re: installing generator in the garage?
18 oct 2004
m ii wrote:
>> well, both seemed to have forgotten any requirement for *cooling* air.
>> for this engine, that requirement is 2400 cfm...
i suppose that spec only applies in a small enclosure, with no other way
to remove the heat. a 12 kw generator might also make 12x4 = 48 kw of heat,
ie 164k btu/h, like 3 modest home furnaces. that would raise the temp of
a 2400 cfm airstream about 68 f, so the small enclosure might be 168 f
on a 100 f day... or are they saying the engine won't work outdoors, in
still air? :-) if outdoors is ok, how about grand central station, and
successively smaller enclosures...? in a large enough enclosure, the
generator needs no cooling air, since heat can dissipate by conduction
through the walls of the enclosure.
>...i'd be tempted to keep as much of the heat as possible in the garage,
>to avoid paying heating costs.
sure. small generators make 4-5 times more heat power than electrical power,
measured in the same units. why waste it?
>is the weather bad when these outages are most likely to happen? if so,
>keep the heat.
cogen (using the heat) can make economic sense even without an outage.
>if the heat is not needed, i'd box in the generator set and vent for the
and depressurize the enclosure, eg the garage, to keep co out of the house,
or depressurize a smaller box inside the garage, to keep co out of the garage.
a smaller box containing a 55 gallon water drum with the exhaust bubbling up
from a pipe full of holes might also have a fan blowing hot air on the engine,
something that keeps the fins as cool as they would be in still outdoor air
on a hot day, which may not be hard to do with hotter box air, since the fin
thermal conductance increases with airspeed (2+v/2 btu/h-f-ft^2 at v mph.)