,1, Jon WINKLER*,2, Dane CHRISTENSEN3

Electricity, Resources & Building Systems Integration

National Renewable Energy Laboratory

1617 Cole Blvd. MS 5202

Golden, CO, USA 80401

303.384.7440 main

303.384.7540 fax

1

Xia.Fang@nrel.gov 2

Jon.Winkler@nrel.gov

3

Dane.Christensen@nrel.gov

* Corresponding Author

ABSTRACT

With the Building America (BA) program advancing to the 50% source energy savings level, it is becoming a high 

priority to properly model whole house moisture loads and operation of humidity control equipment. In a 50% 

savings home, space sensible cooling load is significantly reduced by high-performance envelopes, EnergyStar 

appliances, and efficient lighting. Conventional air-conditioning equipment is unlikely to maintain healthy space 

relative humidity during key periods of the year. In addition, with the significant reduction of the other space energy 

consumption, dehumidification equipment energy consumption becomes a bigger portion of whole house energy 

consumption.

A parametric study was conducted using EnergyPlus version 4.0 to analyze the impact of various dehumidification 

equipment and control strategies on a typical mid-1990’s reference home, a 2006 IECC home, and a highperformance home in a hot humid climate. Space relative humidity, thermal comfort, and whole house energy 

consumption were analyzed. The study was compared with past published modeling results (Henderson et al., 2008).

The results confirmed that supplemental dehumidification must be provided in a high-performance home in order to 

maintain space conditions below 60% relative humidity. A detailed analysis was conducted to examine indoor 

relative humidity excursions; specifically the number of excursions, average excursion length, and maximum 

excursion length. Recommendations were made on dehumidification options in high-performance homes.

1. INTRODUCTION

As the Building America (BA) program begins constructing homes that achieve 50% and greater source energy 

savings, modeling whole house moisture loads and operation of humidity control equipment properly has become a 

high priority. In a 50% savings home, space sensible cooling load is significantly reduced due to high-performance 

 1 Employees of the Alliance for Sustainable Energy, LLC, under Contract No. DE-AC36-08GO28308 with the U.S. Dept. of 

Energy have authored this work. The United States Government retains and the publisher, by accepting the article for 

publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to 

publish or reproduce the published form of this work, or allow others to do so, for United States Government purposes. This work 

was supported by the U.S. Department of Energy under Contract No. DE-AC36-08-GO28308 with the National Renewable 

Energy Laboratory.
2

envelopes, EnergyStar appliances, and efficient lighting. Conventional air-conditioning equipment is unlikely to 

maintain healthy space relative humidity (RH) during key periods of the year in humid climates since a majority of 

the time when the space relative humidity goes out of control is when the air-conditioner (A/C) does not run or runs 

at part load conditions. Because of the significant reduction in whole house energy consumption, dehumidification 

equipment energy use becomes a bigger portion of whole house energy consumption. Improved simulation of these 

systems’ interactions will enable optimization of a home’s features for durability, healthy indoor air quality, 

minimizing energy use and system cost, and other similar goals.

A parametric study was conducted using EnergyPlus version 4.0 (DOE, 2009) to analyze the impact of various 

dehumidification equipment and control strategies on a high-performance home at the 50% source energy savings 

level. A typical mid-1990’s reference home and 2006 code compliant home serve as basis for comparison. The 

analysis uses the city of Houston, which represents the hot-humid climate region. Living space relative humidity,

thermal comfort, and whole house energy consumption were examined. 

The paper presents analysis results examining relative humidity “excursions,” defined as a unique event of indoor 

relative humidity above a threshold. For each mechanical system in this study, the number of excursions, average 

excursion length, and maximum excursion length were recorded. Mold growth can begin during an excursion above 

70% RH in as little as 24 hours, under ideal conditions. “If the space relative humidity consistently stays above 70% 

for an extended period of time, mold will almost certainly grow” (Epidemiology, 2003). One 24-hour long RH 

excursion promotes much more mold growth than twenty-four intermittent 1-hour long RH excursions, and 

therefore, does much more harm to the house. Mold is known to reduce the home’s durability and result in degraded 

indoor air quality, so significant excursions must be controlled to ensure a healthy home.

