Building a house

[gypsy]

We are having a house built and have been looking at using a heat pump to heat and cool. This is something pretty new to me and wondering if others who live in collder climates use heat pumps and what do you think?

gypsy

 

[luvtoride]

Heat pump (for the heat part) = electrically heated & forced air... I do believe. Never had one myself... but hear that they suck at the coldest times of the year. Also, heat pumps blow cool/tempid air.

I myself have a gas pack... heat is heated by gas & the a/c part is electric. It is also forced air... but it blows warm air. I've been extremely happy with it... except for the price of natural gas these days.

Good luck with twhatever you end up with.

 

[Geezer]

I don't have one, but I have spoken with engineers about installing them in my area. The bottom line is that it takes a long time to save enough energy to pay back your investment. In some cases, the payback is longer than the useful life of the system. If you plan on using it for cooling in the summer then your payback is better. The current technology calls for a single very deep well to be drilled rather than a series of shallow wells they used to use.

Do you have a natural source of heat to draw on?

 

[raclow]

I wouldn't use a heat pump in your area. I would use a traditional system, gas heat and compressor air/electric.

I would get a high efficient unit for the air...16 seer or better. For the heat, go with a two-stage system with ICM motor/s.

Example for heat...first turn it on to heat house it will burn at 100,000 BTU's until temp is reached. Then will run at 50,000 BTU's to maintain the heat unless it runs for 11 minutes without reaching the demand then the unit kicks up the fan speed and BTU's to 100,000.

Have your Heat and Air guy research this for you.

My two cents worth, hope it helps.

 

[ionbeam]

When my brother-in-law moved from the UK to the Boston, MA area he put a heat pump in his new house. Said B-I-L is a mechanical engineer specializing in thermodynamics so he viewed his heat pump as part environment controller and part hobby. The whole time he lived in that house he made improvements to the system. He tried using the heat pump in two ways, one was as a heat exchanger in a forced hot air system and later tried to use it as radiant heat source by circulating the water through tubing imbedded in an insulated slab under his add-on family room. Brrrrr!!!! In the end, it made a fair AC unit and a poor heat source. He used unreasonable amount of make-up electricity and burned a small forest through his wood stove. His wife was blue times two -- blue from the expense and blue from cold. I suspect that Nova Scotia would be even more challenging.

A heating equipment supplier should be able to hook you up with some heat pump users in your area as references.

 

[RonBB]

I've had a heat pump for the last 20 years. I live out of town in the country(near Kansas City) & natural gas was not available. It basically came down to either a heat pump, electric heat, or a forced air furnance with propane. The heat pump is a high efficiency unit and air to air, as opposed to a ground source unit. At the time I built the house I could not economically justify the ground source units. I would suggest that that calculation might yield different results today. The unit generally provides about three watts of heat for every one watt used to move the heat indoors from outdoors. Having said that I would also point out that the air to air units are not very efficient when the outside temperatures get below around 20 degrees. At about the 20 degree point many if not most units also turn on electric resistive heating to supplement the heat from the heat pump itself. I would install it again if I were to do it over in my situation. If I had natural gas available I would probably opt for a pulse type high efficiency type natural gas forced air system. I'm not sure about your location but I'd certainly give it considerable thought if it is around or below 20 degrees very often & I would certainly look at a ground source unit as well. Hope this helps best of luck with whatever you do.

 

[mdisher]

I actually don't have a clue as to what your climate is like... If it gets cold there (and I think it might), heat pumps are very good.

I'm not an HVAC engineer, but have owned a couple.

Basically, it's like this...

A heat pump essentially uses the AC Unit, and sort of puts it in reverse. The best you get out of it is 'luke-warm' air though. If that can't handle the heat needed (and they aren't all that effecient electrically mind you), then the supplimental or Aux heat comes on. That's typically plain old radiant coils inside the furnace, and you still don't get very 'hot' air. (think toaster oven for your house).

But if heating months are shorter, or rather you have more cooling months than heating, they might be worth looking at.

I've yet to ever find a truely 'efficient' A/C unit, and that's all you're using. They claim they don't burn fuel, because they aren't gas or oil driven. But your electricity comes from somewhere and for the most part that aint cheap.

