It has been a hot week in the UK (at least by our standards) and for most of Europe it seems. I have been out doing energy surveys every day, and despite sweltering and having aching feet from all the walking, I love to see how buildings perform under peak conditions.
The UK has a relatively mild climate. Being surrounded by sea and benefiting from the warm Gulf Stream, means that our winters and summers are not as extreme as for mainland Europe. This is reflected in the design of our buildings. For instance French buildings traditionally have shutters. These aren't purely decorative, but have a functional purpose, to prevent solar gain. When the sun shines in through the window, it heats the building up like a greenhouse. The shutters on the outside of the house are more effective than blinds, because they stop the sun's rays before they get inside.
|Typical French shuttered windows|
|Traditionally English townhouses were close together, providing a shady walkway|
|Aptly named 'Thrift House' with the curtains drawn|
|Glass greenhouses in central London ;-)|
3. Open your windows at night (if you can without inviting burglars) or early in the morning for an hour or two, to help flush out the warm air and allow the building fabric to cool down again. The bricks, concrete, tiles, fixtures and fittings all retain heat. so often you will find that when the air outside has cooled, the building still feels warm on the inside. You can use the cooler morning air to purge the heat, so that you start the day with a cool building. I throw open the windows at 6:30am, before everyone else is up, and once the stone tiles on my kitchen floor feel cold again, I shut my windows against the rising temperature outside. This helps the house to stay cooler for longer.
4. Every appliance that is switched on, from a light to a mobile phone charger, will be kicking out waste heat, into your lovely cool building, so make sure that everything possible is switched off. Fridges and freezers may be keeping the food cool, but in doing so they kick out a lot of heat from the coils at the back, which is adding to the heat in your house. The higher the air temperature the harder they have to work and the more heat is emitted, so try not to open them unnecessarily. You could also try using timers to run dishwashers or breadmakers in the early hours of the morning when it is cooler (unless you have PV panels and want to make use of the solar energy).
|Landline phone that only works when it is plugged in|
5. If you get to the point where it is too hot inside and you need to get a breeze going to help cool you down, then remember to get a crossflow of air. This means trying to open windows or rooflights on at least 2 faces of the building, with an open flow between them. Heat tends to rise, so it will gather at high points. Opening a rooflight or upstairs window will allow the hottest air to escape, whilst opening a window on a lower level will draw in cooler air to replace it. I have seen lots of hot offices this week where the office windows are open, but the office door is kept shut for privacy. This means that the air cannot flow across the building, so the occupants don't benefit from getting a breeze from their windows.
6. Putting a fan near your window can help to draw in fresh air from outside, but if the air outside is hot already then it makes more sense to aim the fan at you. A fan blows air across your body, encouraging the heat to transfer from your hot skin to the marginally cooler air. Hence it makes you feel cooler.
|Trees for company|
|Stone house surrounded by trees for shade and cooling|
9. Hot air rises, so if you are having trouble sleeping in your bedroom upstairs, then camp out on the ground floor or even in the basement if you have one. This will help you stay cool and get a good nights rest.
10. I heard on the radio today (for the first time) an advertisement for air-conditioning for homes and it made me groan. Air-conditioning is expensive and uses a lot of electricity to provide you with artificial cooling, so please try some of the cheap and easy methods to stay cool first. If you are a 'battery-farmed' office worker, in a large open plan office with only a couple of square metres of space, then the chances are that you will have cooling provided, and on a hot day it will be working flat out. If you can, take this opportunity to request to work from home. The less bodies in the office and computers in use, the less heat is being produced. This will save energy, reduce the load on the air-conditioning and help everyone to stay cooler.
Remember to always switch air-conditioning off in an empty room and to keep windows shut whilst it is in use, otherwise your expensive chilled air will be escaping. How many of you have walked past an open shop door and felt the rush of cooled air coming from within?
You may already do all of these things, but hopefully someone may find the odd tip helpful. Hope you have a lovely sunny summer where you are, with a nice cool house to retreat into when it gets too hot :-)