Past studies (Henderson et al., 2008) were conducted using TRNSYS to analyze space air-conditioning equipment 

with and without humidity control strategies. The study used the TRNSYS 16 multi-zone type 56 building model to 

analyze either natural infiltration with Sherman-Grimsrud model or constant mechanical ventilation as prescribed by 

ASHRAE 62.2-2004. This paper examines combined infiltration and mechanical ventilation effects with both 

balanced and unbalanced mechanical ventilation systems in EnergyPlus. The infiltration model from Walker and 

Wilson (1998) was used. The Walker and Wilson infiltration model was developed specifically for residential 

buildings and includes more detailed coefficients compared to the Sherman-Grimsrud method. In addition, a

sensitivity analysis was conducted to examine the range of house leakage areas vs. space relative humidity.

2. MODELING APPROACH AND ASSUMPTIONS

2.1 Descriptions of Homes

Three homes were used in the analysis: a typical mid-1990’s reference home which was adopted from the BA 

Benchmark Home (Hendron and Engebrecht, 2010), a 2006 International Energy Conservation Code (IECC) house 

(ICC, 2006), and a high-performance home - 50% source energy savings level whole house technology package 

developed using a cost and performance analysis (Anderson and Roberts, 2008). The geometry from Anderson and 

Roberts (2008) was used for all three homes. The house used in the analysis was a two-story, three-bedroom, 2500 

square foot, slab-on-grade home. The house was assumed to be west facing with an 18% window-to-floor area ratio. 

The parameters that varied between the three homes that have the largest impact on the living space humidity levels 

are shown in Table 1.

The heating and cooling set points were established by BA benchmark definition at 71°F (21.67°C) for heating and 

76°F (24.4°C) for cooling constant 24/7 year round and a constant relative humidity (RH) set point of 55%, when 

applicable. Based on the BA benchmark definition the house had 3 occupants that followed an occupancy schedule 

such that the house had fewer occupants during the daytime hours. The average daily internal moisture loads listed 

in Table 1 were generated using the benchmark prescribed load profiles for water use fixtures (such as the shower, 

bath, and sinks) and appliances (such as the clothes washer and dishwasher). The difference in the internal moisture 

loads among the three homes is due to EnergyStar appliances. Remaining schedules and assumptions are consistent 

among the three homes and can be found in the BA benchmark definition. 
3

Table 1: Features of the three homes used in the analysis

Reference Home IECC 2006 Home

(Climate Region 2)

High-performance

Home

Wall Assembly 2x4, 16” on center, 

R-11 cavity

2x4, 16” on center, 

R-13 cavity

2x6, 24” on center, 

R-21 cavity

Ceiling Assembly R-20 assembly R-30 assembly R-30 assembly

Windows U-value = 1.0

SHGC = 0.79

U-value = 0.75

SHGC = 0.40

U-value = 0.35

SHGC = 0.26

Specific Leakage Area (SLA) 0.00057 0.00036 0.00015

Duct Location Vented Attic Vented Attic Conditioned Space

Duct Leakage

R-5

10% Supply Leakage

5% Return Leakage

R-8

10% Supply Leakage

5% Return Leakage

N/A

Average Daily Internal

Moisture Loads 8.6 kg/day 8.3 kg/day 6.7 kg/day

Heat Pump Rating SEER 10, HSPF 7.2 SEER 13, HSPF 8.1 SEER 15, HSPF 8.8

Mechanical Ventilation Spot Vents Only 100% ASHRAE 62.2 100% ASHRAE 62.2

2.2 Dehumidification Parametric Case Descriptions

Case 0 represents the high-performance home equipped only with a typical air-conditioner for space conditioning as 

described in Table 1. The cooling set point is constant at 76°F (24.4°C).

