Commercial Architecture July 2018 - 28

PROJECT

hvac
the gap between laboratory test data and realworld HVAC system performance, including
installation and utility costs against calculated
load and actual local weather.
"BEER rerates published efficiency data for
actual operating conditions and any distribution energy that's missing from AHRI data,"
said Mark Handzel, vice president of product
regulatory affairs at Xylem, Rye Brook, NY (xylem.com). "For example, pumping energy in a
hydronic system is absent from AHRI numbers.
And when VRF systems are AHRI tested in a
lab, the demands on the compressor, based on
length of refrigerant lines and load applied, are
far less than what a typical field installation is
likely to include."
This type of rerate is applied in BEST according to American Society of Heating, Refrigerating and Air-Conditioning Engineers,
Atlanta (ASHRAE, ashrae.org), guidelines.
Certified manufacturers publish data to all sys-

With BEST, professionals can rapidly analyze all the real-world HVAC options to determine the system that best meets budgetary and performance requirements.

tems by identifying, by system, where energy is
used to deliver comfort. These rerates are standard defaults in BEST, where most other pro-

ing Technologies Office (BTO, energy.gov/eere/buildings/building-technologies-office).

grams require users to make their own adjustments.
While a building's heating, cooling, and ventilation energy

"While different types of HVAC equipment are subject to var-

consumption and operating cost is of great importance, the intent

ious rating systems, the bigger issue is that they're all tested to

of BEST is not to predict annual energy consumption of a given

different standards," said Greg Cunniff, manager of application

system.

engineering at Taco Comfort Solutions, Cranston, RI (tacocomfort.com).

Rather, BEST seeks to provide the user with a comprehensive
comparison of multiple, complete HVAC systems using an identi-

"The testing parameters, lab procedures, and resulting efficien-

cal load profile, specific to building size, weather pattern, and in-

cy scores for some types of equipment are relatively comparable

stallation and operating cost. BEST reports, in detail, the infor-

to their real-world performance," added Cunniff. "For other sys-

mation needed for informed decisions regarding HVAC system

tems, the discrepancy between tested and as-applied performance

selection at the early project design phase.

is surprisingly large. Owners, engineers, and contractors needed a

"BEST outputs cumulative lifecycle cost by year, system pay-

tool that refines the choices and compares all technologies on

back time, pump and fan HP, total system integrated energy effi-

common ground."

ciency ratio (IEER) for cooling, coefficient of performance (COP)

"With BEST, professionals can rapidly analyze all the

for heating, and more," explained Mark Chaffee, Taco vice presi-

real-world HVAC options to determine the system that best meets

dent of governmental relations & sustainability, and founding

budgetary and performance requirements," said Rick Bostian,

member of the HIA-C. "The cost data is based on industry aver-

HIA-C chairman and business-development manager at Water-

ages for first cost and maintenance costs collected from over 50

Furnace International, Ft. Wayne, IN (waterfurnace.com).

contractors around the U.S." Five years in the making, BEST al-

"In its most basic comparison function, the user only inputs

ready has roughly 2,000 registrants. CA

the location for weather and utility data, building size, and number of stories to get a comparison of four options among the 30
predetermined systems," Bostian continued. "If desired, the design team can change any of the program's defaults to more closely match the building. Without BEST, comparing a lot of 'what if '
scenarios can be expensive and time consuming."
BEST uses the Building Energy Efficiency Ratio (BEER),
which combines certified Air Conditioning, Heating, Refrigeration Institute (AHRI, ahrinet.org) data, including certified unit
efficiency ratios, manufacturers' published performance data,
component performance curves, and the pipe or duct required in
typical systems with "as applied" correction factors. BEST bridges
28

COMMERCI A L A RCHI T EC T URE

JULY 2018

commercialarchitecturemagazine.com

Want more information?
To download the information listed below, visit
commercialarchitecturemagazine.com/1807best.

Circle 3 on the Reader Service Card.
Download BEST.

http://www.xylem.com http://www.ashrae.org http://www.energy.gov/eere/buildings/build http://www.fort.com http://www.waterfurnace.com http://www.commercialarchitecturemagazine.com/1807best http://www.ahrinet.org http://www.commercialarchitecturemagazine.com

Table of Contents for the Digital Edition of Commercial Architecture July 2018