Carrier makes a great heat pump depending on model quoted. I prefer Trane or sister company AmStandard because of electronic demand defrost which is a feature you would want. Carrier HPs do not offer that feature which is a big negative.

IMO

$7 K for a 4 ton XL18i HP condenser with TAM7 air handler?

Post all model numbers.

Excellent price.

What thermostat?

What size heat strip?

What size system are you replacing?

Post back...

IMO

"I also like carrier since it has a lifetime warranty on the compressor"

Are you sure you would get a lifetime warranty?

Mike is correct. Carrier does not have a lifetime warranty on their compressors.

TD

As far as heating goes electronic demand defrost has to be one of the largest savings on my upgraded system. On the cooling side the TXV metering rather than piston orifice allows lower humidity which makes a warmer temp comfy.

Trane american standard, rheem/ruud are just a few that have these options.

countryboymo,

"electronic demand defrost has to be one of the largest savings on my upgraded system."

I would be very interested in how you determined this to be the case. With my Carrier system the amount of electricity and the amount of oil used during defrost would seem to very minor.

Additionally, the energy usage during defrost as well as the manner of defrosting timing is included in the computer model that predicts system efficiencies.

Thanks in advance.

This post was edited by saltidawg on Fri, May 2, 14 at 8:01

Hey Salti,

Bad enough to temper AC with heat strip but how bout the oil usage?

Putting aside the cost savings which might be difficult to measure, how bout all those unnecessary defrost calls switching back and forth frequently that add wear and tear to the condenser in particular the reversing valve?

I would expect this cheap time/temp defrost method from Goodman Pumps but very surprised Carrier does not have EDD on their pumps particular the upper end models.

TD

This post was edited by tigerdunes on Fri, May 2, 14 at 8:44

tiger,

Just questioned the statement about savings. Wear and tear issues I have no way of assessing.

My oil usage during defrost is absolutely miniscule in cost... I don't know how to determine the electrical cost during defrost, however it is my firm belief that it is pretty small compared to the electrical usage for heating. (And in any event, the defrost electrical usage is accounted for in the model used for calculating efficiency so as to allow comparisons of different units.)

I can assure you that wear and tear is definitely a factor. Many HVAC pros think EDD is not a big issue. Others like me think it is.

IMO

And again, I was asking about the energy saving assertion.... "largest savings on my upgraded system."

As you know, I am not a HVAC Pro... just a homeowner. I defer to your statement that wear and tear is definitely a factor. Not one that I personally would consider, however, based on many years of operating equipment on an intermittent basis, including industrial heating and cooling equipments.

This post was edited by saltidawg on Fri, May 2, 14 at 13:02

If one eliminates or reduces unnecessary defrost calls, I would say you are saving backup energy costs that are necessary to temper the incoming AC whether source is electric or fossil fuel. I have never been told or read from an authoritative source that defrost calls were factored in AHRI HP Directory performance/efficiency numbers. Don't see how they could be.

But there is no doubt that two similar sized and configured systems placed in neighboring homes, one with time/temp and the other with EDD would have vastly different number of defrost calls.

Most homeowners are simply not educated on this feature. That's why I always point it out whenever appropriate and will continue to do so.

Time/temp is simply a cheap feature.

IMO

This post was edited by tigerdunes on Fri, May 2, 14 at 15:01

I'll see if I can find it (again), but there is a paper on-line discussing the parameters in the algorithm used in the AHRI method of predicting system performance... EDD is definitely an input.

In months where I am not using any oil except when heating during defrosts, I can not see any change in my oil tank level over a month or two time period... and whatever cumulative amount of oil that is used during say 10- 15 minute defrosts would be lessened if there were fewer defrost cycles, but the question would be what is THAT difference.

I would be interested in hearing from you in the trade what the most common methods of system failure are.

Specifically with a focus on what components fail due to increased "wear and tear" due to timed defrost?

From reading posts here it seems that mostly non-repairable refrigerant leaks leads the reported list followed by compressor failure... I believe most compressors carry a 10 year replacement warranty????

If I compare the operational wear and tear due to starting and stopping between an oil furnace and a heat pump in heating mode, the oil furnace cycles on and off much more frequently than the heat pump. Yet, my oil furnaces have typically lasted 30-40 years.

Just thinking out loud.