I current heat with oil, because that's what in my house... When we replaced the oil furnace 5 years ago we looked at both again, and you can't beat the heat that oil produces. Back then it was cheap though, we paid $.68 to per gallon at the time, it's currently $2.25/gal which sucks.

If your climate has huge temp swings, from cold to warm, or gets very cold, I'd say stay away. Heat pumps are best for mild climates.

-MD

 

[keithaba]

1 word.... NO

I would not use a heat pump. I just built a house and they talked it up about how efficient it was, and how great they are. Mine blows. During winter, it never could get the house up to more than 65 degrees, unless I left it running 24/7. It also takes approximately one hour to raise the temp 1 degree. During the colder months, the average temp was about 37, my electric bill was like $320!

I don't remember which one I have, but they are rated by the SEER. Maybe mine is just too low, but I'm not pleased with it and I wish I had Gas. (Natural Gas that is) (I mean, for my heating)... sheesh you people and your sick minds........

clicky

 

[timk]

For a new house, I'd go with a Geothermal(sp).

 

[FJRay]

If you can use the ground for the heat source it will work well but once it gets cold out they are just a forced air electric furnace. Mine turns on the heating coils at 35 degrees and I have had 300.00 electric bills this winter keeping the house at 69.

 

[gypsy]

Unfortunately I am building outside the city so natural gas is not available. That would have been my first choice. The other choice really is forced air or hot water with an oil fired furnace. The house does have 2 propane fireplaces which can assist on the coldest days. Despite being in Canada we don't usually get long spells of cold weather. Nova Scotia is on the ocean so that moderates things. Although we get the humidity that comes with it.

I suppose I should find some people locally who have heat pumps to see how they have found it in the winter. As for the cooling in the summer we don't really need it. Weather just isn't that hot for that long. I would never go to the expense of installing a/c but if I have a heat pump already I would use it to cool when needed.

I guess I better keep researching.

Thanks for your input.

gypsy

 

[RonBB]

Heat pumps raise the recirculated air in the home only a few degrees but generally move much more air. The air coming out of the registers will not feel as warm as that coming out of a gas furnace. This means they generally run longer and setback thermostats are not recommended with them for this reason. Keithaba, I am wondering if your unit was undersized which would leave it running on the resistive heat more often thus raising your electrical costs. Just a thought. Best of luck.

 

[juniorfjr]

In our region, all new homes are heated with electric air to ari heat pumps. Very fortunate to have the lowest cost electricity in the u.s.a. Less than 4 cents kw hour. It is backed up with a forced air electric heater. Mine has run continously for 9 years with no problems. The air out of the register is not as hot as a gas or oil furnace. But we got as low as single digits this year without any problems. If you must do electric, it is the best option. jr.

 

[daytripper]

I have been in my new house for about a year. I choose a heat pump based on the rising cost of gas. I had gas heat in my last house. If I lived further north I would choose another energy alternative. Heat pumps work well until the outside temp drops into the mid twentys. For this reason I installed gas logs in my house and buried a 300 gallon lp tank in my back yard. When I get cold I run my gas logs to add a comfy warm temp to the house. This year I plan to add a whole house lp generator to the house and in the event of a power loss I can still have some heat, hot water, a few lights, and the microwave.

 

[DonRed7]

Negative on the heat pump..... I have a tech/friend that does some work for me at our processing plant that installed such during his build a few years ago. It was the "very large in ground grid recirc type" The electrical costs and controll troubles are not worth it. Put that extra initial input cost into wind generation and storage and you'll be better long term. If you wan't to chat with him pm me.

-Don

 

[gypsy]

Negative on the heat pump..... I have a tech/friend that does some work for me at our processing plant that installed such during his build a few years ago. It was the "very large in ground grid recirc type" The electrical costs and controll troubles are not worth it. Put that extra initial input cost into wind generation and storage and you'll be better long term. If you wan't to chat with him pm me.
-Don

Given everyone's advice I am now going to track down some folks in this area who have heat pumps and see what they have to say before making a final decision. Obviously the climate has a lot to do with it. The more info the better I figure.

