Heat Pump comments

I live in an area that rarely gets any lasting snow (lasting usually until afternoon and occasionally a few days). I have a forced air furnace that is ready to be replaced and I want to also upgrade to AC. Financially the heat pump makes the most sense as it costs little more than AC and I don't have to pay full price for a furnace then. I have heard comments both good and bad about heat pumps. For those of you who have heat pumps, what is your experience?

Mike D.

Reply to
Mike Dobony
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if you can buy electricity at a good rate a heat pump can be very economical to operate....but it becomes less effective when the temp is below freezing, the outside coil can ice up and it needs to go through a defrost cycle, for this reason most hp systems in cold climates have another form of heat as a backup.

A HP worked great for me in Phoenix AZ where it rarely went below freezing. What climate are yo in? Go to someones house in your area that has HP. also the air comming out of the vents is not as warm as with a oil or gas furnace. Some people don't like that.

Mark

Reply to
Mark

I'm in E TN and use a heat pump, but did NOT install the resistive emergency heaters. If I need a bit of extra heat I turn on al,the lights; if the temp really drops I start the wood stove. I heated using wood (& solar) for 20 years so a couple of fires per winter is no bother ;)

Free men own guns - www(dot)geocities(dot)com/CapitolHill/5357/

Reply to
nick hull

The resistive emergency heater woudl be necessary here, but the temps rarely stays below freezing durign the day ( a handful of days a year). They are common in new homes in the area, even more expensive homes.

Reply to
Mike Dobony

I would always suggest that if you are going to live there for more than 5 yrs or so, get a 95% gas furnace and a heat pump as a back up instead of just a normal A/C. This gives you the ability to use both fuels as you like according to the cost of natural gas and electricity. Your area needs to be able to support the heat pump so dont get one if you regularly have temps at 0 and below. I live in an area where the design temp is 6 degrees. At 15 degrees my heat pump stat shuts off the heat pump and its all gas then. Your local hvac dealer should be able to give you all the options. Bubba

Reply to
Bubba

"86 to '89 I had a heat pump ( North Florida Panhandle ), not far from the coastline. It seldom snowed, but was cold and did freeze now and then. The warm Gulf breeze help too reduce serious freeze.

Never had a single problem with that system in three years.

Reply to
Oren

I had a heat pump for heating domestic water. Efficient and saved $$. Down side was that it also chilled basement air, sometimes too much.

Heat pumps are the way to go for heat and water. Anything to get off fossil fuels. Check around in your area to see how effective they are for you.

Reply to
franz frippl

Fairly common here, even in $200,000 new homes.

Reply to
Mike Dobony

eatpumpmakes the most sense as it costs little more than AC and I don't have=

I think this is a great question and you should know more about what you are getting into before signing up for the heat pump.

I live in northern Colorado, and it's likely my situation is similar to yours. We get snow, but many years it doesn't last. Days are generally warm (30's to 50's or higher are common during the winter) but nights get cold (20's or lower). Our local electricity coop offered a rebate for heat pumps, and I was wanting A/C for the hot summer evenings, so I took the bait. I also wanted to get away from fossil fuels. We still needed a furnace for backup, but went with 95% efficient gas unit at 90,000btu

Does the heat pump work? If it's installed correctly it should work with the outside temp in the correct range. You have to be prepared for it not being anything like a furnace. It's much more like running a warm A/C during the winter. We got a 3 ton unit for heating approximately 2000 sqft (at the very best, the manufacturer claims

32,000 BTU heating). Heat pumps work more efficiently at higher temperatures and your contactor should be able to provide you with a breakeven temperature at which it becomes cheaper to run the HP than a furnace. With the electricity and gas prices we have, and the efficiency of our furnace and HP, the breakeven for us is around 35f. It only makes sense to run the HP if the outside temperature is above 35f. For us this is usually during the day and at 35f the sun usually is enough to heat the house.

So, what is the HP like? It runs a lot, its noisy, and the air coming out of the register is cool. Like A/C, it's best to think of how much heat the HP will add to the cold air running though your ducts. In our case, the HP warms the air up by around 15f compared to over 50f for the furnace. This means that if the house is at 70f, the heat coming out of the registers is 85f. This is cool on a cold day. By the time the air reaches a few feet from the register, it's 70f air blowing across you. If you set the temperature back at night, like we do, you could be looking at 60f + 15f =3D 75f air at the registers and the air moving across you is cold. Also, it's very slow to change the temperature in the house. In the morning, our house would warm up at less than 1f per hour. This really makes a setback at night impractical.

The noise from the heat pump can also be something entirely different from what you are used to. You now have loud machinery operating outside your window day and night. In our case there also a random loud gurgling noise when the compressor switched over to defrost (which can happen even when it's fairly warm outside due to the coils running substantial colder then the ambient air, they almost always become coated with frozen condensation). The frequency of the noise penetrates right through concrete making even the basement noisy.

HP are also much more complex than furnaces. It took nearly a year to get reasonable efficiency out of our HP and I'm still not convinced we aren't throwing a lot of money down the drain. In our case, for many months, the air in the registers was only being heat by 5 degrees. After a very frustrating exchange over several months, my HVAC contactor contacted the factory and were told to replace the thermal expansion valve. This got me back to the 15f, but it was not easy to understand that 1)there was a problem 2)it could be fixed 3)find the source of the problem.

