Sunday, February 5, 2012

Water Heating

Since water heating can range from 12% to 25% of household energy use lets begin our focus here. It is possible today to cut this cost by 2/3rds with the help of a heat pump water heater. If you are replacing an existing electric water heater you will see a substational savings in your electric usage.  GE claims $320/year.

Currently there are a couple of options:
#1 Installing a GE Hybrid water heater.
This unit uses both resistence elements and a heat-pump to achieve maximum efficiency and better overall performance.

#2 Installing an add-on heat pump to your existing water heater.
While sold as a retrofit...This unit can be difficult to install for the average do-it-yourself person. The retrofit also disables the electric elements so there is a total reliance on the heat-pump for fast recovery and/or problems of placement in an unheated room. It however does a nice job of dehumidification. This manufacture also offers a hybrid unit.

We have one of the air tap units installed in our two person home and have enjoyed the energy savings. It is installed in our basement and has performed beautifully. I did however leave the electric elements hooked up and I connected them to a room thermostat so that if the temperature in the room got below 50 degrees they would be used to speed recovery of  hot water without depleting the space of heat. Not difficult to do but it further discourages a DIY project.

We have also been involved with the installation of the GE unit in a two person home and they have seen substantial energy savings.

- Dehumidification and cooling of room they are in
- Most efficient for 2 person households
- Low wattage requirement over 100% electric
- A must do if you are adding solar to your home and you have an electric water heater

- Savings are based on household size and usages
- Cooling of room they are in
- Long recovery time
- Compressor and fan noise
- High upfront cost
- Cannot be installed in small closed off room

Other ways to cut water heating costs:
- Cold water wash
- Low flow shower heads
- Water heater sizing
- Water heater & pipe insulation
- On demand water heater