# Presentation: 456072

## Overview of Collected Integrated Chiller Retrofit Case Studies

**Dr. Lisa Gartland**
**(510) 595-7674, positivenergy@california.com**

## Integrated Chiller Retrofit Case Studies

**Cool $ense workshops have been held around the country**
** ****Boston, Denver, San Diego, Kansas City, Atlanta, and Washington D.C.**
**Case studies collected in each region**
**most are highly integrated retrofits**
**all exemplify aspects of the Cool $ense message**

## Integrated Chiller Retrofit Case Studies

**Overview of collected case studies**
**chiller retrofit/replacement examples**
**cooling system improvement example**
**building load reduction example**
**integrated retrofit economics**
**how retrofits can be improved**
**Details of individual case studies are on the Cool $ense web site**
**http://eetd.lbl.gov/CoolSense**

## Integrated Chiller Retrofit Case StudiesChiller Retrofits/Replacements

**Most of my case studies start with and keep electric centrifugal chillers**
**don’t often switch to gas-fired or absorption chillers**
**Significant efficiency gains**
**original full-load efficiencies of 0.72 to 0.90 kW/ton**
**replacement efficiencies of 0.48 to 0.65 kW/ton**
**Total capacity stays about the same **
**260 tons/100,000 square feet “before”                          245 tons/100,000 square feet “after”**

## Integrated Chiller Retrofit Case StudiesChiller Retrofit Example

**Lawrence Street Center**
**Denver, CO**

**office space **
**radio stations**
**140,000 square feet**
**14 stories**
**built in 1982**

**400 ton electric chiller**
**R-11 refrigerant**
**0.72 kW/ton efficiency**
**Less than 15 years old**
**Operating at 60% capacity**

**Chiller “Before”**

## Integrated Chiller Retrofit Case StudiesLawrence Street Center - Chiller Retrofit

**Driveline retrofit, replaces the driveline, including starter, motor, compressor, purge unit and controls**
**Kept old heat exchanger**
**checked condition of shells & tubes condition with eddy current testing of condenser & evaporator**
**Capacity reduced from 400 tons to 290 tons**
**Full load efficiency of 0.59 kW/ton**

**Chiller “After”**

## Integrated Chiller Retrofit Case StudiesChiller Replacement Example

**Two 2750-ton electric chillers**
**installed in 1970, estimated efficiency 0.85 - 0.9 kW/ton at full load**
**R-12 refrigerant, no refrigerant containment system**
**Never run the second chiller & often running at part-loads**
**48-49°F discharge water temperatures, not meeting design 42°F**

**Chiller “Before”**

## Integrated Chiller Retrofit Case StudiesKansas City Intl Airport - Chiller Replacement

**Three 1500-ton electric chillers**
**more flexible staging capability than with the 2 larger chillers**
**R-134a refrigerant**
**efficiency of 0.65 kW/ton at full load **
**saving about 0.25 kW/ton**
**Running closer to full-load capacities for higher efficiencies**
**Meeting 42°F design water discharge temperature**

**Chiller “After”**

## Integrated Chiller Retrofit Case StudiesCooling System Improvements

**Most common cooling system improvements **
**replacement of cooling towers**
**new, more efficient fans, pumps & motors**
**addition of economizer or evaporative cooling**
**new air handler units with variable volumes**
**automated control systems to integrate building operation with outside conditions and indoor loads**
**Rarer cooling system improvements**
**thermal storage **
**heat recovery systems**

## Integrated Chiller Retrofit Case StudiesCooling System Improvements

- Need to reduce demand and on-peak electricity consumption
- One 275 ton electric chiller & 208 tons of rooftop units
- CFC-11 refrigerant, 0.75 kW/ton efficiency
- Building expanding by 50%, or 70,000 square feet
- Plenty of room for equipment