If you can live with the issues mentioned above, the HP can keep your house warm. I've thought that running the house at a higher tempurature, say 74f, would make the cool breezes issuing from the registers less of an issue because the house would simply be hot.

Would I do this again? As much I wanted this to work. As much as I like the technology and want to save green house gases. NO. I would not do this again. We can only run the HP a few weeks during the year, and it doesn't seem justified. I don't expect it ever to pay back financially and it's not a comfortable way to heat. Our electicity bills have been higher than ever and I'm not convinced that our total energy costs are lower (I may be able to piece this together in a couple more years).

I should add that geothermal heat pumps are a whole different animal. They are very expensive, but if installed properly I believe they would be very efficient and useful down to colder outside temperatures (although still noisy).

Reply to
alan.b2

snipped-for-privacy@live.com wrote: ...

Yes

No. The removal of the air source to the recirc fluid pump makes all the difference in the world. It's the air exchanger that's the noisy component and it goes away.

I clipped a bunch for brevity, but I'd disagree on the assessment of suitability based on amount of snow and how long it stays around. It's the temperatures and the temperature profiles that matter, not the amount of precipitation and/or its form. One doesn't necessarily imply the other. It's colder than blazes here a lot of the time, but it snows almost never when it is cold and annual snowfall can be from none to feet, just depending on the year. Need a qualified installation calculation to judge.

Reply to
dpb

Well, there's quiet, and then there is quiet. Truthfully, I don't have a geothermal HP (do you?) and have never seen one. I have heard, which makes this second hand, that they can sound like an elevator motor (whatever that sounds like). Based on my experience, I would recommend witnessing a live, operating HP in your neighborhood to anyone considering an installation. You, and your installer, will be happy you did.

Sure, all I'm relating is my personal experience and using the information offered by the original poster to draw comparisons, it's all I've got.

Reply to
alan.b2

I may be mis reading what was in your great message, but, why not use the furnace to warm the house in the morning, then shift to heat pump once the house makes it to the desired temp, assuming the outside temp permits. Many, many years ago I bought this house which had hot-water baseboard heat, no A/C. I added A/C. 4 years ago when replacing the A/C i shifted to H.P. since the additional cost was minimal, and I'm a fan of redundancy. I turn all heat off at night. If interior temp really drops, I use the boiler to bring the heat up, then shift to the H.P. I rationalize this (with no facts to back it up) that the short use of the fossil fuel, is offset by the decreased use of electricity for the longer period required to reach the same temp. I do find that even with the installed variable speed air handler, that the full bore H.P. operation required to warm things up in the morning can be noisy. However, once there, and the same with the A/C in the summer, I can't even tell it is running.

Reply to
Roy Starrin

....

Yes, I had one for several years. It was virtually inaudible running over the typical fan air movement noise. As compared to an air-exchange unit or even a typical A/C exchanger it was what I would classify as silent. (Moved is reason for the "had" -- am looking at replacement furnace now and ground-loop is certainly in the consideration).

And, your complaint of the air/air exchange heat pump goes away -- the air at the outlet feels nice and toasty -- not quite natural gas hot, but no "wind chill" factor at all. (The loop in the TN house replaced an air exchange unit so I have that to compare to by direct experience, too.)

Reply to
dpb

You and Roy have both made insightful comments. I have heard that if the working parts of a geothermal unit can be remoted from the house, the house will indeed stay quiet. Personally, the loudest thing I want to hear in my home is the fridge, and only because I know it's keeping my beer cold. Which brings me back to Roy's input. My contactor finally installed an upgraded Honeywell thermostat that is supposed to fire up the furnace if the temperature error in the house is too large. Like Roy, this should give me a comfortable recovery in the morning as well as reducing the consistent noise. I haven't gotten this new option fully dialed in yet, and now it's the dead of winter.

I left out some details in my original post, which could be important to this discussion, but I felt the post was already exceeding a rational length. My outdoor compressor is a long way from the indoor coil. It's over 50 feet away. To maintain efficiency my contactor tried using a large diameter, I think it's 1-1/8 suction line. I find that it takes nearly twenty minutes of HP running to fully heat up the piping. It never really heats up with cycling. It's hard for me to see how this can be efficient and I have to believe that it leaves the register air cooler than a short run pipe might (say under 15 feet). Like I said, these systems are much less straight forward than a simple 95% furnace, and way-way more complex than the old 70% furnace.

I also forgot to add that I might feel better about the heat pump, it's cool register temperature, noise, and slow recovery; if I was burdened with the large cost of straight electric resistive heat.

Reply to
alan.b2

There was nothing "remote" in our installation -- the recirc pump/exchanger is no more noisy than a typical fridge compressor. It simply wasn't a noticeable noise over if it had been forced air natural gas.

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Reply to
dpb

Is that 1 1/8 line insulated? Obviously t will not get hot at the indoor coil instantly, but should be pretty warm after a couple of minutes-- much less that 20- unless you are talking about really low OD temps.

Reply to
lp13-30

It is insulated with Armaflex insulation, and does begin warming up reasonably quickly. It's just very slow to reach a stable temperature at the inside coil. The final temperature is generally over 20 degrees cooler than right at the HP compressor.

Reply to
alan.b2

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