If having one compression tank is so
good, are multiple tanks even better? Not
really. Multiple tanks can be accomplished
using adequate controls and pressure
monitoring, but usually it is not a contest
where having the most toys wins. Having
multiple tanks can create unexpected pres-
Multiple compression tanks can
create unexpected pressure
changes in your hydronic system.
sure changes in your hydronic system,
especially at the pump suction. This is particularly important if your existing facility
just connected to a district energy hydronic
system with a direct connection – or without a heat exchanger acting as a pressure
interceptor. The building’s existing compression tank should be valved off or preferably removed, unless there are extenuating
circumstances such as valving off your
building and using existing boilers and
chillers to self-generate in an emergency or
planned dispatchable condition. In this case,
the compression tank may be re-energized
to keep the system operating correctly.
So now that I have ‘expanded’ your
knowledge (pun intended) and unconfused
you about compression tank use, I can get
back to decompressing with my favorite
adult beverages (I am in Wisconsin, ya
know!) and listen to an appropriate ZZ Top
song with another great guitar riff: “It’s
got me under pressure.”
Steve Tredinnick, PE, is vice
president of energy services
for Syska Hennessy Group in
Madison, Wis. He has more
than 24 years' experience
related to building heating,
ventilation and air-conditioning systems. The past 13 years
of his work have been focused on district
energy systems. Tredinnick is a graduate of
Pennsylvania State University with a degree in
architectural engineering. He is a member of
IDEA and ASHRAE and is currently chair of
ASHRAE TC 6. 2 District Energy. Tredinnick may
be reached at stredinnick@syska.com.
Column and previous columns available at
www.districtenergy.org/de_magazine.htm
