Heat your water with a heat pump - 50% electric savings!

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.
Mike from Athens said:
Airgenerate emailed their label to me. It does mention UL standard. Unfortunately, I don't know what it all means.

What the testing stuff means is that the unit was NOT tested by "UL" itself, but by a 3rd party testing lab, which is fairly common practice, as UL does very little testing itself. The test lab is "ETL" - couldn't read the label enough to see what that stands for, and they tested it to a set of listed UL (United States) and CSA (Canadian) standards - The numbers are the ones that the respective agencies think are needed for the particular type of device. For all intents and purposes, this is the equivalent of "UL Listing" - it should keep insurance companies, code inspectors and so forth all happy as long as the product is installed and used in accordance with the mfgr directions...

Also keep in mind with ALL products - UL, CSA, or other safety agency listings do NOT make any promises about a product working, doing what it says it will, efficiency, or other such things... The ONLY thing they promise is that the product (probably) won't do anything in normal operation, or break down, in a way that will cause your insurance company (i.e. the "Underwriter" in "Underwriter's Lab") to have to pay out any cash - i.e. it won't fry you, burn your house down, and so forth... IOW, it doesn't have to work, it just has to not hurt you...

Gooserider
 
I ended up going with the Airtap.

The Airtap is working well in our installation; with summer basement temperature ~70F, I measured an Energy Factor of ~4.1 for the initial tank heat-up; this will decrease to ~2.5 with winter basement temps in the 50's. Installation was complicated by that fact that the hot water stub wouldn’t come out- my plumber thought it was welded in, as he's seen in other cheap retail-store tanks; so we needed a new tank. Advice for other installations- soak the hot water stub threads with PB Blaster for a few days in case they’re seized. I had the connections all ready to go for the installation- installing the new tank and Airtap took the two of us only ~30 min. The units now shipping have an anti-icing switch, a longer thermostat run, and a 10F delta thermostat; together these updates seem to get around the problems with earlier units.

Payback time is a bit longer than the 2-3 years that I was hoping for- probably ~5-6 years, due to added cost of new tank, and the fact that we're only using ~half the hot water/day that I had expected. We need to take more/longer/hotter showers! But it's no noisier than our dehumidifier, which we no longer run, and we have a drier basement to boot.
 
The Geyser, yep, that's what I'm looking at. The airtap won't fit to my Amtrol tank. The Geyser will however. Just wondering if DIY will qualify for the tax credit, but thats another post.
 
It worries me that the AirGenerate website does not mention the new non-icing product. Equally, they have removed their forums which had a lot of complaints about icing. Finally, and this I think is just poor marketing - their "calculate their savings" does not include an 'oil tankless' and 'oil suprastore' option, plus their electric cost is way higher for me than it should be (0.17 compared to mine of 0.125/kWh all in).

I really like the idea of their product, but frankly their marketing just sucks - as this is my only real way to judge them, it makes me think twice...
 
We have installed an Airgenerate unit and recently a Geyser.
The AirTap has icing problems in cooler basements.

The Geyser is quite quiet and I think you get what you pay for.

We are thinking seriously about offering them (The Geyser, that is) as an option with our tanks as a backup for wood and solar.

I believe they are eligible for the rebate as a DIY project.
 
Any idea what the MSRP is on one of those Geysers? Their website is kinda light on details and some of their numbers look a little puffy to me. Thanks.

Chris
 
Yes that is quite a jump. The older units were retailing for $1,000. The $600 units were refurbs that they blew out. That was a great deal.

I can tell you that the new ones are quieter and smaller. I believe they perform the same, but are plug in 110v instead of the more complex 220v system that was not simple to make work with anything other than an electric hot water tank.

Compared to the Airtap, there is a lot more under the hood.

I guess you get what you pay for.
Tom
 
I've been lurking and think the details the rest of you have given this topic is great.

I just saw a pre-mo for a GE unit. I guess they are finally taking this market as a good energy saver. See:

http://www.geappliances.com/products/water/heat-pump-water-heater/?cid=14249&omni;_key=(b)Non-Brand_|_Water_Heater-heat_pump_-Heat_pump_water_heater

I'm also concerned about using the Airtap with teh tank coils active, since the copper heat exchanger could be in contact with them. THis might be a reason that they are having trouble getting UL approval.

BobZ
-----------------------------------------------------
No solar or geothermal, but just starting
 
It is my understanding that the hx on the Airtap is single wall and it will not pass UL nor some code jurisdictions since a breach of the hx will put refrigerant oil into the potable water.
That would be less of an issue with our tank since we would have an effective double wall to potable, but I don't want oil on our liner.
 