2.2.1 Thermostat Reset (Case 1): Despite the air-conditioning system maintaining a well controlled cooling set point 

of 76°F (24.44°C) there are hours where space relative humidity reaches high levels, resulting in reduced thermal 

comfort. Under these circumstances, it is fairly common for occupants to dial down the thermostat set point a couple

of degrees, causing the air conditioner to run which reduces indoor temperature and humidity based on the 

equipment’s Sensible Heat Ratio (SHR). This comfort control practice brings down the space relative humidity and 

the quantity of hours exceeding 60% relative humidity. The model set a home Predicted Mean Vote (PMV) limit of 

±0.5 when the occupants are expected to actively change the thermostat (7:00am – 7:00pm) and a relaxed PMV limit 

of ± 1.0 during the rest of the day.

2.2.2 A/C with Energy Recovery Ventilator (ERV) (Case 2): In the summer time, an ERV cools and dries the hot 

and humid outside ventilation air by exchanging heat and moisture into the (conditioned) house exhaust air. Pretreating the ventilation air permits downsizing the A/C cooling capacity. Using an ERV for mechanical ventilation 

will reduce the space humidity level and the amount of hours of RH exceeding 60%. The modeled ERV is a static 

enthalpy heat exchanger with an average winter/summer effectiveness of 75% / 60%.

2.2.3 Heat Exchanger Assisted A/C (Case 3): A heat-exchanger-assisted cooling coil has a heat exchanger wrapped

around the direct-expansion (DX) cooling coil, as shown in Figure 1. The air-conditioner inlet air is first pre-cooled 

at the passive heat exchanger. This process improves the latent removal performance of the cooling coil by allowing 

it to dedicate more of its cooling capacity toward dehumidification (lower SHR). The cold air leaving the coil then is 

rewarmed somewhat by the passive heat exchanger and exits the equipment. Similar to the previous TRNSYS 

model (Henderson et al., 2008), a heat pipe heat exchanger was modeled with an average sensible effectiveness of 

32%. 
4 

Figure 1: Heat Exchanger Assisted Cooling Coil Figure 2: A/C with Desiccant Wheel Dehumidifier 

2.2.4 A/C with Condenser Reheat (Case 4): A DX cooling coil with condenser reheat is a type of equipment that can 

actively control the space relative humidity. Under normal operation, the A/C operates to meet the space thermostat 

cooling set point. When the space RH exceeds the set point, the DX cooling coil further reduces the leaving air 

temperature down to meet the space RH set point. The dehumidified supply air is then reheated by the condenser 

coil downstream. A desuperheater module was set in the EnergyPlus model with maximum allowed heat reclaim 

efficiency of 30%. Because the modeled package needs to dehumidify the entire supply air volume to meet the space 

humidity set point, an excessive amount of air conditioning energy may be required. 

2.2.5 A/C with Desiccant Wheel Dehumidifier (Case 5): A desiccant dehumidifier regenerates the desiccant wheel 

with heat rejected by the condenser, as shown in Figure 2. By separating the supply airstream from the regenerative 

airstream, the unit supplies cool and dry air to the home along with reduced A/C runtime. A room air recirculating 

desiccant wheel dehumidifier was used in the model. The model had a SEER 13 DX cooling coil (DXCC), a 

moisture removal capacity of 56.8 L/day, energy factor 3.3 L/kWh, and rated air flow at 250 cfm. Estimated supply 

fan and regeneration fan efficiency is 0.55 W/cfm, counting pressure drop across the desiccant wheel. The default 

desiccant wheel performance curve from EnergyPlus was used. 

2.2.6 A/C with High Efficiency DX Dehumidifier (Case 6): A fairly simple solution for controlling relative humidity 

is a vapor compression dehumidifier. A high-performance 30.75 L/day dehumidifier was used in the analysis with a 

rated energy factor of 2.0 L/kWhr. Performance data was taken from Christensen and Winkler (2009) and it was 

assumed that the normalized performance curves generated from test data could be applied to a similarly configured 

unit of smaller capacity. The DX dehumidifier supplies warm and dry air to the living space since it converts the 

latent heat removed and the electric power consumed to heat rejected to the supply airstream. As a result, operating a 

DX dehumidifier is seen to increase A/C runtime. 

