With the astronomical start of summer less than fortnight
away, now’s a good time take a closer look at your HVAC system and determine
where you can increase efficiency and positively impact your bottom line. In
general, HVAC systems account for more than 30% of a building’s electricity
costs, and there are now several technological improvements—including
building envelopes and energy management systems (EMS) —that
can help you reign in your HVAC–related energy use.
Let’s
start out with the low-hanging fruit first. According to the Energy Coalition—a
California-based nonprofit that
promotes energy efficiency and awareness—you can
save up to 10% of our cooling cost just by raising your AC thermostat by 5
degrees. Another easy way to
tweak your system is to make sure you’re using energy-efficient equipment
(including Energy Star products). Upgrading your building’s heating,
ventilation, and AC (along with maintaining air filters) can also help your HVAC
system run efficiently.
If
you want to take it to the next level, EMS combine intelligent energy control
(typically, a thermostat combined with an occupancy sensor and light-level
sensor) to fine-tune an HVAC system, so that energy-saving settings kick in when
a space is unoccupied. While
these EMS are most commonly used in a hotel setting, there’s no reason to
believe they couldn’t be adapted to other environments. Another important tool
involves real-time feedback to the user in order to influence energy use from
the customer side of the equation. When a smart thermostat employs a real-time
data display, the customer or user can make an informed choice regarding heating
or cooling particular indoor space.
Building
envelopes add yet another level of indoor environment control. The building
envelope—also known as a structure’s outer shell—provides a barrier between
interior and exterior environments, thereby creating a “thermal barrier” between
the fluctuating elements of the outside world and a controlled indoor-space.
While most buildings have adequate barriers created by walls and windows, most
structures are vulnerable at the connection point between the two. That’s where
a more complex building envelope design comes into play, and where the envelope
itself can most impact HVAC needs and demands. According to Michael T. Kubal’s,
Waterproofing the Building Envelope, a building experiences up to 90% of all water
intrusion problems within only 1% of the building’s exterior surface
area—and water intrusion has
big consequences, including health and comfort issues, as well as increasing
HVAC loads in excess of 40%. According to a report by the Building America
Research Team (a DOE program), building high-performance building envelopes can
significantly improve energy, because a sophisticated and advanced building
envelope can actually reduce a building’s energy needs, thereby allowing for
smaller HVAC systems.
So
as the summer heat creeps along, and your building’s thermostat works hard to
keep occupants cool and comfortable, take the time to evaluate your HVAC system
and see if combining efficiency with a little bit of knowledge can help you
reduce your electricity needs and cut down on your energy
expenses.