heat pumps and hot water heat pump heaters (Phoenix: credit, house)

[KatrynS]

Would like to get off gas (access fees make being on one fuel source attractive), but house has a gas WH and gas furnace (WH in garage, furnace in attic).

Anyone have experience moving to a hybrid electric-heat pump water heater?

Have dual ACs -- could a heat pump replace the need for the furnace? Could augment with space heating if needed. Reduce load on ACs?

In Denver, heated house in winter to 62F and AC'd in summer to 78F. Got lots of sweaters and blankets for the kiddos.

I understand the "theory", just want to know how it really WORKS here in PHX.

Thanks!

[Ponderosa]

I don't have a figure but literally thousands upon thousands of homes here are heated and cooled by heat pumps - including mine. I have never owned Phoenix home that had gas.

Heat pump water heaters are a recent offering. I suppose they work OK, but they do cost a lot of money and certainly are more complex than an old fashioned electric or gas one is. If you want to spend money on a water heater, consider solar. I had one of those in a past home. Worked great with nearly unlimited hot water - cost pennies a year (for circulating water when the temps drop below freezing) to operate.

If you keep your winter temp at 62, you may not even need a heater here!

[Desertspiritsteve]

I think heat pumps are great. They have a much softer heat than the old gas blast furnaces blowing 140 degree air. The theory is that they move heat from one place to another. They don't burn up fossil fuels to create heat. Rheem makes some hybrid hot water heaters for about $1500. Figuring a one third tax credit, $1000.? They are supposed to be really efficient. You get some ac to boot wherever they sit. I see that Lennox is making some solar heat pumps. They probably cost a fortune to buy. You'd get a little kick on your air conditioning during daylight hours as far as I can tell. Another way to go is the ground source heat pump that transfers heat into and out of the earth. All you need to do these things is your life savings. This is a good time to take advantage of energy credits and rebates, utility company and government.

[Zippyman]

I'd have to agree with dumping the gas if your heating and cooling equipment is old anyway. The "minimum bill" approaches $50 if I remember correctly.

You can get plenty of heating power from a heat pump - most dealers suggest adding electric "heat strips" to your air handler to give you even more btu capacity, but my old heat pump didn't have them and even without extra insulation we were able to keep the house nice. I'd run the heat for an hour or so on cold mornings, but once the sun comes up you don't really need alot of heat unless you're really sensitive to it. Electricity is much cheaper in the winter, so even if your really use the heat pump alot, you won't get hurt.

As for heat pump water heaters, I have one - we've used it for almost a year now, and it is super cheap to run. I plugged it into my "kill-a-watt" meter for a couple of weeks last winter and entered the cost per KW as 22 cents (summer peak rates). The meter measures what the device actually consumes, and it came up with a figure of $10 a month - that was assuming that it always ran during "peak" power rates.

I bought the "Airtap" unit that sits on top of any standard gas or electric water heater - it has a long element that "fishes" down into the tank to heat the water. I bought a new 50 gallon electric AOSmith water heater from a guy who sells them on craigslist for $200, and the Airtap was $699. I ran the electric wiring so I can use the elements in the AOSmith unit if the Airtap ever breaks, but I leave the circuit breaker turned off.

The Rheem and GE "hybrid" units seem pretty cool, and the 10 year warranty is really nice, but it kinda reminds me of the whole "TV-VCR" combo things they used to sell - if the vcr breaks, you gotta toss a perfectly good TV in the trash...

[Desertspiritsteve]

I found some youtube videos for the Rheem. This thing looks great! would it air condition the area it was installed in?


YouTube - Rheem HP-50 Hybrid Heat Pump Electric Water Heater Preview

[Zippyman]

I wouldn't expect much cooling - our incoming water temps are around 72 degrees, so they don't need to run very often. Mine runs for maybe an hour or so a day. I mean, it's nice when it's running - but parking a hot car in the same garage releases all of the btu's from the engine into the same space, so it certainly won't turn a 95 degree garage into a "mancave"... too bad though!

I remember reading a post on another forum that mentioned some army base housing that had heat-pump water heaters back in the 1970's.

The homes weren't air conditioned, and the poster mentioned leaving a "hot" faucet cracked open at a dribble so the water heater would stay running all the time and cool the room.

[Desertspiritsteve]

It looks like a good idea though. I have read your posts carefully and enjoyed them. I guess that at some point I will have to put up some solar panels. I don't want them on my roof, so I have been dreaming up a pergola for my back yard.....dual use...shade and energy. The solar panels are supposed to trash your roof and they don't look good.

[KatrynS]

Originally Posted by Ponderosa

If you keep your winter temp at 62, you may not even need a heater here!

Yeah, but from what I hear we've got maybe 2 years before we fully "adapt" and start getting the chills at anything below 80F.

If I can get the WH off gas I won't even have to start gas service and that'll give us time to decide on whether a heat pump would be worth running instead of the furnaces. Probably only would need to heat the zone with the bedrooms. If I'm cold in the house, gives me an excuse to bake something.

[Ponderosa]

Originally Posted by KatrynS

Yeah, but from what I hear we've got maybe 2 years before we fully "adapt" and start getting the chills at anything below 80F.

If I can get the WH off gas I won't even have to start gas service and that'll give us time to decide on whether a heat pump would be worth running instead of the furnaces. Probably only would need to heat the zone with the bedrooms. If I'm cold in the house, gives me an excuse to bake something.

You could easily swap out the gas WH for standard electric, but you do need 220 amp wiring to the location. I don't know what heat pump WHs require.

I think you would have to swap out both units for HPs and that could get costly - way more than the gas base fee would ever add up to. But if your units are old and need replacing it could make good sense to go heat pump all the way. You do not need heat strips here, but if you want them, you're going to have to put in a pretty heavy 220 amp circuit in for them.

[Zippyman]

Originally Posted by Ponderosa

I don't know what heat pump WHs require.

110v outlet, 7 amp max draw..., nothing fancy.