Building maintenance is important for the energy-efficiency
performance of your facilities, both on a regular basis and as a more thorough
"building tune-up." A building tune-up, the second stage of the ENERGY STAR
buildings upgrade strategy, involves a series of simple, low- or no-cost adjustments to
existing building equipment.
These measures can result
in an energy savings of 5 to 15 percent and have an average return on the investment of 35
percent. A building tune-up can also help prepare a building for a comprehensive
energy-efficiency upgrade. To begin a building tune-up, follow these three important
Secure the building
envelope from infiltration
Test all building systems
Once building controls are calibrated as they were intended, you can begin evaluating
which systems in your building need to be adjusted or upgraded. The first step is to
calibrate indoor and outdoor building controls, such as room thermostats, duct
thermostats, humidistats, and pressure and temperature sensors, to be in accordance with
the original design specifications.
Next, inspect damper and valve controls to make sure they are functioning properly. Check
pneumatically controlled dampers for air leaks and ensure that they open and close
properly. Except for buildings with heat pumps, another energy saving measure is to turn
temperature controls down at night in the winter and up in the summer to avoid unnecessary
heating or cooling losses. And, if applicable, make sure that your cooling tower and
humidity-based air economizers are working properly at start up.
Locate Air Leaks
By reducing air infiltration in to and from the building envelope you can enhance occupant
comfort and reduce heating or cooling errant air. Tighten the building by locating all air
leaks in the windows, doors, walls, and roofs. indications of air leaks are drafts near
doors and windows, and also heat build-up in upper floors of building (chimney effect).
Seal Off Leaks
Once you have detected the air leaks, seal them with appropriate materials and techniques
such as weather-stripping on doors, sealing and caulking on windows, and proper insulation
distribution in walls, ceilings and roofing. If your building is equipped with revolving
doors you should encourage their use to reduce drafts and conditioned-air loss.
The TAB (Testing,
Adjusting, Balancing) Analysis
Conducting a testing, adjusting, and balancing (TAB) analysis of building systems involves
investigating the current state of the system and making adjustments to run it close to
its original design specifications. Since occupancy levels and space utilization of a
building may change dramatically over time, the TAB process can improve occupant comfort
and save energy costs by increasing the efficiency of the system.
For a TAB analysis of a
typical HVAC system, you should investigate
air and water system flow
heating and cooling
systems' delivery temperatures
positions and functioning
of flow control devices for air and water delivery systems
control settings and
fan and pump speeds and
Air delivery and water system items to be checked include outside-and mixed-air dampers
and coil-mixing valves. Pneumatic control systems, which are the "blood stream"
for many larger HVAC systems, also require maintenance for the controller to properly
regulate the position of the valve or damper operator.
An annual check of the
compressors for main control air can prevent the main-air lines from becoming contaminated
with water or oil. A refrigerated air drier can remove water from the air supply by
cooling the compressed air as it leaves the receiver tank, thereby condensing the moisture
and depositing it into a drain.
(such as coalescing air filters) can remove oil from the main-air supply. Main and branch
air lines should also be checked for leaks or blockages, which typically occur at or
between sensing elements (thermostats, etc.) and control devices (valve or damper
Such leaks or blockages
in the lines create losses in pressure that affect the overall system operation by
providing incorrect pressure signals to the controlling devices, and may even render an
control device inactive. Calibrating the control devices and elements approximately every
four months will promote the system's optimal performance.
Clean All Surfaces
Finally, ensure that all heat transfer surfaces and filters are clean. Dirty surfaces
reduce heat transfer, increase pressure loss, and increase energy use. Take the following
measures to keep surfaces and filters clear:
Clean the airside of
heating and cooling coils, whether in an air handler or in a rooftop unit, to reduce dirt
and deposit build-up.
Check for and clean dust
build-up in baseboard-heating systems.
Clean and replace, as
necessary, filters for both airside and waterside systems.
4. Avoid covering or
blocking terminal fan-coil units and baseboards. Besides creating a fire hazard (in the
case of radiators), blocking the units prevents proper air circulation and renders heating
and cooling inefficient.
A building maintenance
program can be a relative inexpensive, yet profitable part of your building operation. The
ENERGY STAR Buildings upgrade strategy integrates building tune-ups as a part of a
comprehensive approach to overall building efficiency improvements. To learn more about
other building tune-up measures and how they fit into your upgrade strategy, check out
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