[form8829]

this is for a heat pump and a honeywell thermostat model: TH5220D

Second stage heat
cycle rate/
Auxiliary heat
(CPH)
5 - For gas or oil furnaces of less than 90% efficiency
1 - For steam or gravity systems
3 - For hot water systems & furnaces of over 90% efficiency
9 - For electric furnaces [Other cycle rate options: 2, 4, 6, 7, 8, 10, 11 or 12 CPH]

 

[Bob Sanders]

I now use a cph of one for the Hp and 2 for the aux heat. I don't like a lot of cycling.... it drives me crazy

 

[supers05]

Single stage heat pump? Electric aux heat? I would put it at 4-5, higher would be more comfortable, lower would let the compressor run longer before cycling the expensive aux heat back on.

Cheers!

 

[user_12345a]

3 is good.

 

[beenthere]

Don't set electric aux heat CPH higher then 3.

 

[Bob Sanders]

I would put it at 4-5, higher would be more comfortable, !

Maybe it's just me but I don't notice a stick of difference in comfort between 1 and 4 (haven't tried anything higher). All feels the same to me. Just more cycling at the higher numbers.

 

[form8829]

thanks for your reply Bob. this is 2 stage heat and 1 cool

 

[Bob Sanders]

thanks for your reply Bob. this is 2 stage heat and 1 cool

I have:
stage one compressor heat/cool CPH 1
stage two compressor heat/cool CPH 1
stage one electric back up heat CPH 2
stage two electric back up heat CPH 2

I have played with it all up to CPH 4, and I really don't notice any difference comfort wise (My wife doesn't either), just an increase in cycling. I think the short cycles for a HP really don't do a whole lot other than waste energy. I have found it can take up to 5 minutes for a heat pump to settle out at proper pressure and start pumping usable heat, so at 4 cycles an hour, that's pretty much 20 minutes of wasted energy.

 

[supers05]

I have:
stage one compressor heat/cool CPH 1
stage two compressor heat/cool CPH 1
stage one electric back up heat CPH 2
stage two electric back up heat CPH 2

I have played with it all up to CPH 4, and I really don't notice any difference comfort wise (My wife doesn't either), just an increase in cycling. I think the short cycles for a HP really don't do a whole lot other than waste energy. I have found it can take up to 5 minutes for a heat pump to settle out at proper pressure and start pumping usable heat, so at 4 cycles an hour, that's pretty much 20 minutes of wasted energy.

You notice it more when it's fairly hot or cold outside. Less when it's mild out. Fuel furnaces also make it more noticeable with their high heat output. Heat pumps even things out more.

Cheers!

 

[beenthere]

I now use a cph of one for the Hp and 2 for the aux heat. I don't like a lot of cycling.... it drives me crazy

Thats your duct work not being big enough that makes you notice it.

I have a lot of York 2 stage heat pumps in, that the home owners can't tell when it cycles from stage 1 to stage 2, or back. They only know when its using the aux heat, because the air temp becomes warmer.

The close the duct TESP is to .5" or less, the quieter the system is.

 

[Bob Sanders]

Thats your duct work not being big enough that makes you notice it.

I have a lot of York 2 stage heat pumps in, that the home owners can't tell when it cycles from stage 1 to stage 2, or back.

To a certain extent I would agree. I enlarged the duct work as much as I could but it's still just a touch too small.

The other side of the coin though is you can hear the fan kick into high gear as it goes from stage one to two. That you would hear regardless of duct work size.

 

[supers05]

To a certain extent I would agree. I enlarged the duct work as much as I could but it's still just a touch too small.

The other side of the coin though is you can hear the fan kick into high gear as it goes from stage one to two. That you would hear regardless of duct work size.

With a smooth ramp, like ecms give, it's actually quite difficult to hear.

Cheers!

 

[beenthere]

To a certain extent I would agree. I enlarged the duct work as much as I could but it's still just a touch too small.

The other side of the coin though is you can hear the fan kick into high gear as it goes from stage one to two. That you would hear regardless of duct work size.

No, properly sized you don't hear the fan when it goes from first stage to second stage.

I put in a lot of 2 stage A/Cs, heat pumps and gas furnaces. If they can be heard(excluding if the equipment is in a closet in the living area) going to second stage, the duct work is too small, and the size and amount of supplies are too small and not enough.

Measure your TESP, you see how under sized your duct system is.