When is it a good time to test the AC system on a house. In my area the night temps still drop below 50 degrees but the afternoons are getting aboue 75 degree. is the warm enought to run the system.

Recommend to test if the ambient temperature has been above 65 F for 24 hrs, otherwise run the heat cycle.

thanks, that was what I was thinking do just needed a second guess.

Run the furnace before you test the A/C. Get the heat up to give the a/c something to work on.

When you do your initial walk around the outside, shut down the outdoor breaker. After getting the heat up in the house, change to cooling mode. When you get back outdoors, turn on at the breaker and make your tests. Keep it short and just check that things are operating. Don’t try to pull down the indoor temp.

The reason for not running the a/c when it is cool is that: 1. There is not enough heat to “use up” the liquid refrigerant in the system and it may flood back to the compressor and damage the moving parts. 2. Refrigerant migrates to the oil in the compressor. When the unit starts the refrigerant is pumped and the oil with it. Then your running the unit w/o oil.

A/C equipment can run in cold weather with the proper modification. There are all kinds of applications where a/c is needed in the winter because of high indoor heat loads. It is not the cold, it’s the modification that is the issue. It is easy to modify a residential a/c temporally but you need an EPA Certification to do it.

A Heat Pump can run in heat or cool (as it does that all the time anyway) in winter. The suction line accumulator protects the compressor from refrigerant slugging mentioned above. Why run in cooling in the winter? To make sure that the reversing valve operates.

As I have posted before, be careful telling clients that “the reversing valve is the only difference with heat and cool modes on a heat pump”

This is just not true, many other parts can be bad and just affect one mode.
If a parts changer tech replaces the valve and then the control board or the thermostat etc. the bill for repairing one inoperative mode could be several hundred dollars.

My 4 year old, 14 seer carrier/bryant’s have a programming item that will keep the A/C off it is below 55 deg.

There are a lot of things that can not be tested in an off season. You should never report the unit as operational, but you can state what was tested.

You can tell them that the compressor ran, the reversing valve changed, the aux. heat came on. But you should also state that due to the seasonal weather, complete evaluation could not be performed.

If the temperature AT THE TIME OF THE INSPECTION is 65°F or higher, I run the air conditioning. Rarely, if ever, is it higher than 65°F for 24 hours in our mountain, desert, inland, and coastal areas here. Hmmmmmmmm. In other words, rarely is it 65°F for 24 hours in any of San Diego County. It gets real nice and cool here at night. Hmmmmmmm. This fact might allow me to never test the air conditioners, making for much shorter inspections and reports. Hmmmmm. I think I’m on to something.

Why do you have A/C there?
A whole house fan should do it.

Yea, for 345 days of the year.

The other 20 days we are subject to hot, dry Santa Ana winds coming out of Nevada. Maximum wind gusts since I moved here in 1993 have been 86 mph, and the high temperature was 113°F. That requires a heating AND cooling system.