Heat pumps in the state of Washington - good, bad, indifferent?

[Bill Dewey]

Having just been thoroughly chastised at alt.hvac, sometimes I just love the Net Police, it was suggested that I post my question here. To add a bit more context, I have been searching Google for a few days now and have not really found much that is definitive. I am trying to understand the technology from the point of view of a consumer, not a system designer, and to become educated enough to determine if the contractor/consultants we deal with are worth a hill of beans :-). My field is Software Development, and I can assure you that every good consultant/company there are 100 hacks that will take your money and give little value. My experience is that this is common across all fields and that quite often system failures are a result of not knowing enough to ensure that you get one of the "good ones".

We are awaiting completion of a new home in the Marysville area of Washington, about 30 miles North of Seattle. I am considering speaking with the builder about putting in a heat pump rather than a conventional gas furnace. We don't often get temperature extremes in this area, a few weeks of sub-30 degrees in the winter is a cold one and a few weeks of +80 is the summer is a warm on, although you would be hard pressed to believe the latter had you been here the past of couple of weeks :-).

I don't know much about heat pumps, other than the "big bits" sit outside. What is the feeling about this being cost effective in this climate and what should I look/ask for? If we do go with a heat pump, should we be asking for any changes in the standard duct work regarding placement? Our alternative is to add a couple of ceiling fans for cooling and circulation along with a conventional gas furnace.

Please make the assumption that I don't even know the right questions to ask of the group and help educate me. This statement got me reamed on alt.hvac for "being lazy". What this is is an acknowledgement that the professionals in this area know a lot more than I do, and any tips that I can get to vet a good installer/contractor will certainly help. Ideally would be to find someone in the area via this NG that I could do business with. Not that I don't trust the builder, but I don't even trust myself :-).

Thanks in advance, much appreciated.

[~KJPRO~]

professionals

Nice to see you made it here!! :-)

To start with answering your questions....

Anybody that wants to install a system in your home needs to start with a Manual J & D. This will insure they size the units properly for your particular home. Manual D, will insure that the duct system is adequate for the size of equipment.

After that, they need to qualify your particular needs.....

Air filtrations needs....do you need better filtration due to allergies? Humidification....due to cold dry weather conditions. System noise, are you concerned with system noise? Temperature swings.....etc, etc....

Then after they know your needs, they can set up a system that will perform well to your particular requirements

Heat Pumps really don't work well in area's where the ambient temps drop below 32 degrees. Also, HP will require larger ductwork for them to operate efficiently.

I would look into getting the highest efficiency gas fired furnace you can afford. Find the best installer you can find. The installer is more important then the name on the equipment.

Your buying quality that the contractor is providing for you. This is something you will use for years to come, so don't skimp on the initial install. Doing it right the first time is a must, as it will cost BIG dollars to fix any mistakes later down the road.

Also remember your comfort relies on the contractor you choose, so make a sound decision on quality and not a 'low bidder' syndrome.

Good Luck, ~kjpro~

[Bill Dewey]

(my old drivel snipped, you can read it in the thread if you care...)>

Thanks for the civility and for following me here to help.

OK, most of that I have seen elsewhere on the Web, at least the references, execpt for the tips on "particular needs", that is good info to keep in mind, thanks.

I have seen reference to this several times, and it is one of the reasons that I wonder if this is the right climate. Given that we don't get many days/weeks of sub-32, would the heat-pump still be a good idea? Is this why you suggest still having a high-efficiency gas fired furnace as well, for those days that are below 32? From what I have been reading, mostly manufacturers sites which is always hazardous :-), I thought that the heat pump replaced the furnace and added AC for "free" (yeah, right).

I suspected as much, which is why I want to understand some of this before they get too far in the build process.

Now THIS is the real crux of the issue, isn't it? How does one ensure that the contractor really has a clue? Always tough, even when you get good references.

From what you have said here, and a few other bits I have found, I am wondering if a Heat Pump is really the best solution, of if I should just stick with a gas furnace and supplement with ceiling fans, which was my first thought. Is there a "generally accepted" temperature range/climate where heat pump technology by itself is best suited? It sounds as if the floor is at 32-35 F for air-to-air (right terminology?) and a bit lower for ground-source(again, correct terminology)?

By the way, one thing you said above that really hits is the "high efficiency" furnace. That is one thing we should look into regardless of what we do, as I am pretty darned sure the "builder standard" is somewhat on the mediocre side :-).