2.2.7 A/C with Standard Efficiency DX Dehumidifier (Case 7): A standard efficiency dehumidifier was included in 

the analysis to determine the energy savings of using a high efficiency unit. The standard efficiency unit was 

assumed to have the same capacity as the high efficiency unit at reduced energy factor of 1.5 L/kWhr (minimal 

EnergyStar cutoff point). Due to the lack of performance data on such a unit, the normalized performance curves for 

the high efficiency unit were applied. 

2.2.8 A/C with ERV and High Efficiency DX Dehumidifier (Case 8): This case combines technologies used in 

Cases 2 and 6. 

2.2.9 A/C with ERV and Standard Efficiency DX Dehumidifier (Case 9): This case combines technologies used in 

Cases 2 and 7. 

3. MODELING RESULTS AND ANALYSIS 

3.1 Predictions of Relative Humidity Excursions 

An RH set point of 55% was used for cases that actively controlled the space relative humidity. Table 2 and Table 3 

show simulation results for RH excursions above 60% and 70%, respectively. Heat Exchanger DX CC

Desiccant Wheel

DX CC

RoomAir

Regen 

SF Supply 

Condenser

EF
5

Table 2: Relative humidity excursions above 60% 

Ref. 

Home

2006 

IECC 

Home

High-performance Home Cases

0 1 2 3 4 5 6 7 8 9

Hrs. Above 60% RH 3,056 3,495 3,141 3,110 2,489 2,023 87 6 0 0 0 0

Number of Excursions 302 263 247 249 254 250 313 19 0 0 0 0

Avg. Exc. Length (hrs) 10.1 13.3 12.7 12.5 9.8 8.1 0.3 0.3 0 0 0 0

Max. Exc. Length (hrs) 70 87 86 75 93 75 0.8 0.8 0 0 0 0

Relative humidity levels reach and maintain unhealthy levels for the high-performance home equipped with only a 

typical air-conditioner (Case 0). The RH exceeds 60% for an 86 hour period and exceeds 70% for a 35 hour period, 

almost guaranteeing mold growth. Adjusting the thermostat in attempt to maintain comfort (Case 1) does little to 

reduce the space relative humidity over the base case. Incorporating an ERV (Case 2) into the house reduces the 

overall number of hours of high relative humidity, but does nothing to reduce the maximum excursion length. 

Similarly, the heat-exchanger-assisted cooling coil (Case 3) also reduces the total number of hours with high 

humidity, but the maximum excursion length is not significantly affected.

Table 3: Relative humidity excursions above 70% 

Ref. 

Home

2006 

IECC 

Home

High-performance Home Cases

0 1 2 3 4 5 6 7 8 9

Hrs. Above 70% RH 1,014 1,304 968 956 717 606 0 0 0 0 0 0

Number of Excursions 175 225 191 192 83 83 0 0 0 0 0 0

Avg. Exc. Length (hrs) 5.8 5.8 5.1 5.0 9.7 7.3 0 0 0 0 0 0

Max. Exc. Length (hrs) 20 32 35 35 43 34 0 0 0 0 0 0

The remaining technologies control space relative humidity quite well. Even though there are periods throughout the 

year where the A/C with condenser reheat (Case 4) and the desiccant wheel dehumidifier (Case 5) cannot maintain 

the 55% RH set point, the maximum excursion length in both cases is less than one hour and does not pose a 

concern for mold growth. The results show that both the standard and high efficiency DX dehumidifier (Cases 6 – 9) 

control the space relative humidity extremely well, which is evident by there being zero hours above 60% RH in the 

living space.

Henderson et al. (2008) examined humidity in a Home Energy Rating System (HERS) reference house (which was 

consistent with the 2004 IECC minimum efficiency standards). That simulation used a single story house with SLA 

of 0.00047, incorporated the Sherman-Grimsrud infiltration model, had no mechanical ventilation and contained a

typical air-conditioner. That work reported that indoor relative humidity exceeded 60% for only 1,017 hours. 