Thanks again,

gypsy

 

[radman]

I have a heat pump, have had it for about 17 years. It runs through a power co controlled circuit-in exchange for them being able to shut it down for 8-10 min per hour during high-use temp extremes, I get a rate that is roughly 40% of the going rate. It runs year around, automatically switching to gas furnace back-up, either running separately or in tandem, depending on demand. It is an air-air exchanger. It can maintain home temp at 70 degrees on it's own down to about 30 degrees. Below that the furnace kicks in occasionally to assist, running more and more often until 5-10 degrees, when the pump shuts down, and the furnace takes over. In summer the pump has no problem maintaining the house at 70 degrees again, although in very hot weather, when they start cycling (this only happens in summer by the way) it can begin to rise so that on a one hundred degree day, it can get as high as 78 by sunset (and our house faces south-southwest). It has run flawlessly for the entire time we've had it, requiring only the usual filter changes and fin cleaning-straightening that any HVAC needs. It saves us 2-400 dollars a year on average, part of which of course is the lower electric rate we get. The sizing of the unit is critical-as it is, it runs just about perfect cycling wise, too large and it will not run enough, too small and it never shuts off. I would do it again in a heartbeat, given the same deal we have now. When I got it, the utility offered 3% money, payments included with the electric bill. A no brainer. It is a Janitrol by the way, with a scroll compressor. Oh, and temp range here is aprox 120 degrees.

 

[05fjrBluedevil]

I bought my house last december/ 05, it had a heat pump. I am total electric, with a fireplace that has a wood burning insert.

The heat pump works great in the summer for a/c, except because it is bigger than needed. the air flow is somewhat loud.

In the winter I noticed if the temp dropped below 45, it just never seemed to heat the place up... Now we did leave the therm set at around 65-67 all day then raise while home then lower prior to going to bed...

We found many times this last winter that it was colder here than the first winter, so the first winter season it was not bad at all, however this past winter, I found it blowing cold air, with the therm flashing aux heat, like the unit was looking for a heat assist, they say you should have an aux heat source if it gets to cold outside, like gas furnace etc.

Many times I would burn firewood all day and all night and that would surfice, to help the heat pump work better.

I did have a few 200 dollar lge bills, but in the summer right at 100. that is in a 2550 sq ft 40 year old house, but the heat pump/ac is only central on first floor..

many times the in wall electric heaters upstairs in the two room there were much nicer in the winter...

in the summer there are window units installed in the two rooms for a/c...

so if you could use the heat pump, and some type of aux heat source, lp, oil etc it may be more cost savings as gas just continues to go up in price.

 

[Wingman]

If your temps stay below freezing for more than 48 hrs on a regular basis, I would recommend a heat pump with backup gas/propane heat along with the usual heat strips. Normal operation would be heat pump, but would revert to propane when the outside temps drop. The emergency heat (electric heat strips) would be used only if you ran out of propane or experienced a failure of some kind with the propane furnace.

Heat pumps are very efficient if you are willing to set the thermostat and forget it. As mentioned, they take time to raise the temp, so setting the thermostat to change the temp while you are away is not usually cheaper (assuming you will be insulating the house well). You can set it lower if you will be gone for the weekend or longer, but I don't recommend setting more than 10 deg F lower than usual.

Your thermostat will need an outside air temp probe for most cost efficient operation with a 3 stage heat. This allows the unit to switch from heat pump to gas when the temp reaches a certain point. This temp is usually near the freezing point, but is actually set based on cost of gas/propane vs. electricity. With costs of propane and electricity in hand, any good HVAC installer should be able to use the formulas to determine this temp for your installation. Without an outside air probe, the unit will be capable of switching to backup heat, but usually only when the heat pump unit cannot maintain the set inside temp. This thermostat setup costs a bit more initially, but should pay for itself in reduced operating costs.

As others have mentioned, get a system with a high SEER rating. The higher, the better. The highest you can afford is my personal recommendation.

The most important thing to remember when dealing with any kind of HVAC or refrigeration is that the equipment is only as good as the installation. Find the BEST installer in your area, instead of shopping for the cheapest price. A good installer will take the time to calculate all the variables when load sizing a system for your installation, and take the time to explain everything to you.

David