Does Anyone using a Robert Shaw 9865i or a 9615i??

[rickytz7111]

I was just wanting to know if anyone was using this stat. I spoke with my installers and I told them I think this stat might do the job of cutting out the short cycling. He recommeneded that we try and find a white rogers that had a adjustable differintial. They do have one but it's only 1.6 degrees where the shaw is 3 degrees. However it does seem that my run time have gotten a little better at night. It is still like 89 degrees here. Thanks

[amd]

You should also consider a honeywell t-stat with an adjustable cycles per hour setting.

CPH based t-stats are intelligent in the sense that the differential is determined based on the system operating conditions and maximum cycles per hour parameter.

During cooler, humid weather a differential of 3F could mean having the system off for several hours at a time or not run at all. (Result - heat stratification, uneven temps, high humidity)

[beenthere]

Remember, no matter what stat you try, this is a bandaid repair for an oversized system.

[rickytz7111]

beenthere,

The boss of the AC company will be in monday. They were going to check the heat load when he gets back. So does that mean they only did a heat load? Have you heard of them doing that before without doing a cooling load? If it does call for a 4 ton heat system and a 3.5 ton cooling system what are my options? Have them take out the 4 ton system and have them only replace the AC part of the system with a 3.5 ton? Will they be able to replace just the outside unit or will they have to get into the attic to put some stuff in? Thanks again for all your knowledge.

[beenthere]

They may have sized it to the heat load. Some companies do that to save you money on your heating bill.

Although the Manual J load calc allows you to oversize by 25% for a heat pump.
What happens some times. Is the house comes out to 3.15 tons for coolingWhich would normally mean a 3.5 ton A/C. But they still put the 4 ton in for heating. And thats when this type of thing can happen.