Well, my next endeavor will be to ask about tankless "instant-on" water heaters, who knows where that will go :-).

Thanks a bunch, kjpro, much appreciated.

[~KJPRO~]

Nothing is free.....it's the quality of the purchase that matters. (you can pay now for a quality install, or pay more in the long run!!)

In an area, where the temps drop to a low and the HP can not produce the require btu to heat your home it has electric back up strips to supplement the HP. This is where you could end up paying high energy cost compared to running a high efficient furnace.

The builders in our area normally install 80% furnaces, which is completely insane. I haven't install an 80% for quite some time now. If you install a high efficiency furnace like 92%, you save 12 percent of the energy you input into the furnace. So take easy figures $1000 in fuel cost per year with a 80% furnace....$800 stays in you home as the other $200 goes right the chimney.

Now on the other hand the 92% is only going to input $870 to get the same $800 worth of heat, saving you $130 per year. At 1300 per 10 years. Now you have to figure out how long you are going to be in the home. (10-20 years? = $1300-2600)

While the cost difference in the initial install could be as low as $500, saving you some MAJOR cash.

Also, you may want to invest in a two-stage gas fired furnace to save even more money. As it will fire on a low setting in low load conditions and fire on high when it's -30 outside.

Remember the longer the furnace runs, the better efficiency and filtration you are getting. (compare it to your car, 'longer trips' better fuel mileage)

~kjpro~

[PrecisionMachinisT]

Heat pumps with gas backup are likely the best choice around these parts.

Rarely does it drop below freezing here for extended time periods.

[~KJPRO~]

I was concerned when he mentioned the -30 temps, but I won't argue with your view as you are in his state and know the weather conditions.

~kjpro~

BTW, to the OP this is another professional!

[Bill Dewey]

(snipping to make this shorter)

This all makes sense, thanks very much for the tips on the High Efficiency furnace.

SVL, if I am going to have a gas furnace as backup, and since the "high" heat only occurs a few weeks a year, what is the advantage then of putting in a heat pump at all? Is there enough energy savings realized to make the ROI worthwhile? For me "worthwhile" would be considered 10-15 years, as I imagine that at about that time I would be looking at potential repair/replacement of the HP. Given that my "guess", which is very uneducated at this point in time, of $4000-$5000 for the HP and install this would mean that I would need to realize a savings of $400-$500 for a reasonable ROI, ignoring the added cost of yearly servicing.

I am beginning to think that while this technology is interesting, the cost/benefit to cool the house for a few weeks may not be worth it. Am I looking at the correct factors here?

Also, if I am looking at a high efficiency gas furnace, specifically a two-stage, would it be more cost effective to add an AC unit if I decide the cooling is something that I really "need"?

Thanks, folks, this is really helpful and has yielded, in a short time, a whole lot more than about 6 hours of Googling....

[~KJPRO~]

Yes, this is the proper thinking.

Also a standard air conditioner has fewer parts to cause problems then the HP does. Make sure of one thing that can save you money for installing the air conditioner later, have them install a coil box on the furnace. This way the coil can be added easily in the future.

~kjpro~

[PrecisionMachinisT]

Hi, kj.......

No no nooo......Im flattered, but Im a just a homeowner and semi retired aerospace machinist turned machine shop owner who happens to have been cursed from birth with an intense curiosity about how mechanical things work.

I only know enough about hvac to get by mostly for myself, and I never done it as a professional in my life.......

Much of what I have learned most recently about hvac is through mainly lurking and listening to the real pros such as yourself and several others over in alt.havoc, where over time most of the regulars have gotten to where they at least tolerate my occasional....errrr...."contribution".......

Cheers,

[~KJPRO~]

Well, shit man....you have more intelligence then the 'Davey/Stormin' type of so called pro's! LOL

This clears up some of the things I see you post, I just say to myself "wtf is he saying"! :-)

~kjpro~

[PrecisionMachinisT]

I run heat pumps in the shop and the house, I have 12 tons capacity total.......the house is 7500sf and the shop is ~ 1600sf

So heres the main thing I know :

When the weather does occasionally dip down to around ~37 degrees here, my power bills close to abruptly triple because of the electric backup heat kicking in.......this happens unless I build a nice fire in the woodstove and / or hack in a water source unit and reject heat from the ground or out of the swimming pool for a spell..........

