On 1/20/2013 9:06 AM, NotMe wrote:
Home pre-sale inspections cannot be run for the A/C side if the outside air
temp is below 60F.

New to me and I'm curious why this might be so?

TIA


At low outside temperatures an AC system can't build up enough head
pressure to operate properly and get any meaningful performance
measurements from. When I have a customer who owns a restaurant or other
type of business where the AC may be run year-round, I install
a head pressure control or condenser fan switch. The fan switch keeps
the condenser fan off until the high side pressure gets high enough
for the system to operate without causing damage to the compressor.
The on off pressure switch is the simplest but crude for controlling
head pressure which is why I prefer a variable speed fan control which
provides a more consistent level of performance. The most inexpensive
residential AC systems lack a factory installed head pressure control
which is why it's not prudent to run them in cold weather. ^_^

https://www.youtube.com/watch?v=sR6-ccP5KdI

http://www.hoffmancontrols.com/pages/816-10DH.htm

TDD