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Some things you should know about building efficiency...
One of the principals of heat transfer is heat always goes from hot to cold. Always. Some people think heat rises but this is not true. If it were, then the earth (preferably the side you're standing on) would always have to be above the sun. When you put it in those
terms heat rising becomes a silly thought, agree?
There are other ways to think about everyday heat transfer. Ask yourself why you feel cool in the supermarket freezer section or underground parkade on a hot summer day.
The reason why you feel cool in the freezer section or parkade is your blood is much warmer than the cold display glass or concrete walls so the heat from your body travels via radiation from the skin which is heated by your blood, to the cooler surfaces.
Do you know what physicians and building scientists call this sensation?
That's right, its called
radiant cooling.
Designers can provide radiant cooling by sending chilled water through PEX pipes located in the floor, wall or ceiling just like a radiant heating system.
In fact, a radiant floor used for heating and cooling is called a reversible floor.
Click on the image below. Can you imagine that the
PEX pipes might represent your arteries and veins. Can you see how a radiant heating and cooling systems is almost like
your body?
Photo Credit: NRDC,
Click to enlarge.
One of the major methods your body regulates its internal temperature is by the flow of blood to the skin.
When your body is exposed to a warmer surface it absorbs energy in the form of heat which makes you feel warmer.
When your body is exposed to a cooler surface you release energy which takes away heat which makes you feel cooler.
A warmer or cooler surface in a building is based on its energy efficiency and/or by "conditioning" the surfaces with PEX pipes or other forms of radiators.
The less efficient a building the greater the temperature difference between your skin and the temperatures of the walls, windows, doors floors and ceilings.
It is the temperature differences which causes discomfort.
That's why conditioning surface temperature is so important in the comfort equation.
Its why this front entrance will feel cool. Image how it would feel if it didn't have radiant heating to compensate for the losses.
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