I’m always looking to make my home more energy efficient to use less power and save money, and with that in mind I took a hard look at our use of hot water. In the last few years, some excellent heat pump water heaters such as the Rheem hybrid series have become available that provide an order of magnitude improvement in power consumption. If you are replacing your water heater, I highly recommend you take a look at these and take advantage of the local rebate programs (up to $500 in Seattle.) These new water heaters draw heat from the air and transfer it to the water, much like our home heating system, and can save you an estimated $450 per year in electricity costs. There are also tankless solutions that are energy star rated, and these may make sense if you are installing more than one water heater and have a long distance between your water tank and your shower. Whatever you do, you should take a look at the efficiency rating table from EnergyStar.gov.
If you’re working on an upgrade, you should also look into drain water heat recovery (DHR) solutions. These systems are a set of copper coils that wrap around your drainpipe. When you are using hot water, the water being drawn into your water heater first passes around the drain pipe, transferring heat from the water being drained to the water going into the heater. The two most popular solutions are Ecodrain (reviewed here), Watercycles . DHR is now required in all new construction in Canada, and is really a no-brainer you are already doing plumbing work – the payback period from energy savings is estimated at 5-7 years.
While I looked into these products, I’ve decided to delay replacing my water heating system because it’s a big cash outlay and the water heating tank that came with the house is a relatively efficient and high quality electric water heater. They last for about 10 years on average, so I’ll be replacing my system with a new heat pump water tank in 2023, which will perhaps be connected to a DHR solution.
If you aren’t ready to replace your water tank and spend a heap of cash, there are some cheap and easy ways to save energy and money. One of the best things you can do in terms of return on time and money is to buy and install a watersense rated showerhead.The EPA estimates that the average household will save 300 kwh (enough to power a home for 11 days) and 2,700 gallons of water per year by installing watersense showerheads. These are generally quite cheap to buy (starting around $6) and take around 5 minutes to install. You’ll need a wrench and some plumbers tape – and that’s all. I actually got sent one of these for free with my rebate for installing an efficient fireplace.
You can also buy watersense inserts for your bathroom sink, which is another cheap and easy way to save water.
The second thing I did was insulate my water heater. This took about 2 hours and the kit that I bought cost around $35. The EPA estimates that this can cut your standby heat losses by 25-45% and save 7-16% on the electricity used to heat your water. The payback period is about a year.
Before: My electric water tank.
When insulating your water heater, it’s important to remember not to cover the area around the electrical connection (the silver casing pipe in my case) and to leave an opening to access the controls and the drain valve (remember to flush out the system once a year.) The new Rheem heaters have wireless connections that allow you to change the mode when you go on vacation or need extra hot water. Mine requires a screwdriver.
While I do everything I can to use renewable electricity, it’s important to remember that electricity comes from the grid, and any energy you forgo reduces greenhouse gas emissions from natural gas and coal elsewhere. Cutting your power use makes a lot of sense both for the environment and for your own personal finances. You can do this by opting for only energy star rated products when replacing your big ticket appliances, doing a good job with your insulation, and through little projects like this one.