We've had the Airtap now since late-June. In response to numerous pre-purchase queries, I got the following from AirGenerate:

"The AirTap has actually always been double walled and continues to be so.

The AirTap meets UL certifications, but is not yet certified. The AirTap
has multiple industry certifications: NTS (National Technical
Systems), GAMA (Gas Appliance Manufacturers Association, which recently
merged with AHRI, the Air-Conditioning, Heating and Refrigeration
Institute), and CSA.

NTS TR-301499-06C applies, the unit is certified to CSA standard C22.2 No.
236, and the AirTap is safety certified by ETL/Intertek with UL-1995
standards."

As I mentioned earlier, I'm not expert in evaluating these statement.

The Airtap manual states that the power to the elements in the main tank should be permanently disconnected; I suspect, as mentioned above, they don't want close contact between the hot elements & their freon line.

Also, in response to previous posts, the currently shipping units (mine included) have an anti-icing switch. It's no noisier than our (now unused) dehumidifer.

We've only used it in summer, but to date, we'm very pleased with the results, & we're on track for a ~4 year payback time.
 
I'm looking to get an airtap unit soon. I will replace my 40 gallon electic HW heater with an 80 gallon (we have a large 60 gallon whirlpool tub so this needed to be done anyways). I will also probably do the same modification to use the tank thermostat to make sure the unit keeps up with heating water regularly. I imagine it would take quite some time for the airtap to heat 80 gallons back up to temp, so it seems like although this will affect efficiency, the thermostat is a must for people who require hot water at most times during the day. Has anyone figured out how much more electricity they are using by doing this modification versus using the airtap Tstat?

I have a pellet stove in the down stairs, where the furnace and water heater are located, so ambient should be pretty toasty down there. I also have an unused refrigerator in my furnace room, so i'm thinking of feeding the cool exhausted air into the refrigerator in the winter months, and then i'll undo this in the warm months. Maybe it will even get cold enough to keep some beverages cool.
My ultimate goal is to put in a good size sollar collector array for DHW. However i probably won't get around to this for a couple years. I can then rely on the airtap unit as my solar backup. So in the interim i feel this airtap unit is a good investment, with realtively quick paypack. I can get the airtap for 599, and then the new 80 gallon HW heater for 150. Plus the 30% tax credit, it almost seems like a no brainer.

Does anyone see holes in my plan or want to provide some further insight on real world gained efficiencies they are seeing with their airtap or geyser?
 
Currently shipping Airtap units, mine included, contain a longer thermostatic probe than earlier ones- so use of the tank thermostat may not be necessary. Check with them.

7K BTU translates into something like 12 gal/hour water heated to 120F. If your needs are occasionally higher than 92 gal/hour, perhaps keep your current tank, putting the Airtap equipped tank first as a preheat, with the older tank in series set at lower setpoint to provide extra capacity. A neighbor has done this & it works well.
 
JayH said:
We've had the Airtap now since late-June. In response to numerous pre-purchase queries, I got the following from AirGenerate:

"The AirTap has actually always been double walled and continues to be so.

The AirTap meets UL certifications, but is not yet certified. The AirTap
has multiple industry certifications: NTS (National Technical
Systems), GAMA (Gas Appliance Manufacturers Association, which recently
merged with AHRI, the Air-Conditioning, Heating and Refrigeration
Institute), and CSA.

NTS TR-301499-06C applies, the unit is certified to CSA standard C22.2 No.
236, and the AirTap is safety certified by ETL/Intertek with UL-1995
standards."

As I mentioned earlier, I'm not expert in evaluating these statement.

The Airtap manual states that the power to the elements in the main tank should be permanently disconnected; I suspect, as mentioned above, they don't want close contact between the hot elements & their freon line.

Also, in response to previous posts, the currently shipping units (mine included) have an anti-icing switch. It's no noisier than our (now unused) dehumidifer.

We've only used it in summer, but to date, we'm very pleased with the results, & we're on track for a ~4 year payback time.

Can I ask why you are only running it in the summer? If it's saving you money in the summer by not using oil, the same is true in the winter. Just because your furnace is running, doesn't mean that the HW is now free. I'm sure there are some slight efficiencies as the furnace will run for longer typically, and your airtap will be less efficient as basement temps will be lower, but would be interested in your take on this.
 
