How to keep homes cool without air conditioning

The problem may have less to do with the source of heat, but the rate of heat loss through the building envelope – specifically the walls and windows. This page explains in simple terms all about human comfort in homes -  

How to design a home for thermal comfort

Are you in an older house? Maybe one that needs but hasn’t had an energy retrofit? For perspective – A well-insulated home with good quality windows will be more comfortable, even when you aren’t close to the heat source. If you find you cool off when you step too far from a radiator, I suspect that may have more to do with how well your walls are insulated, how airtight your home is and the quality of your windows.

 I don’t want to stray too far from your actual question, but I hesitate to recommend a replacement heating system (which is not cheap), as you may not find that solution has much of an impact on comfort. Investing in energy efficient upgrades might bring greater comfort, as well as be the best bet financially into the future.  

First things first – do your radiators overheat the house then shut off for long periods of time letting the house cool down? If that is part of the problem, switching to electronic thermostats may be the best first step to take. They are more sensitive and more accurate than a bi-metal thermostat, so they will cause your radiators to cycle on and off more frequently and avoid dramatic swings in temperature. 

If that is not the problem and it really is a case of feeling cooler when you step away from the radiators, I really suspect that has more to do with building envelope issues. The most significant impact on human comfort in a home is not from the air temperature, as odd as that sounds, it is actually the radiant heat transfer between your body and the environment. Poor quality windows will suck the heat from your body, as will cold walls. We have a page about designing for thermal comfort that may help you solve and fix the problem. Air leakage is another issue that will make a home feel drafty and cool, particularly away from radiators.

But to get back to you actual question - 

• Radiant heat (floors or walls) is considered the most comfortable due to the thermal comfort explanation above. But a retrofit heating system replacement may be a very costly undertaking unless you were planning to redo your floors anyway.

• Convection heaters are basically an electric radiator with a fan, so they help distribute the heat around the home better, but with that comes air movement, which has its own effect (think inside wind chill factor).

• Installing a ceiling fan (set to draw air up not push it down) may be a cheaper and more effective solution to better distribute heat, if you can just replace an overhead light fixture with a combination light and ceiling fan.

• Forced air heat may balance heat through a home better than sparsely placed radiators, but if you have electric radiators you probably don’t have duct work, so that would be a lot of headaches and cost.

• Installing a high-efficiency wood stove or pellet stove (if local regulations don’t forbid it) might be an option to consider, though it will also offer localized heat,  so in the absence of energy efficient home upgrades you will feel cooler the further you are from it just like with your radiators.

If you do decide to undertake a renovation to increase comfort and efficiency, see our pages on renovations for some ideas, and feel free to write back with a question on that front.

This is a topic where there will always be conflicting information because there isn’t really a single right answer.

I’ll try not to get too convoluted in this answer but I can’t already tell it will be long. First thing to say in general, is that the cooler you keep your house the less energy it will use - just as the inverse is true for your fridge - although fridge organization is necessary to reduce food waste. Heat loss increases with a greater differential in temperature, so the warmer it is inside compared to outside the greater your heat loss will be.

As for where to set the temperature at night, I would make that decision based primarily on comfort and whether or not you have a thermostat timer and wake at a regular time. If you like sleeping in a cool room then drop the thermostat for sure, but if you don’t sleep well like that then keep it a bit warmer.  

How much you will benefit from lowering the temperature at night and when you’re gone depends largely on how efficient your home is and if you have a lot of thermal mass inside the building enclosure.

Lowering thermostats at night made a lot of sense 40 + years ago when homes were poorly-insulated and sometimes not insulated at all. Back then a furnace would cycle on and off many times in a day (or even in an hour) to keep the house at the designated temperature. The savings were realized because a house at 21C would lose heat a lot quicker than a house at 17C, so there was simply no point maintaining a higher temperature with the greater heat loss if no one was there.

Now that homes are much better insulated and built airtight there isn’t the same amount of energy savings to be had by varying the temperature as there isn’t as much heat loss.

So here is how you can come to your own conclusion, which will be the right one:

If your house is not very well insulated and not very airtight and the temperature falls off pretty quickly when the heat is off, yes, you would probably notice the savings by lowering the temperature a bit in the day. How much I would drop it depends on how fast it warms up again when I come home, and whether I have a ‘smart’ control or timer so I can set it to be comfortable when I return.

If you have a super-insulated house, it may take so long for the temperature to drop that it is hardly worth it.

If you have a lot of thermal mass in your house (concrete slab floor, bricks or masonry on the interior etc) it will take a long time to cool off, and consequently a long time to warm up again, so again it may not be worth it. In such a  house the savings may be negligible and the main result may be discomfort coming home to cool furniture and floors.  

If that doesn’t’ answer your question sufficiently, feel free to write back with more specific details about your heating bills and how modern or well-built your house is.