Air Source Heat Pump?

evilstevie · Post by **evilstevie** » Sat. May. 10, 2014 1:06 am

We had a (free) energy audit last week, and the guy mentioned the possibility of an air source heat pump to supplement our propane and coal. These units apparently do not work so well below around 35F, but here in upstate NY there are plenty of days from Oct - Dec, and March - May, where temps are well above that but we still need heat, but typically do not run the coal stove. We currently do have central air and forced hot air ducting, so this potential heat pump would pretty much drop into place, and could be integrated pretty well with our existing propane furnace via a new thermostat.

Anybody have any experience with these units in NY or PA climates? I've read that they're a lot more common further down south....but not sure if the ROI really pans out here in upstate NY.

Thanks!

davidmcbeth3 · Post by **davidmcbeth3** » Sat. May. 10, 2014 1:30 am

I have one .. it works ... but I never use it with my stove running ...

Post by **Richard S.** » Sat. May. 10, 2014 2:26 am

You can use the calculator here to get a starting point, change the efficiency for electric to 280% (or whatever the unit is advertised as).

https://coalpail.com/fuel-comparison-calculator-home-heating

Keep in mind that 280% is under ideal conditions, e.g 55 to 60 degrees outside. As the temperature decreases the efficiency decreases. That's why they are popular in the South, they are in those temperature ranges that are most efficient.

Ed.A · Post by **Ed.A** » Sun. May. 11, 2014 8:23 am

Mine is part of my mini-split AC system. Works great for spring and fall when it's too early/late to hit the coal pile.

jpete · Post by **jpete** » Sun. May. 11, 2014 9:08 am

The "ductless split" heat pumps are more popular around here. On a 40* day, I routinely see ~125* discharge air coming from these units. They will heat large rooms or small houses pretty quickly at temperature.

McGiever · Post by **McGiever** » Sun. May. 11, 2014 9:23 am

Not all heat pumps are created equal...some are really quite good.

Ductless Mini Splits operate in the exact design configuration the mfg'r designed them to operate in.
Other type systems added on/into existing duct systems are hit or miss depending on ductwork design/layout...which is rarely optimum.

Heat Pumps are only as good as their installation/system can allow them to be...can't always condemn the unit itself.

Carbon12 · Post by **Carbon12** » Sun. May. 11, 2014 10:46 am

The $$$ you'd spend on the heat pump would buy a hell of a lot of coal,.....even a bunch of propain! Do you have central A/C already? If you do and it needs to be replaced, then and only then I'd go with the heat pump. If you don't have A/C and want it, go for the heat pump also.

revtim · Post by **revtim** » Fri. Aug. 22, 2014 10:54 am

Why not look into a geothermal heat pump setup? From the research I've done, they are much more efficient and provide significant savings on the cooling side as well. Plus, I'm not sure if this is the case everywhere but in Michigan, our electric utility will set up a separate electric meter for your geothermal heat pump and sell you electricity at half the going rate to power it and your hot water heater too.. assuming it's electric as well. Combined, that makes it a real bargain.... with the exception of the crazy high installation price.
That's the direction I'm headed once I get my coal stoves installed. In the end, I'll have a 3 ton geothermal heat pump plus two coal stoker stoves. The backup for the heat pump will be a forced air LP system that I intend to never run.. except for the fan to move the air. It may seem like overkill but I'm certain that without the coal stoves, the heat pump alone wouldn't keep my home toasty warm on really cold days without the LP kicking in and after this last winter in this old farm house as the Polar Vortex descended and my old LP furnace began dying... like Scarlet O'Hara I proclaimed... "I'm going to live through this and when it's all over, I'll never be chilly again. No, nor any of my folk. If I have to lie, steal, cheat or kill. As God is my witness, I'll never be chilly again."
PS: There are some pretty awesome tax credits and generous financing programs around for geothermal heat pumps too... which is another advantage.

windyhill4.2 · Post by **windyhill4.2** » Fri. Aug. 22, 2014 1:58 pm

LOTS of $$$$$$$$$$$$ at good interest rate + tax credits = STILL many $$$$$$$$$. LOTS of electric consumption at 1/2 price = STILL high operating costs. A brand new coal boiler,installed by a professional is still cheaper to install & operate than the geo-expensive unit. The coal boiler can easily make hot water too !

revtim · Post by **revtim** » Fri. Aug. 22, 2014 4:11 pm

windyhill4.2 wrote:LOTS of $$$$$$$$$$$$ at good interest rate + tax credits = STILL many $$$$$$$$$. LOTS of electric consumption at 1/2 price = STILL high operating costs. A brand new coal boiler,installed by a professional is still cheaper to install & operate than the geo-expensive unit. The coal boiler can easily make hot water too !

True... but the geo-expensive unit can also cool the house in summer, something coal can't do, for a fraction of any other method of cooling except for soaking my t-shirt in cold water then standing in front of a fan... I can live without A/C as this ain't Phoenix but since I don't want to, I don't have to and the savings of geo over air heat pump for cooling alone will pay for itself over time.

windyhill4.2 · Post by **windyhill4.2** » Fri. Aug. 22, 2014 5:21 pm

OVER time >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

McGiever · Post by **McGiever** » Fri. Aug. 22, 2014 5:27 pm

There are previous threads with lively discussion on the Geo-thermal heat pumps or sometimes they're called ground source heat pumps.
No need to re-hash it all here again.

Scottaw · Post by **Scottaw** » Tue. Nov. 25, 2014 11:42 am

I run two air to air mini splits with my coal and it works great.

First, their fans help push the coal heat around, even if their heat never kicks on.

I ran a winter with just them in central pa and stayed warm, not as warm as coal, but acceptable.

And they dehumidify and AC in the summer. Pretty awesome
Combo all around.

Mikeeg02 · Post by **Mikeeg02** » Fri. Nov. 28, 2014 8:41 am

When I bought my house, I put in central air. It first came with oil hot water heat. The difference between AC and a heat pump compressor is literally less than $200. So I put in the heat pump. Works fantastic, and will keep the house at 74 until 30* outdoor. The heat pump IMO is more efficient above 40* outdoor, and it requires no user intervention, and is not anything near what oil costs to run. So until it's constantly below 40 during the day, that's what heats, even now that I have my coal boiler setup.

To change an A/C type system to a heat pump type should only require a new outdoor unit, a thermostatic expansion valve (TEV), a little pipe soldering, thermostat wiring, and a system charge.

This is all assuming you can get one with the same refrigerant as what you have currently. If you have to get the newer r410a, you typically need to change out line sets, and the A coil in the air handler as well.

McGeiver is right, the most efficient ones are the ductless, but any modern heat pump compressor is pretty good. Mine has a 13 seer rating and a marginal HSPF rating, which is the number you want for heating performance. (Heating Season Performance Factor). The seer rating is for cooling.