**“****Before” Scenario**

## Integrated Chiller Retrofit Case StudiesRhode Island Hospital Trust Building

**Ice storage system**
**390 ton brine chiller, three 761 ton-hour ice banks**
**create ice at night, cooling load diverted to ice banks during day**
**390 ton high efficiency brine chiller**
**meets summer loads in building and computer room**
**Rooftop units originally cooled computer room all year **
**retrofit with chilled water coils & hooked up to heat exchanger**
**original rooftop units kept for backup capability**
**Added variable speed drives, high efficiency motors, EMCS**
**T-8 fluorescent lights used with occupancy sensors**

## Integrated Chiller Retrofit Case StudiesBuilding Load Reductions

**Lighting Improvements**
**most projects add T-8 lamps & electronic ballasts**
**fewer use low energy incandescents & exit signs**
**occupancy sensors could be used more often**
**additional daylighting rarely introduced and/or compensated for by lighting sensors**
**Wall and window upgrades to reduce loads**
**low-emissivity films used fairly commonly**
**insulation is rarely increased**
**surface reflectivities never increased**

## Integrated Chiller Retrofit Case StudiesBuilding Load Reduction Example

**New York Life Building**
** ****Kansas City, MO**

**office space  220,000 square feet   12 stories                 built in 1888**

**New energy-efficient windows**
**double-pane, low-e, insulated frames**
**custom-made operable windows**
**Exterior masonry walls**
**R-11 fiberglass insulation added**
**New roof with R-20 insulation**
**5-7 year paybacks**

**Envelope Measures**

## Integrated Chiller Retrofit Case StudiesKansas City’s New York Life Building

**Overhead lighting **
**T8 Fluorescent tubes**
**solid-state, low-energy, dimmable ballasts **
**Daylighting **
**ceilings slope down from windows to reflect light into interior**
**interior light shelves, light reflective colors**
**Computer-controlled system**
**adjust overhead light levels according to the amount of daylight**
**occupancy sensors turn off lights when no one is present**
**3-4 year paybacks**

**Lighting Measures**

**Saved $0.50 to $0.80 per square foot**
**Comfortable, modern office building with historic character**

## Integrated Chiller Retrofit Case StudiesIntegrated Retrofit Economics Example

## Integrated Chiller Retrofit Case StudiesImproving Integrated Retrofits - Chiller Sizing

**New 600 ton electric centrifugal chiller, about to be installed **
**in Boston’s Hurley Building.**

**This chiller replaces an equal **
**capacity chiller, despite lighting **
**load reductions and increased **
**system efficiencies!**

**Know your building loads both before & after retrofit work!!**
**Downsize, rightsize or stage your chillers to most efficiently meet these loads!**

## Integrated Chiller Retrofit Case StudiesImproving Integrated Retrofits - Higher Motivations

**Most common motivations**
**CFC phaseouts**
**equipment age or imminent failure**
**high utility bills or increasing fuel costs**
**rebate programs**
**Motivations leading to the “best” retrofits**
**comfort or indoor air quality problems**
**environmental concerns or energy efficiency goals**
**extensive building renovation**

## Integrated Chiller Retrofit Case StudiesSet Challenging Goals

**Green Building **
**San Diego, CA**

**office space**
**73,000 square feet**
**3 stories**
**built in 1981**

**Goal of four year payback in terms of energy savings**
**High levels of energy & environmental performance **
**use less than 9 kWh per square foot annually**
**use environmentally friendlier materials**
**Model for sustainable building practices in San Diego**

## Integrated Chiller Retrofit Case StudiesGreen Building’s Goals Were Met

**Used 8.0 kWh/sq.ft, meeting 9kWh/sq.ft. goal**

## Integrated Chiller Retrofit Case StudiesSummary

**Integrated retrofit projects CAN combine**
**high energy efficiency**
**innovative technology for chillers, thermal storage, air handling, lighting, etc.**
**financial viability**
**When it’s time to replace your chiller**
**set high goals for your building,**** then meet them!**