However, modeling results for the reference home and 2006 IECC home in the current study showed that relative 

humidity exceeded 60% for 3,056 and 3,495 hours, respectively, as shown in Table 2.

Table 4 shows a progression of modifying the simulation of the reference house from the current study to match the 

HERS reference house presented by Henderson et al. (2008). The number of stories dictates the stack and wind 

coefficients used by the Sherman-Grimsrud model. The results show that slight modifications in the simulation 

inputs lead to large differences in the predicted relative humidity. By changing the weather data from the typical 

meteorological year (TMY) 3 to TMY2, and the number of stories from 2 to 1, the modeling results showed much 

closer approximation to the past study results. Based on the previous publication dates of similar work by the 

authors, it is likely that weather data from the typical meteorological year (TMY) 2 dataset was used. The remainder 

of the discrepancy in the amount hours exceeding a relative humidity of 60% can be attributed to differences in the 

housing characteristics and assumed occupant behavior.
6

Table 4: Predicted relative humidity sensitivity based on simulation input parameters

Ventilation SLA Infiltration Model Weather 

Data

Number of 

Stories

Hrs. Above 

60% RH

Spot Ventilation 0.00057 Walker & Wilson TMY3 2 3,056

None 0.00057 Walker & Wilson TMY3 2 3,017

None 0.00048 Walker & Wilson TMY3 2 2,747

None 0.00048 Sherman-Grimsrud TMY3 2 2,243

None 0.00048 Sherman-Grimsrud TMY2 2 1,457

None 0.00048 Sherman-Grimsrud TMY2 1 1,359

3.2 Predictions of Thermal Comfort

Figure 1 displays the percentage of people dissatisfied (PPD) based on the predicted mean vote (PMV) with the 

most comfortable region falling between PMV values of ±0.5. The PMV is dependent on the dry-bulb temperature, 

relative humidity, air speed, activity level, and clothing level. A clothing schedule was created to take into account 

of seasonal variation. PMV will generally exceed a value of +0.5 during hot and humid periods. Table 5 displays the 

maximum PMV value and total number of hours exceeding a PMV of +0.5. 

Trends in maximum PMV values and total hours exceeding a PMV of 0.5 do not correlate to the trends in relative 

humidity presented in Table 2 and Table 3. This can be explained by taking a closer look at the ASHRAE comfort 

regions displayed in Figure 4. The comfort regions extend over a fairly large range in relative humidity compared to 

temperature; meaning humans are not as sensitive to humidity as to temperature. This also indicates that the 

humidity problem within a home may not be noticed by the occupants. Despite the variation of hours exceeding a 

PMV of 0.5 in the high-performance home, the PMV exceeds a value of 0.5 for less than 2.2% of the year for all the 

cases. 

Figure 3: Predicted percentage dissatisfied as a 

function of predicted mean vote (ASHRAE, 2004)

Figure 4: Psychrometric chart with seasonal comfort 

regions (ASHRAE, 2009)

Table 5: Thermal Comfort statistics based on PMV

Ref. 

Home

2006 

IECC 

Home

High-performance Home Cases

0 1 2 3 4 5 6 7 8 9

Maximum PMV Value 0.86 0.73 0.69 0.64 0.69 0.68 0.56 0.56 0.60 0.60 0.60 0.60

Hrs. Exceeding 

PMV=0.5 618 308 161 73 186 140 23 54 142 146 152 155

0

20

40

60

80

100

-3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3

Predicted Percentage of 

Dissatisfied (PPD)

Predicted Mean Vote (PMV)

0.000

0.004

0.008

0.012

0.016

0.020

10 15 20 25 30 35

ω (kg/kg)

Dry Bulb Temperature (oC)

60% RH

40% RH

Winter Comfort Region Summer Comfort Region
7

3.3 Energy Consumption Summary

Table 6: Source energy consumption summary for parametric cases (GJ/Yr)

