true cost of ownership over time.
What are your maintenance costs
and energy costs going to be?”
The industry is also seeing
greater integration of HVAC controls with other building controls,
particularly advanced lighting. For
example, a sensor in a classroom
might be used to control the lighting in that space, as well as the
operation of the room’s unit ventilator. Access controls for security
can also be compatible with HVAC
4. Variable Speed Controls
Although HVAC equipment is
traditionally designed to operate
at peak load – the biggest expected
heating or cooling load – it spends
most of its time operating at part
load. The industry, therefore, is
seeing an uptick in more efficient
variable speed controls.
“There’s a lot of heating and
cooling systems that may be fairly
oversized because those peak loads
are only happening a really small
portion of the year,” Janssen
explains. “Now, you’re seeing
equipment that’s more right-sized
for the applications, and it’s gotten
very efficient at operating at those
variable load conditions. So you’re
seeing higher efficiency and less
5. Variable Refrigerant Flow
This type of HVAC system, as
opposed to a traditional split AC
system, has seen growth. Again,
Janssen explains, they have a higher first cost but also have low ongoing energy and maintenance costs.
VRF allows for an individual level
of control, which can be appeal-
ing to your building occupants,
VRF also operates well in part
load and can respond quickly when
you’re coming out of a set point.
For example, if over the weekend
the building’s temperature was
set back for the lack of occupancy,
it can quickly return on Monday
morning when people come back
into the building.
As HVAC trends and technolo-
gies evolve, facilities managers will
likely notice more moving parts
and more predicative calculations.
Janssen reiterates that it’s best
to avoid overriding some of those
parameters. Work with a controls
contractor to flesh out any issues
and consider retrocommissioning
if need be.
An overwritten system “may not
be operating the way it was intended,” he explains, “so going back in
and getting things back to the way
they were – we always see a lot of
potential there.” B
Sarah Kloepple (sarah.kloepple@
buildings.com) is a staff writer for
VARIABLE REFRIGERANT FLOW SYSTEMS have seen growth. They have a higher first cost but also low ongoing energy and
maintenance costs. Their individual level of control is appealing to occupants.
HVAC TRENDS and technology
are evolving. Have a dialogue
with your controls contractor
about your equipment.