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paste starts getting low, you squeeze the
tube to get the last little bit of toothpaste
out? It was easier to do back when the tubes
were metal, because you could roll them
up and really get that last little drop. Today
the tubes are plastic, and it is a little more
difficult to get every last drop. But we still
try and get every last bit of toothpaste out of
that $2.00 tube.
By now you are probably wondering
where the heck I am going with this, but
bear with me. We as an industry pride our-
selves on our ability to create and maintain
high levels of efficiency for our customers.
But are we doing all we can to “squeeze the
tube” of efficiency from those systems? Here
are a few ways you can help your customers
get all they can out of their equipment.
Insulate the pipes.
A warm basement
is a good indication that heat is being lost
through the piping. There is inevitably
going to be some heat lost from the boiler
unless the boiler is very new and well
insulated. Older cast iron boilers only had a
thin fiberglass blanket of insulation, which
was better than nothing but not much.
By insulating the pipes, you make sure that
most of the Btus created by the boiler reach
their final destination. Insulating the pipes
is even more critical in a steam system.
If the pipes are not fully insulated all the
way to the end of the run where it transi-
tions to the return, the steam can condense
in the main and never get to the radiators.
Clean the system inside and out.
We all know that soot is a great insulator.
No matter how clean your fire is, there is no
such thing as perfect combustion, so even
on a finely tuned burner, there will always
be a small amount of soot left over. This
built-up layer of soot insulates the boiler
from the heat of the flue gas and it takes
longer to transfer the energy to the water
inside. A good cleaning of the fire side will
allow the boiler to transfer heat quicker to
the water side and ultimately use less fuel.
One area to clean that we may not have
considered as part of our maintenance pro-
grams is the inside of the system. Systems
that contain mixed metals, i.e. cast iron,
steel, brass, and copper, corrode and form
iron oxide and magnetite. We are all familiar
with that smelly, black boiler water. The
black color comes from the iron oxide mag-
netite suspended in the water. This material
over time will coat the inside of the pipes
and radiators and form an insulating barrier.
The heating system takes longer to transfer
the energy from the water through the
copper pipe resulting in higher fuel usage.
By cleaning the inside of the system with a
cleaner like Fernox F-3 or F-5, the system
performance will noticeably improve.
Add some intelligent control strategies
and make it a “smarter” system.
A smart
control such as the Taco “Fuel Mizer” will
make the boiler weather responsive, and
rather than run up to the high limit it will
shut off at a lower temperature, depending
on the outside temperature. Studies have
shown that the addition of outdoor reset
reduces fuel usage by an average of 14
percent.
Another way to squeeze more efficiency
out of the system is to replace multiple
circulators with zone valves and a “smart”
pump. A Delta T pump has the ability
to recognize the amount of energy being
drawn out of the system by looking at the
temperature difference between the supply
and return. When the Delta T shrinks,
it means the system requires fewer Btus,
and the pump slows down. By varying
the speed of the pump in this manner,
the system is supplied with only as much
energy as it requires.
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What about water heating? Does the
boiler have an internal coil that keeps
it 180 degrees 12 months of the year?
Do your customer a favor and recommend
an indirect. Maybe suggest some solar
thermal to go along with it. Between State
and Federal rebates, solar thermal can be a
very attractive option.
But before we recommend any of the
above, let’s take a quick look at the obvious
– dust! Whether it’s baseboard, radiators or
convectors, dust can be efficiency’s biggest
enemy. No matter how often you clean,
you will eventually accumulate enough
dust on those fins or radiator surfaces to
have a significant impact on their overall
performance.
Be tactful when you discuss this with the
lady of the house. Instead of saying that her
emitters are harboring dust balls, explain
that electrically charged dust is constantly
moving in the air and that the nature of
convection is such that these particles will
come into contact with heating surfaces and
stick to them. And in order to extract as
much efficiency as we can we need to make
sure that those emitters can do their job as
they were designed.
If fact, you might suggest to the hom-
eowner that it’s a lot like squeezing that
tube of toothpaste …
Energy Efficiency
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By Bruce Marshall, Emerson Swan
