Sunday, December 29, 2019

Replacing old baseboards

Will I save electricity by upgrading to newer electric baseboards?

Will replacing old baseboards save us energy? Our house is 20 years old and has electric baseboard heat. I was told by an electrician that we might want to consider getting newer baseboard heaters as they may be more energy efficient. Is this true?

Answer from Green Energy Efficient Homes

All electric heaters are 100% efficient at converting electricity to heat, regardless of how old they are, so replacing old baseboards with newer ones won’t save you any energy. The first law of thermodynamics states that energy is conserved in any process involving a thermodynamic system and its surroundings (in this case, the baseboard heaters and your house). There is nothing else for the electricity going through your baseboards to do but turn into heat. So there is no way for you to get more efficient baseboard heaters; they are all going to operate at the same 100% efficiency level in terms of converting electricity to heat.

Of course, electric heaters aren’t really that efficient, primarily because thermal power plants are typically inefficient at converting heat (coal, natural gas, nuclear) into electricity. Electricity from coal, for instance, is typically around 35% efficient at converting heat into electricity (the rest of the energy goes up the chimney stack as waste heat). Then there’s another 3-7% loss in transmission (again, electricity getting converted to heat and electromagnetic radiation). That’s why electricity is an expensive way to heat – even an average gas furnace will convert 80% or more of the energy in the natural gas into heat.

If you pay time-of-use or tiered electricity rates…


One way in which you can save on your electricity bill with a newer baseboard heater is if you buy a storage heater and you pay time of use rates for your electricity. For example, in Ontario where I live, we have a three-tier electrical rate: 4.4 cents per kilowatt hour during low use, 8.0 cents during higher use, and 9.3 cents during peak use. In the winter, the cheapest electricity is available from 9pm to 7am, with the most expensive from 7am to 11am and from 5pm to 9pm. Storage baseboard heaters can be set to convert electricity into heat during times of inexpensive electricity, store that heat in a heat sink such as ceramic brick, and release some of that heat later on when heat is needed but electricity is expensive. Another option, if your house is very well insulated, is to use a programmable thermostat to have the baseboard heaters heat the house to comfort level a couple of hours before you wake up, so that less electricity is used to heat the house during peak hours. Of course, if you have a poorly insulated house, much of this heat will escape to the out of doors so the benefits of pre-heating at a cheaper electricity rate may be undone by the heat loss to the outside.

Efficiency vs Effectiveness

The other issue to consider is the effectiveness of different types of electrical heaters. Electric heaters can distribute their heat through conduction, convection, radiation, or a combination of the three. Baseboard heaters distribute their heat through convection – they warm the air around the heating element, which creates air circulation which then spreads the heat through the room passively. Some types of portable electric heaters use radiation (shining heat directly at a solid object), which works very well for drafty rooms, while others use forced air convection, blowing the heat away from the heating element with a fan, which can result in a more even distribution of heat. One easy way to increase the effectiveness of your baseboard heaters is to make sure there is adequate circulation around them, and in fact adding a fan (for instance, a ceiling fan) to increase circulation will definitely help. The more evenly the heat is distributed through the room (rather than concentrated close to exterior walls), the more of the heat will warm you rather than escape through the walls.

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