Heat Pump vs Furnace/AC

[ngbjr]

Hello all,

We are looking at the purchase of a house that is currently heated with a propane gas furnace. We live just a little north of Atlanta, so generally the climate is pretty mild. I am thinking it may be a better long term solution to switch to a heat pump(s) given the cost of gas and minimizing the need to refill the gas supply. The house is newer (2003), roughly 4600 square feet and fairly well insulated (as far as I have been able to inspect). What is the general wisdom on this sort of change given current heat pump technology, or should I spend some time with the current system before looking into this? Thanks!

Norm

[tigerdunes]

As everyone who knows Hotlanta area/climate, it has hot summers and normally mild winters with a few short wintry blasts coming up from Bama.

If you don't have access to nat gas service, I would get rid of propane heat and go all electric high eff HP with var speed air handler and backup/supplemental strip heat.

Post your electric rate and propane cost and I will make a fuel comparison.

IMO

[motoguy128]

As everyone who knows Hotlanta area/climate, it has hot summers and normally mild winters with a few short wintry blasts coming up from Bama.

If you don't have access to nat gas service, I would get rid of propane heat and go all electric high eff HP with var speed air handler and backup/supplemental strip heat.

Post your electric rate and propane cost and I will make a fuel comparison.

IMO

It funny, I know they call it "hotlanta". But the actual design temperatures according to here: http://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/Outdoor_Design_Conditions_508.pdf (http://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/Outdoor_Design_Conditions_508.pdf)

Actually has it a little cooler and less humid then where I am on the Missouri border.

But I do agree that there's no winter there. :) A furnace in Atlanta would be about almost 1/3 smaller than one where I am. The desing temp isnt; even above freezing. But the AC would be about the same size. It would just run a lot more year round since it stays hotter in the spring and fall.

One thing to remember about being further south. The peak sunlight in summer is actually less than northern climates. But its' much more the rest of the year, especially in winter.


I agree, that looking at a heat pump would be a smart move. It will be cheaper to operate on all but the days that are well below design temp. The only question in my mid is whether or not you want dual fuel or heat strips. Heat strips will require a new 220 electrical circuit pulled. WHile you already have the gas to a furnace.

[ngbjr]

Thanks! I've only just started pricing propane so I don't have a lot of data points on that. The one solid price I have been quoted is $2.19/gallon (before any volume or term discounts). As for electricity we are paying roughly $0.120 per kwH where I am today (about 15 miles south of the house we are looking at). I will need to continue to purchase propane for the cooking but everything else looks to be electric, including the water heaters (which I am also considering replacing with on-demand heaters at some point).

Norm

[vstech]

if it were my house, and there was nothing wrong with the current furnace, I'd keep it, and remove the a/c and install a quality Heat pump, with a dual fuel thermostat. that way on all but the coldest days the heat pump would maintain the temps, and I would not need to run a new circuit to the air handler for strips!

jm.02~

[t527ed]

if it were my house, and there was nothing wrong with the current furnace, I'd keep it, and remove the a/c and install a quality Heat pump, with a dual fuel thermostat. that way on all but the coldest days the heat pump would maintain the temps, and I would not need to run a new circuit to the air handler for strips!

jm.02~

:ditto:

[ngbjr]

I had not considered a dual fuel option. That's very helpful. Hmmm....

Norm

[catmanacman]

if it were my house, and there was nothing wrong with the current furnace, I'd keep it, and remove the a/c and install a quality Heat pump, with a dual fuel thermostat. that way on all but the coldest days the heat pump would maintain the temps, and I would not need to run a new circuit to the air handler for strips!

jm.02~

Me x 3

[tigerdunes]

Here are the numbers using your fuel costs.

COP 2.75 and 80% eff furnace

Cost per 100,000 btu of useable heat

Electric baseboard: $3.16
Heat pump: $1.28
Propane: $2.99


COP 2.75 and 95% eff furnace

Cost per 100,000 btu of useable heat

Electric baseboard: $3.16
Heat pump: $1.28
Propane: $2.52

These numbers are to be used as a guide only.

IMO

[ngbjr]

Thank you very much. It's obvious that a heat pump is the most economical way to go, and it looks like that would be true even with some discounts on the base propane costs that I currently have quotes on. Are there any recommendations on brands and sizes of the most effective and efficient heat pumps to consider?

Norm

[tigerdunes]

ngbjr

How many systems do you have now?

Size and mdl numbers of AC and furnace would be helpful.

I would not purchase this home without first having an inspection performed by an HVAC pro. Get his opinion on what's there now and his opinion about HPs.

IMO

[ngbjr]

Thanks. I think that is good advice. I don't have all the details yet on the systems that are in place today. I do intend to have a thorough inspection done on everything prior to finalizing any purchase.

Norm

[energy_rater_La]

x4 on dual fuel.

I just installed a 15 seer heat pump where I previously
had propane heat.
propane costs are higher in the winter than summer..fyi.
I still have gas stove & water heater.

you might want to compare the cost of heat pump water
heater vs propane on demand.

best of luck.