ASHRAE Journal - September 2013 - 64

2013 ASHRAE TEcHnology AwARd cASE STudiES

time. Use of rainwater at this station is predicted to save
more than 58,000 gallons (220 000 L) of potable water
each year.
A full measurement and verification plan was incorporated including submetering of individual end uses.
Each individual system is metered to allow for optimization of energy performance throughout the building. Data logs from this system were used to identify
operational problems during early occupancy and to
adjust settings to optimize performance. This system
allows for feedback to the occupants regarding energy
usage. Even in the most efficiently designed building,
occupant habits can drive up energy use. With the M&V
system provided, the city manager plans to implement a
feedback system that will allow for friendly competition
between the three shifts. This attempt to provide feedback directly to the building users and involve them in
the energy efficiency of their building will be necessary
to achieve truly high performance buildings.

Operations & Maintenance
Primary heating and cooling delivery is through
extremely durable and low maintenance radiant
slabs. No mechanical equipment is located outdoors.
Geothermal bores take the place of outdoor heat
exchangers. The ERV is located in the mechanical
room, and a split system for elevator cooling is located
in the equipment bay. The only mechanical system
items exposed to the weather are the solar thermal and
photovoltaic panels. Regular maintenance of HVAC
equipment only involves cleaning filters of the ERV.
Pumps, valves, and water-to-water heat pumps are all
relatively long lasting and easy to maintain.

Cost Effectiveness
The high level of energy and water efficiency
included in the project fit well within the budget for
the station. The final cost of the station was about $6.6
million, which is $1.4 million under the original cost
estimate by the city. The utility costs for this station will
be low with bills reduced to less than one-quarter of
a typical regional station. Investment in measures to
achieve low operating costs makes good sense for the
fire district as raising money for new capital expenses
is generally easier than getting budgets for ongoing
annual expenses.
The high level of envelope insulation in this building allowed for the mechanical system to be sized at
64

ASHRAE JouRnAl

ashrae.org

Septem ber 2013

roughly one-third the capacity of a standard practice
approach. This station has only 10.4 tons (36.5 kW) of
ground loop capacity to provide all heating, cooling, and
hot water. This is about 1,200 ft2 (112 m2) of building per
ton of installed capacity. Typical rule of thumb sizing in
commercial buildings in the Pacific Northwest is about
400 ft2/ton (10.6 m2/kW). This approach shifts money
from the mechanical system budget into other energyefficiency features of the building.

Environmental Impacts
The local water supply comes from deep ground
wells. This municipal system has a limited capacity and
requires a great deal of pumping energy. By capturing
and using rainwater for all non-potable uses, the building reduces the impact on the local system by more than
58,000 gallons (220 000 L) per year.
If this fire station were built to typical standards it
would use over three times as much energy annually. This translates to a reduction in over 150,000 lbs
(680 kg) of CO2 per year that is not released into the
atmosphere. Direct reduction of water, materials, and
energy use are very important. However, perhaps the
most important environmental impact is the example
that it sets for the entire community. Station 72 has a
mission of maximum resource efficiency and minimum energy expenditure given its critical role should
its community be in crisis. Fire Station 72 is located
in downtown Issaquah and abuts a very busy transit
center. The station provides community education
and a high level of visibility for energy efficiency and
sustainable “green” buildings. The rainwater cistern
and solar panels are visible from the street and transit
station, and there is a reader board kiosk located at
the transit station that reports the energy use of the
station alongside the energy production of the solar
electric system.
Fire fighters are a traditionally conservative group and
are almost universally respected by the community. To
have the fire fighters visibly embrace sustainable buildings and practices helps to further convince the community that high performance buildings are an appropriate
response to climate change and dwindling resources
that will impact future generations.

References
1. Baylon, D. 2008. Baseline EUI of the 2002-2004 Nonresidential Sector:
Idaho, Montana, Oregon, and Washington. Ecotope. Prepared for the
Northwest Energy Efficiency Alliance.

ASHRAE Journal - September 2013

Table of Contents for the Digital Edition of ASHRAE Journal - September 2013