Case 0 Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9

Misc+ Large Appl. 66.40 66.40 66.40 66.40 66.40 66.40 66.40 66.40 66.40 66.40

Lights 9.05 9.05 9.05 9.05 9.05 9.05 9.05 9.05 9.05 9.05

Ventilation Fans 1.95 1.95 4.50 1.95 1.95 1.95 1.95 1.95 4.50 4.50

H/C Fans 4.21 4.27 4.14 4.64 6.19 7.37 4.58 4.61 4.30 4.35

Cooling & 

Dehumidification 30.76 30.89 30.25 33.85 47.05 36.45 44.02 47.05 38.57 40.38

Heating 8.91 9.32 7.71 8.98 10.94 9.32 8.51 8.48 7.30 7.27

Hot Water 9.86 9.86 9.86 9.86 9.86 9.86 9.86 9.86 9.86 9.86

Total 131.15 131.73 131.92 133.84 151.43 140.40 144.38 147.41 140.00 141.81

Percent Increase - 0.5% 0.6% 2.1% 15.5% 7.1% 10.1% 12.4% 6.7% 8.1%

Table 6 shows the annual source energy consumption for the high-performance home cases. Source-to-site 

conversion ratios are 3.365 for electricity and 1.092 for natural gas. Adding active humidity control equipment (Case 

4-9) increases whole house source energy consumption. In the current analysis, A/C with Desiccant Wheel 

Dehumidifier (Case 5) and A/C with ERV and High Efficiency DX Dehumidifier (Case 8) stand out as the two 

options resulting in the smallest increase of source energy consumption. As expected, A/C with Condenser Reheat

(Case 4) results in the highest increase of source energy consumption.

Table 7: Parametric cases HVAC energy consumption summary 

Case 0 Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9

A/C Run Time (Hrs) 1,641 1,654 1,750 1,841 2,625 1,386 1,829 1,856 1,863 1,880

Dehumidifier Run 

Time (Hrs) 0 0 0 0 0 1,288 1,177 1,128 732 688

Vent Fan (kWh/Yr) 161 161 372 161 161 161 161 161 372 372

H/C Fan (kWh/Yr) 347 353 356 383 511 608 378 381 356 358

Heating (kWh/Yr) 736 769 636 742 903 769 703 700 603 600

Cooling & 

Dehumidification 

(kWh/Yr)

2,539 2,550 2,497 2,794 3,883 3,069 3,633 3,883 3,183 3,333

Total HVAC

(kWh/Yr) 3,783 3,833 3,861 4,080 5,458 4,607 4,875 5,125 4,514 4,663

Figure 5: Parametric cases HVAC summary 

0

1000

2000

3000

4000

5000

6000

Case 0Case 1Case 2Case 3Case 4Case 5Case 6Case 7Case 8Case 9

Cooling & 

Dehumidification 

(kWh/Yr)

Heating (kWh/Yr)

H/C Fan 

(kWh/Yr)

Vent Fan 

(kWh/Yr)

Electricity (kWh/yr)
8

Table 7 and Figure 5 are a close up look at the cases heating, ventilation, and air-conditioning (HVAC) annual 

electricity consumption. The energy consumption seen in Figure 5 is a necessary cost of maintaining home 

durability and healthy indoor air quality. Higher-efficiency solutions to space conditioning and humidity control 

may help achieve these requirements. A few observations were made:

• A/C and Standard Efficiency DX Dehumidifier (Case 7) showed a slight increase in A/C runtime over the A/C 

and High Efficiency DX Dehumidifier (Case 8). A/C with Desiccant Wheel Dehumidifier (Case 5) reduced 

A/C runtime.

• The system auto-size option in EnergyPlus reduced A/C cooling capacity when an ERV was used. The 

corresponding A/C runtime did not change much, but overall A/C energy consumption was reduced.

