Save Energy in the Conservatory
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Most conservatories are an add-on to the original house, generally to get a bit more space without the hassle of moving. Frequently located on the sunny side of the house, they do great job of capturing the sunlight even when it’s a cold day outside.
However from an energy efficiency point of view they can be a two-edged sword.
HOW IT WORKS:
Summer:
Like in a greenhouse, the sunlight coming into a conservatory heats up the things inside it (the floor, the furniture, the dog etc). This heat then gently radiates back inside the room, giving that nice warm feeling.
However too much heat input from the sun can soon lead to overheating. What’s more because the conservatory is attached to the rest of the house it can transfer this excess heat into the house.
Winter:
Because the sunshine is much weaker in winter, it takes a lot more to heat it up. On overcast days you’ll end up with a very cold room.
However any attempt to heat it will result in extremely rapid heat loss because the conservatory is made of glass.
Basically if you were to heat a conservatory, even with the most advanced glazing you will be losing heat about five times faster than a normal room. And with less advanced glazing it can be ten times or more. This means having to use 5 – 10 times the energy for heating it than you’d need for anywhere else.
POSITIVE STEPS:
These vary depending on the season.
Summer:
Assuming a nice bit of sun, overheating can best be prevented by stopping the heat getting in in the first place.
In the summer the sun is high in the sky for most of the day, so we need to block the rays coming in through the roof as the midday sun is the strongest. This can be by blinds or appropriate drapes, but the key is to prevent the sunlight striking the floor etc and heating it up. If heated, floors can hold heat for days.
Obviously you can open windows for cool breezes, but the stopping of the heat in the first place is the best line of defence.
Some conservatories have high reflectance glass on their roofs to cut down on the amount of heat input. These can work quite well, but don’t offer the same sort of control as opening or closing a blind.
Winter:
In winter the sun is a lot lower in the sky. This means it tends to come in more through the side windows than the roof. But in winter you want to maximise the amount of solar input to make it as comfortable as possible.
This can be done by ensuring all windows that receive the sun are free of anything that might block it when it’s shining. The sun is free, so it makes sense to make the most of it. In fact these are the principles of Passive Solar heating. (If you’re interested in learning more, there's an excellent book on this, The Solar House)
As soon as winter really starts to bite and the conservatory starts feeling colder rather than warmer than the rest of the house, it’s time to shut the door. Keeping the conservatory isolated from the rest of the house during this time is a very major Carbon-saving opportunity.
Doing so will keep the warm air from the rest of the house from finding the easy way out through the glazing. It’s no overstatement that that simple act of shutting the door will increase the efficiency of your house no end.
