In article ,
Mark & Juanita wrote:
Robert Bonomi wrote:

... snip
Our HVAC technicians would prefer just letting the systems run
full time and maintain a steady temperature, especially when
equipment is new just to run it through its paces while under
warranty. The Energy Czar tends to win. I will try to remember
to ask tomorrow about the whys.

A 'medium-insulated' school building full of people doesn't need _any_
additional heat source until the outside temperature gets below about
-20F.

Look up how much heat an 'at rest' human body gives off, and multiply by
the 25-30 bodies preset in the average classroom.


From EDEE 101 (or Physics 112), we were told that the average human body
is equivalent to 100 watt light bulb as far as heat output.

That's a bit on the low side -- about right for sleeping. 'resting' is more
in the 110-120 range. Circa 125 is frequently used for estimating purposes.

Call it 12,000 BTU/hr per room, plus another few thousand for the lighting.

Scale up by a factor of 4, for equivalent footage to a medium house,
and you've got the equivalent of an 80% efficient 150,000 BTU/hr furnace
running at a _50%_ duty cycle.

Depending upon
age, kids in a school would most likely be considerably less.

Surprisingly small differences. lower elementary ages are about 75-80% of
adult.

Getting the heat _out_ of the building is the issue.

At 'above zero' temperatures, it's _common_ to be venting hot air outside
and pulling in cold outside air for 'make-up'.

Not infrequently, the chillers will be running, in addition.