ASHRAE Journal - April 2014 - 67

2014 ASHRAE TEcHnology AwARd cASE STudiES
nology

Above Laboratory exhaust air valve arrangeCourtEsy WsP usA

ment emphasizes accessibility.

Left Central boiler room designed for

intuitive systems operation and hassle-free
maintenance.

Energy Efficiency
Laboratories have a well-deserved reputation for
consuming large amounts of energy, especially in cold
climates. The ASHRAE Laboratory Design Guide was implemented extensively to help reduce energy use while
maintaining a safe work environment for its occupants.
Both supply and exhaust ventilation systems use variable
air volume control. Exhaust airflow rate is controlled to
maintain the desired ventilation rate in air changes per
hour (ach). Supply airflow rate is offset from exhaust airflow rate to provide precise room pressure control.
The facility uses three separate manifolded laboratory
exhaust systems. Types and concentrations of chemicals
used, lower first cost, fewer stacks, simple connection to
exhaust air heat recovery and excellent exhaust air dilution made this the logical system choice for this laboratory application.
Runaround loop heat recovery coils were implemented
for each of the three separate 100% outdoor air laboratory ventilation systems. This heat recovery method was
selected to eliminate any concerns with cross-contamination. Each exhaust air heat recovery coil is preceded
by a MERV 8/MERV 13 filter bank. Filter air pressure
drop is monitored through the central building automation system (BAS) to ensure the coils are maintained
clean for maximum energy savings.
Toilet rooms, janitor closets and other spaces requiring 100% general exhaust ventilation were tied into the
laboratory exhaust fan systems using exhaust air control
valves; eliminating many small exhaust fans and allowing the runaround loop heat recovery systems to recover
as much general exhaust air energy as possible before
leaving the building.
Six modular, high efficiency, fully modulating, gas-fired
boilers provide precise hydronic heating control with a
minimum turndown to 8% of the building's design heating

day load. Variable-speed drive hydronic heating pumps
precisely match system flow with heating demand.
Energy analysis software package eQUEST v3.61 was
used to model the facility's annual energy consumption.
The HVAC system was zoned and modeled based on the
actual architectural building envelope to the maximum
extent practical. Composite U-values were calculated
from the many detailed architectural roof, wall and
floor cross sections. Heating and cooling system input
was very representative of the actual mechanical design.
Lighting levels and control features were modeled for
each room based on building wide averages. Estimated
plug and task lighting loads were combined and applied
equally throughout the building.
Utility energy consumption data for 2012-13 was collected for comparison to energy model predictions.
Results show an over prediction of electrical energy
and demand and an under prediction of fuel gas usage.
Overall agreement is good.
The Laboratories for the 21st Century (Labs21) benchmarking database tool was used to gauge overall success
of the energy reduction design goals compared with peer
facilities. In 2008, this facility was predicted to use approximately 242 kBtu/ft2·yr (763 kWh/m2·yr) of site energy, well
below the 277 kBtu/ft2·yr (874 kWh/m2·yr) average for peer
Labs 21 database facilities. During the 12 months of operation from June 2012 through May 2013, actual energy usage
was 152 kBtu/ft2·yr (480 kWh/m2·yr), 37% less than anticipated. Energy costs were predicted at $346,000 per year.
Actual energy cost was $284,000, 18% less than predicted.

Indoor Air Quality
The HVAC design follows the recommended practices
of ASHRAE Standard 55-2004 for thermal comfort.
Room temperature and ventilation system airflow are
managed based on user activity and clothing. Building
Apri l 2014

ashrae.org

ASHRAE JouRnAl

ASHRAE Journal - April 2014

Table of Contents for the Digital Edition of ASHRAE Journal - April 2014