A/C/ Heat Pump questions

[Kenneth Brown]

Lets say you have a A/C unit thats rated as a 13 seer. Lets say you also have a A/C heat pump unit thats 13 seer. What would the operating difference be cost wise? The difference in price is only about $225 in the unit price. This is for a 2 ton unit of which I will need 2, one upstairs and one down. Is it worth it to get a heat pump? How long generally would it take to recover the cost?This is one area I haven't looked into much so any help is appreciated, I'm a dummy in this department, I know just enough to get me in trouble .

 

[ob]

Re: A/C/ Heat Pump questions

There is no difference in the efficiency of a heat pump verses a conventional system in the cool mode as it operates identically.In the heat mode at ambient temps above 35 F the energy consumption difference is marginally in favor of the heat pump.Below 35F it may even consume slightly more.Heat pumps use electric crankcase heaters for the compressor in the heat mode as well as supplimentary heat strip/s to compensate in the heat mode.Also consider that the run time of the compressor is significantly higher through the seasons with a heat pump thereby decreasing its life as compared to a conventional sysytem.I guess you can tell I'm not a big fan of heat pumps.Perhaps that's why they are not as widely used as conventional systems.

 

[Kenneth Brown]

Re: A/C/ Heat Pump questions

OK, any other opinions?

 

[ED21]

Re: A/C/ Heat Pump questions

How are you going to heat if not with the heat pump?
A gas or oil furnace is a lot more than $500, but you will still need an air handler for the a/c or heat pump. The typical way to have backup heat with a heat pump is to put electric resistance coils in the air handler. Backup heat is needed when the temperature drops below about 32 degrees or if it craps out.
It's usually thought heat pumps are a little more robust since they are designed to run more, but I wouldn't buy a heat pump if a/c is all I needed.
If you already have a furnace that uses gas or oil, I'd stick with that unless there's a reason to change.

 

[rickdb1boat]

Re: A/C/ Heat Pump questions

Agree with OB. If you already have a heating source (Gas, Oil, Electric), then go with the plain A/C units. As he said, heat pumps will run darn near year round and are far more complicated than the typical A/C unit. Not to mention you will need new thermostats and wiring between the Stat, Air Handler and Heat pump unit. I really avoid selling Heat Pumps here in the Midwest, as they tend to be more trouble for the service department and are not a big savings to customers in the long run in this climate...

 

[Kenneth Brown]

Re: A/C/ Heat Pump questions

The system is a new install, here in central Texas. The prices are correct, except I didn't add the heat strip for the non h/p unit. I currently have studs and joists and wondering which way to go.

 

[Kenneth Brown]

Re: A/C/ Heat Pump questions

Surely somebody else has an opinion, or can add more now that you have more info to go on...........

 

[tomatolord]

Re: A/C/ Heat Pump questions

The efficiency of air conditioners are often, but not always, rated by the Seasonal Energy Efficiency Ratio (SEER). The higher the SEER rating, the more energy efficient is the air conditioner. The SEER rating is the Btu of cooling output during a simulated, typical cooling-season divided by the total electric energy input in watt-hours (W·h) during the same period. [1]

SEER = BTU ÷ W·h
For example, a 5000 Btu/h air-conditioning unit, with a SEER of 10, operating for a total of 1000 hours during an annual cooling season (e.g., 8 hours per day for 125 days) would provide an annual total cooling output of:

5000 Btu/h × 1000 h = 5,000,000 Btu
With a SEER of 10, the an annual electrical energy usage would be about:

5,000,000 Btu ÷ 10 = 500,000 W·h
This is equivalent to an average power usage during the cooling season of:

500,000 W·h ÷ 1000 h = 500 W
The average power usage may also be calculated more simply by:

Average power = (Btu/h) ÷ (SEER, Btu/W·h) = 5000 ÷ 10 = 500 W

from wikipedia

I have a heat pump but with a gas backup, when the temp goes below 40 the gas heat kicks in

What you need to do is put a thermostat on the heat pump, about 35 degrees and set it to 40 or degrees then when it goes below this temperture it kicks on your regular heat,

if you go with the strict heat pump vs no back up heat do the thermostat again becuase then what happens is the auxilary heat will not kick unless it is below that outside temp as well.

Father in law has only a heat pump in st louis, and I am pretty sure his heat pump ran for 6 hours straight in the winter, took 15 minutes off and started running again.

My heat pump with this setting does not run very often maybe 4-5 times a year in this mode, becuase you have to think about how many times it is above 40 degrees for any period of time where you need the heat on.

225 might take quite awhile to recover

tomatolord

 

[stevieray]

Re: A/C/ Heat Pump questions

Did you look at a geothermal heat pump? I put one in the new house I built here in MD 3 yrs ago & I wouldn't have anything else. Up front cost is higher than A/C with oil or gas for heat because you need to drill a well or 2 depending on min/max ambient temps, but fuel cost is no issue - just the electricity to run the pumps & compressor (very low consumption).

 

[Kenneth Brown]

Re: A/C/ Heat Pump questions

Actually I have looked into it a little. Most of the cost comparisions I hvae seen say that the cost realtion isn't until almost 20 years and that is considered the life of the system. If I had a pond close to the house (heck I wish I had a pond at all) the cost would go way down. As with every big project some of the finer things we wanted are gonna have to wait or just get scrapped period. A solor water heater on the back roof and a geothermal ac/heat system would be real nice but the initial costs are gonna rule them out. Out of curiousity would you mind saying what your system cost?

 

[stevieray]

Re: A/C/ Heat Pump questions

House is 3000 sq ft. Hardware & installation was roughly 11K. I had one "dry" well on the property that could be used, so I only needed to have one more drilled to 250ft so that was another 4K. I figure my payback will be about 10 yrs what with today's price of oil (which was my only other fuel option). It is far different from the older heat pumps that basically blew cool air around the house all day & called that heat. Plenum air temp from this is over 100 F so it runs a lot less & feels better. The A/C will freeze you right out. Also has a built-in heat exchanger on the desuperheater side hooked up to my water heater, so I basically get free hot water whenever the system is running.