[RFI] RF quiet HVAC

[charlie at thegallos.com]

> You need to be in a warmer climate for heat pumps to work efficiently. I
> have several units and my main floor one also has a propane furnace that
> takes over when it is less than 30 degrees outside.  I have noticed no RFI
> with any of my American Standard heat pumps.
>
> John KK9A

Yes, a lot of people don't think about it, but let's say you like your
house at 70 degs F - a HOT day, of 100 F has a temp delta of 30 degs, and
MOST HVAC systems actually have problems keeping up with that, and might
not actually be able to keep you at 70, but might bring it to 74 or so -
but let's say it can maintain 70.  That's about what systems are sized for

Now it is winter, and you still want to maintain 70 degs.  A 30 deg delta
in temp is 40 degrees.  Any COLDER than that, you have to start over
sizing your heat pump.  Want it to work at zero F? Yep, you need a 70 temp
delta, more than twice as much BTU wise (and it is harder to make those
BTUs)

Heat pumps work best where the two sides of the desired temperature are
roughly the same - figure NC Shore and south, along the south, and up the
west coast.  Most heat pumps are available with aux heater coils, but then
you have that additional cost to run