• Operating a standard efficiency DX dehumidifier (Case 7 and 9) showed minimal electrical energy increase 

compared to operating a high efficiency DX dehumidifier (Case 6 and 8). A/C with Desiccant Wheel 

Dehumidifier (Case 5) showed more energy savings compared to A/C and High Efficiency DX Dehumidifier 

or (Case 6).

4. CONCLUSION

The following conclusions were made from the parametric study:

• Prediction of space relative humidity is very sensitive to modeling of natural infiltration and the method of

mechanical ventilation employed. The relative humidity excursion analysis showed that all three homes (mid1990’s reference home, IECC 2006 home, and high-performance home) were prone to mold growth due to 

long excursions of high humidity. 

• Thermal comfort analysis indicates that humidity problems within a home may not be noticed by the 

occupants.

• In the high-performance home (50% source energy savings level), adding active humidity control equipment 

(Cases 4-9) succeeds in effectively controlling relative humidity to a safe level, at a cost of increasing whole 

house source energy consumption by 6.7% to 15.5%.

• The annual HVAC electrical energy analysis showed that standard efficiency DX dehumidifiers (Cases 7 and

9) have minimal electrical energy consumption increase than high efficiency DX dehumidifiers (Cases 6 and

8).

REFERENCES

Conditions that Promote Mold Growth, www.epi.state.nc.us/epi/oii/mold/conditions.html, 2003, Occupational and 

Environmental Epidemiology, North Carolina Department of Health and Human Services,

American Society of Heating, Refrigeration, and Air-Conditioning Engineers, 2004, ASHRAE Standard 55-2004: 

Thermal Environmental Conditions for Human Occupancy.

American Society of Heating, Refrigeration, and Air-Conditioning Engineers, 2009, Handbook of 

Fundamentals.

Anderson, R. and Roberts, D., 2008, Maximizing Residential Energy Savings: Net Zero Energy Home Technology 

Pathways, NREL/TP-550-44547.

Christensen, D. and Winkler, J., 2009, Laboratory Test Report for Thermastor Ultra-Aire XT150H Dehumidifier, 

NREL/TP-550-47215.

U.S. Department of Energy (DOE), 2009, EnergyPlus version 4.0.

Henderson, H., Shirey, D., Rice, C.K., 2008, Can Conventional Cooling Equipment Meet Dehumidification Needs 

for Houses in Humid Climates?, 2008 ACEEE Summer Study on Energy Efficiency in Buildings.

Hendron, R., and Engebrecht, C., 2010, Building America Research Definition: Updated December 2009, 

NREL/TP-550-47246.

International Code Council, Inc. (ICC), 2006 International Energy Conservation Code.

Walker, I. and Wilson D., 1998, Field Validation of Equations for Stack and Wind Driven Air Infiltration 

Calculations, International Journal of HVAC&R Research, Vol. 4, Issue 2.
F1147-E(10/2008)

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ARRB.0200

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401-3393

8. PERFORMING ORGANIZATION

REPORT NUMBER

NREL/CP-550-48383

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S)

NREL

11. SPONSORING/MONITORING

AGENCY REPORT NUMBER

12. DISTRIBUTION AVAILABILITY STATEMENT

National Technical Information Service

U.S. Department of Commerce

5285 Port Royal Road

Springfield, VA 22161

13. SUPPLEMENTARY NOTES

14. ABSTRACT (Maximum 200 Words)

A parametric study was conducted using EnergyPlus version 4.0 to analyze the impact of various dehumidification 

equipment and control strategies on a typical mid-1990’s reference home, a 2006 IECC home, and a highperformance home in a hot humid climate.

15. SUBJECT TERMS

energyplus; dehumidification; parametric study; building america

16. SECURITY CLASSIFICATION OF: 17. LIMITATION 

OF ABSTRACT

UL

18. NUMBER 

OF PAGES

19a. NAME OF RESPONSIBLE PERSON

a. REPORT

Unclassified

b. ABSTRACT

Unclassified

c. THIS PAGE

Unclassified 19b. TELEPHONE NUMBER (Include area code)

Standard Form 298 (Rev. 8/98)

Prescribed by ANSI Std. Z39.18