Energy Efficient Heat Pump Water Heater

[gadgetgary]

Saw this in the Homo Depot flyer today.

Is is worth the initial outlay?

How does it compare to a traditional electric water heater, and the new 'tankless' water heater.

Thoughts?

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?jspStoreDir=hdus&catalogId=10053&productId=202065074&navFlow=3&keyword=542117&langId=-1&searchRedirect=542117&storeId=10051&endecaDataBean=com.homedepot.sa.el.wc.integration.endeca.EndecaDa

 

[favorit]

It's a more efficent unit, it draws less than half than a regular electric heater.
Basically is a A/C units : it cools the room air where it is installed and heats water. In case the room may be too cold there a backup 2000 W heating element that heats water.

The heat pump compressor is round 300-400 W so it draws far less than a regular element.

Heating water with a regular heating element is the least efficient way to do it, no matter one may have cheap power rates. To produce electric power in a regular power station you have to

- produce heat
- use this heat to produce steam
- use this steam to run turbines
- transform turbine mechanichal power into electric power

Each of these steps implies a loss of energy. So if you use regular elements to heat you have a further step to turn back electric power into heat, meaning 5 steps to have heat from heat. to have a certain X amount of heat in the last step you have to start with 1.4 X amount of heat in the power station

 

[brisnat81]

Very common over here these days. In my state you can no longer install a standard Electric Tank if there are other options available (Natural Gas, Solar, Heat Pump)

They are a bit slower to recover than an electric tank, but can operate down to -5C (This lengthens the recovery time) For that reason they reccomend you oversize the storage volume to keep up.

Our Electric Heat exchange tank is a bit over 20 years old, we dont have the space outside for a Heatpump or Gas hotwater tank to go, so we'll have to go with solar when the current one dies.

To think of its efficiency, its like comparing Heat Pump central heating to resistance electric heating, it is significantly cheaper.

 

[sudsman]

Not VERY hot water

Says it will only heat to 120 not enough for me.

 

[supersurgilator]

I just saw these in our Lowe's flyer yesterday. They are different. I tend to favor the tankless myself.

 

[brisnat81]

Hot water in Australia has to be tempered for all taps except Sink and Laundry to between 125 and 130deg.

The Heat Pumps here maintain a tank temp of 50-60degC and have no resistance element for backup.

The joy of living in a temperate climate.

 

[toggleswitch]

Placing these in a heated basement accomplishes nothing but dehumidification.

Thatt heat needs to be replaces by other sourcesm whihc, of course, costs money.

In that setting, saving are illusory.

 

[brisnat81]

Hey Steve,

Here they are only suitable for outside installation. There are some split system units that the tank can be installed inside with the compressor outside, but they arent as efficient. Some of these pump water through the outside compressor (Like Solar hotwater), others circulate the freon through piping into the tank (like a split system AC)

We know a few people that have them and with the Government rebates, they're no more expensive than a standard Electric tank to install.

 

[48bencix]

At Lowes

The GE version is on sale at Lowes for $1439.00, regular $1599.00. These units can be set at your desired temperature up to 135-140 degrees, they are set at 120 for the GE and 122 for the Rheem, at the factory for safety.

There is a federal tax rebate available for 30% of the cost which helps greatly on the pay off. If you go to the GE site and compare this unit with electric tank (typical standard unit) and gas both tank and tankless, assuming the electric rates and gas rates on the energy lables, this unit is the cheapest to operate.

Who knows how long they will last and the maintenance possibly required, other than changing the air filter for the heat pump?

Still an interesting development in the water heating field. I can imagine a retrofit for hot tubs, it would be nice to lower that bill!

 

[tomturbomatic]

The concept was introduced decades ago, I believe, but then funding was pulled from energy saving products like this and solar so that we would enrich the oil company friends of those in power. Originally these had what looked like a dehumidifier connected to the tank by hoses.

Having a heat recovery coil attached to a central air unit will heat water almost for free (except for the cost to run a small pump when the compressor is running) during the cooling season, which in some locations lasts a good part of the year. Until the water in the water heater is hot enough, it even saves the cost of running the condenser fan.