On Fri, Jul 30, 2010 at 4:58 PM, Randall <tr3driver@ca.rr.com> wrote:
>> Anyone know much about current HVAC? B The heat pup at our
>> "shop" B [ok - it's really the office] has a bum compressor in
>> the outside unit, and the unit is mis-matched. B It's 1.5 ton,
>> and the inside air handler and coil are 2.0- ton. B seems like
>> a whole new outside unit would be the way to go.
>
> Why? B Using an oversize evaporator & air handler should not be a problem,
> and will actually be slightly more efficient overall. B Of course you'll
only
> get 1.5 tons of cooling, so the real question is whether that is enough for
> your situation. B Think of it as a 45hp motor in your VW bug, instead of a
60
> <G>
>
>> B He says replacement
>> compressors are available, but the age and condition of the
>> unit makes this inadvisable.
>
> Again, why? B Basically everything that wears out (compressor, fan, etc)
can
> be replaced. B Unless the coils are damaged, you should be able to keep it
> going nearly forever.
Manufacture of service parts stopped 31 Dec, 2009. If the indoor coil
is an old, low efficiency model, attaching it to a modern (well,
moderner, but already obsolete) high-efficiency compressor will result
in *lower capacity and efficiency* than if it were the old
low-efficiency compressor. So, even if he were to buy a SEER 14 R22
unit for the outside, if the evaporator is still a SEER 10 unit, the
system efficiency would be somewhere around 8. Depending on where you
live, the building, and the electric rate, that could cost a couple
thousand bucks a year, though a few hundred is more likely. If that's
not enough, the actual capacity of the system is reduced by about 40%
as well.
So, even if R22 weren't a dead end, it might well make sense to
replace the whole system. And if you're replacing the whole system,
there's no reason to use R22, unless they give you the equipment for
free.
--
David Scheidt
dmscheidt@gmail.com
_______________________________________________
Shop-talk@autox.team.net
Donate: http://www.team.net/donate.html
Suggested annual donation $12.96
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
|