Well, a heat pump is a heat pump. 'Air source' means that it extracts the heat from the air, as opposed to water (swimming pool) or ground (geothermal). My air source heat pump which heats my house works just fine down to 32F, so unless you keep your basement that cold, it should work just fine at 60F.

Will it make the basement cooler? Probably. It may also dehumidify it a bit, too.

Twice as efficient? That I wouldn't know. Nor could I speak to the maintenance or longevity of something this complicated (though people keep HPs for 10's of years).

yes I have a heat pump as well....I guess the considerations are: 1) what doe sit cost, 2)what does it save me, 3) how much colder does it make the basement.

Anyone have one of these type water heaters?

The unit should have one of those little yellow tags that gives energy usage. You can use that along with the cost of purchase and installation to compute a total cost of ownership. Then compare that to a traditional water heater and see what the payback period is. There may government and local utility credits available as well, so throw those into your calcs.

According to Rheem's site, it's efficient changes based on geographic location so make sure you consider that. I'd also bet that their claim of energy savings is based on an ideal location. There are also some physical space requirements that you want to be sure to note.

The unknown, of course, is longevity and maintenance. A traditional water heater is a pretty simple device and repairs generally aren't that expensive. Start adding compressors, fan, control circuits and the like and repairs could be expensive and would likely require a trained technician.

This is certainly interesting!

Okay, here's the rub: The unit is taking heat from the surrounding area and using it to heat water. If you are paying to heat that surrounding air, this is a bad deal.

On the other hand, if you aren't paying to heat the air around the heater - or you are paying to cool the air around the heater - it's a good deal.

The complexity factor is an issue that will need to be a "wait and see" issue. Since this a factory sealed unit, unlike the heat pump in your house, it doesn't require someone who knows refrigeration to install it. That's a big plus because a lot of problems with A/C and Heat Pumps are actually a problem with bad installation. This is more closely compared to a refrigerator - it's all self contained.

I could see this being a big plus in warm weather climates where it was installed in a garage or attic.

Yea...Well I just had a few heat vents dropped in when my new Trane system was installed so unless it pipes that cold air outside I think I have my answer. Also, I wonder how much noise it makes...

I have had the Rheem HP 50 water heater since March but have seen only about $3 a month savings which isn't enough to make the extra cost of the unit worth while. My electric company put a meter on it as they wanted to know how efficient it would be and we are dissappointed so far.
Right now July 26, 2010 we waiting on repairs as the unit quit working on the two higer settings. Rheem doesn't want to send a service manual to my Rheem Certified repair man so he has to work with them over the phone and it is taking a long time to get it fixed.
I would not buy another Rheem Heat Pump unit as it just doesn't have the savings they claim. It does make noise like a noisey refrigerator. It does cool the basement some but that isn't a problem for me as I have a wood furnace in the basement, which should make the heat pump run more efficiently yet.
I have a problem with black rust which gives the water a rotten egg smell and they say I need to have an aluminum anode rod in my water heater but you can't replace the annode rod in this water heater.
I never had this problem with my old coventonal electric water heater