Can I ask why you are only running it in the summer? If it's saving you money in the summer by not using oil, the same is true in the winter. Just because your furnace is running, doesn't mean that the HW is now free. I'm sure there are some slight efficiencies as the furnace will run for longer typically, and your airtap will be less efficient as basement temps will be lower, but would be interested in your take on this.

Sorry- we only had it installed this summer. I'm expecting that with winter basement temps in the low 50's that efficiency will drop to ~2.5, which is still quite good.
 
JayH said:
Can I ask why you are only running it in the summer? If it's saving you money in the summer by not using oil, the same is true in the winter. Just because your furnace is running, doesn't mean that the HW is now free. I'm sure there are some slight efficiencies as the furnace will run for longer typically, and your airtap will be less efficient as basement temps will be lower, but would be interested in your take on this.

Sorry- we only had it installed this summer. I'm expecting that with winter basement temps in the low 50's that efficiency will drop to ~2.5, which is still quite good.

Got you.

I've seen enough posts here from people thinking that DHW is free if their furnace is running anyway.
 
CarbonNeutral said:
JayH said:
Can I ask why you are only running it in the summer? If it's saving you money in the summer by not using oil, the same is true in the winter. Just because your furnace is running, doesn't mean that the HW is now free. I'm sure there are some slight efficiencies as the furnace will run for longer typically, and your airtap will be less efficient as basement temps will be lower, but would be interested in your take on this.

Sorry- we only had it installed this summer. I'm expecting that with winter basement temps in the low 50's that efficiency will drop to ~2.5, which is still quite good.

Got you.

I've seen enough posts here from people thinking that DHW is free if their furnace is running anyway.

It seems possible to me depending on the setup and so forth that while the DHW wouldn't be "free" if the boiler were running anyway, it might be the case that it would be less than running an airtap or other form of water heating... I suspect that this would be something that each person would need to work out for themselves as it would depend on just how the furnace water heating was set up.

Gooserider
 
Gooserider said:
It seems possible to me depending on the setup and so forth that while the DHW wouldn't be "free" if the boiler were running anyway, it might be the case that it would be less than running an airtap or other form of water heating... I suspect that this would be something that each person would need to work out for themselves as it would depend on just how the furnace water heating was set up.

Gooserider

You could be right - perhaps the cold water in the DHW part of the boiler helps pull more heat out that doesn't go up the flue, but at the end of the day you have to use X BTUs to heat X gallons of water. Certainly in my system (tankless oil) I would still be far ahead with even a normal electric heater.
 
I think I mentioned that I have both the Nyletherm, an Airtap and now a Geyser.

The Airtap is installed at my daughter's house and we had the discussion about shutting it down soon, or expecting the unit to freeze up as it gets colder out.
This is what it does when it gets cold out and will not work consistently in the winter in her basement.
A basement with a wood stove or boiler would not be a problem.

The Airtap is not UL listed, and I suspect, it will not be. The heat exchanger is not double walled. It is about 1/4" in diameter, so how is this double walled?

Meeting UL certifications is not UL listed.

Of the three units, the Geyser is the most expensive and I think it offers the most advantages. It is double walled and UL listed. It also lists for $1400.
It is quieter than the other two and can be re-used from tank to tank.

I worry that the Airtap hx will fail with aggressive well water.

In full disclosure, you should know that we are offering the Geyser on our website. You can't beat the Airtap price, but for how long?
 
Yes, it is quite a spread. The Nyletherm actually retailed for $1000, but they regularly had discounted refurb units that went from $6-800.

If you were installing it with anything other than an electric water heater, you had to do some odd jerry rigging with a resistor.
I took my unit back to Nyle because I was sure that I blew out the controls.
Fortunately it is more robust than that and they got it set up for me. I was the first person to use it without a standard electric heater, I guess.
I have used it for three years and it works great.
The Nyletherm is no longer available as the Geyser replaced it.
 
Tom in Maine said:
Yes, it is quite a spread. The Nyletherm actually retailed for $1000, but they regularly had discounted refurb units that went from $6-800.

If you were installing it with anything other than an electric water heater, you had to do some odd jerry rigging with a resistor.
I took my unit back to Nyle because I was sure that I blew out the controls.
Fortunately it is more robust than that and they got it set up for me. I was the first person to use it without a standard electric heater, I guess.
I have used it for three years and it works great.
The Nyletherm is no longer available as the Geyser replaced it.

They gave me the wrong wiring diagram when I got mine. I had it wired the way they said and nothing. Called them up and finally got the right diagram from Don himself. I'm on my 3rd year also. Of course I heard about it on your radio show:)
 
Status
Not open for further replies.