========

Thing about heat pumps for me is that since I basically melt and my body shifts into low gear when it gets hot, having the ability to also cool is definately something I need--especially in the shop, as I have machinery in there that places a large additional cooling load on that system during warm weather, and most of the year they are relatively inexpensive to operate in the heating mode in this area.......

So now back to what kj said--if your undecided and under the gun to make a decision soon, I would agree the best option would be to at least make sure the ducts are sized sufficiently large and a coil box put in so that ac or heat pump can be installed at a later date--basically the equipment that goes inside the house is the same regardless of whether it is a straight A/C condensor or a heat pump sitting outside on the pad........

Now, I could point you to numerous technical charts and graphs showing performance curves and that kinda thing about heat pumps, but what you might find best for finding the least costly system to operate would be to go ahead and contact your gas company and also the electric company up there and ask them--usually they have pretty straight forward answers as to the cost of operation in their area--and they might even have some programs available where you could get a rebate for installing certain types of equipment because of energy conservation programs in effect.......

[PrecisionMachinisT]

.....LOL.......

So, I guess I moved up a notch ???

Cheers,

[Chris Lewis]

According to Bill Dewey :

Did you say that your temperatures occasionally get to -30F, or 30F? "sub-30" is ambiguous.

While I don't get into the numbers much, a heat pump with electric backup would likely work quite well if you rarely go below 30F. The break-even point of the pure HP mode[1] can vary quite a bit depending on the unit itself and specific electrical costs. Installation break-even points can be as low as the 25F area, and some are in the 35-40F area.

We had a HP/gas combo whose HP unit was quite good to about 25F or so.

That said, even though you may dive below the cutover point, even expensive heat (electric) _may_ still be optimal if the sub-cutover point temps are rare enough.

If you say that you almost never get under 30F, then a HP with electric backup will probably do better than gas, certainly better than pure electric.

Another way of looking at this - a properly adjusted HP unit can _never_ be worse than running on backup heat all the time. So if your backup heat is electric, a HP/electric combination _cannot_ be worse than pure electric.

Similarly, if your winter temperature are lower, a HP/gas combination will be significantly better than pure gas, let alone HP/electric (assuming reasonably standard electric/gas pricing differentials)..

Consider how long your house is above the HP cutover point, but still needs heat. In your area, as it is in mine, that's a big part of the year. I suggest consulting a professional HVAC contractor (who doesn't have a particular axe to grind, or get multiple opinions) and get them to run the numbers _specific_ for your situation.

In other words, I'm not going to make a specific suggestion other than asking someone who can run the numbers for you with a knowledge of your precise circumstances.

[1] Where the temperature is low enough for the backup to be more cost-effective than HP mode. This doesn't factor in backup/long term at all. In other words, this is approximately the place where the HP _should_ switch over to backup.

[Joseph Meehan]

I believe it would be a very good area for a heat pump, unless you are north east (in the mountains). However I would pay attention to what the local HVAC professionals say. Be sure to have all the correct calculations done before you decide.

In the past you have been blessed with very low electric rates, but that is coming to an end. That would tend to push the choice to heat pumps.

[SQLit]

professionals

Heat pumps start loosing effectiveness at about 40 F. Stick with gas heat and a straight cool unit. Ceiling fans cool people not spaces. When your in the room they work when you leave turn them off.

play what if on this page http://198.147.238.24/ac_calc/default.asp

[DoctorElefant]

Just curious, as I've never had the pleasure of visiting WA... are there many electric furnaces in that area?

DocE

-------- "The future ain't what it used to be." -Yogi Berra

[PrecisionMachinisT]

Not really that many anymore, I would have to say........when electric power was real cheap a few decades ago many people used electric baseboard, floor or ceiling resistance heating........

But if by "furnace" you mean air handlers having electric heat strips installed, yes these are now quite common in this area, chiefly being used for backup heating in heat pump installations--likely more common than gas......this probly due to the fact that gas may not always be readily available at every given location.

[DoctorElefant]

Yes, that's the kind of furnace I meant. Thanks.

DocE

-------- "The future ain't what it used to be." -Yogi Berra

[Tony Hwang]

I have Carrier heat pump in my sn room. It works quite well for colling/heating. Even in dead winter with outside temp. ~-30F, it does the job. Matter is having suffcient capacity to begin with. Under sized one will never work right. Lucky I have a bro-in-law who is commercial HVAC engineer. Tony

[~KJPRO~]

And if it's like most commercial applications.....

It's way oversized! :-)

~kjpro~