One of the most overlooked energy expenditures in the home is the water heater. When thinking about energy consumption, we tend to think of the obvious things around the house – lighting, heating, air conditioning, major appliances, etc. However, water heating alone accounts for up to 15% of your energy expenditures.
Because the lifespan of a hot water heater is between 10 and 15 years, purchasing an energy efficient model is of the utmost importance, as you will be living with your decision for quite some time. Sadly, many hot water heaters are replaced in times of emergency and energy efficiency is often not a consideration.
Fortunately, manufacturers have not overlooked this fact and have continued to improve water heating efficiency. Today’s water heaters are about 18% more efficient than older models. The greater efficiency can be attributed to better insulation; meaning less heat is lost during water heating.
When your old water heat breaks, it isn’t likely you will be able to replace it with the same model. Instead, your new water heater will be an energy efficient one almost by default and could save you more than $150 over the course of its life.
Replacing your water heater comes with many decisions, the most obvious of which is to buy a gas model or an electric model. This will depend largely on what type of model your current water heater is. If you do not have a natural gas outlet in your home, you will likely be limited to an electric one.
If you are fortunate enough to have an electric water heater and a gas stove or furnace, you may be in luck and have both options available. Simply extend the gas line to your water heater and you now have options. This of course begs with question – which is better, gas or electric?
This depends on a few things, including the price of electricity and natural gas in your area, and even the availability of both. Rural areas are not likely to have natural gas service, but propane may be an even less expensive option. However, generally speaking natural gas units will cost you the least amount of money. The reason is that gas water heaters work quicker than larger sized models of electric ones. For example, a 40 gallon gas water heater can turn out as much or more hot water in an hour than a 65 gallon electric water heater.
Solar hot water systems are increasing in popularity, especially in sunny regions, mostly for heating swimming pools. Solar hot water systems use an insulated storage tank and solar collectors. They can be either active or passive systems. Active systems have circulating pumps and controls, whereas passive systems do not. Making the switch from electricity to solar water heating could save up to $500 in the first year of operation alone. The entire system would pay for itself in 4-7 years. To find out more, please visit our solar water heating systems page.
Other than the heating source, there are other options you need to consider – tank, or no tank? Tankless, or On-demand water heaters, provide hot water when and where you need it without the tank. Tankless systems are available using electricity, gas or propane heating sources and save 10-20% on your water heating bill by eliminating standby losses, usually in the pipes. However, these types of systems are not suitable for a large family. For more information, please visit our On Demand Water Heater page.
The final option you have is the hot pump water system. This relatively new technology uses electricity to move heat from one place to another instead of generating it directly, making it 2-3 times more energy efficient than conventional electric systems. The heat pumps work in a similar manner as a refrigerator, except in reverse.
Regardless of the type of system you choose, there are a few other things you need to consider including Size, First Hour Rating and Energy Rating. The size of hot water heater you require will vary depending on the number of bathrooms and bedrooms (or family members) you have in your home. For reference, a 180-litre (40 gallon) tank is appropriate for a family of four. However, this is not the most accurate way to determine the size of water heater you need. A better method is using the First Hour Rating.
he First Hour rating is an estimate of how much hot water is required during the busiest hour. Use the chart below as a guide. Assuming the above family of 4 lives in a 3 bedroom home with 2 bathrooms, they would need a water heater with aa First Hour Rating of 72. You can find this rating on the EnerGuide label when purchasing the new water heater.
|How many bathrooms?
||1 to 1.5
||2 to 2.5
||3 to 3.5
|How many bedrooms?
||1 - 2 - 3
||2 - 3 - 4 - 5
||3 - 4 - 5
|You need a First Hour Rating of:
||43 - 60 - 60
||60 - 70 - 72 - 90
||72 - 82 - 90
The final thing to consider is the Energy Factor. The higher the Energy Factor, the more efficient the water heater. Generally speaking, electric water heaters have an Energy Factor range from 0.75 to 0.95, whereas gas water heaters have energy factors between 0.5 and 0.7. This would indicate that electric models are more efficient than gas models, which is true. This is due to the heat loss associated with gas heaters. However, electricity costs are about 3 times more than gas, so technically it is still cheaper than electricity. And this is likely to continue to improve, as newer gas models feature more efficient combustion, meaning less gas is needed to heat the water.