why the climahouse cube doesn’t work

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Have you ever seen the bet of the Climahouse cube ?

Two ice cubes are placed in the middle of a square exposed to the sun in summer. The first one is exposed to air while the second is protected by a shell of polystyrene to simulate a perfectly thermally insulated building.

After a month the two ice blocks are compared and it turns out that the second wrapped by Styrofoam is intact while the first has melted “like snow”.

The aim would be to demonstrate the advantage of very isolated buildings and the cottage built for the experiment -so ClimaHouse agency- simulates a ClimaHouse.

However, there is a but.

The simulation omits some details, rather starts from the wrong assumptions.

First into the house there is not a source of cold, but people. And people produce heat*, which combines the warmth of the light* and appliances.

* (A person emits approx. 100 thermal watts, filament lamps have an efficiency of 3%, ie 100W lamps produce 97Watt thermal and only 3W light.)

In addition, the houses have windows. Light enters through the windows and sometimes even the sun, and that warms the rooms!

Moreover, sometimes the doors and windows are open, if only to refresh the air.

Also the legislation requires for the calculation of the dispersions to take into account a change of air of 0.3-0.5 volumes / hour. As say: within 2, at most 3 hours all the indoor air is exchanged with the outside air.

So if the air outside is hot, in 3 hours or less also the air inside the house will warm up . And the temperature will be even hotter than outside, because inside there are people, lighting appliances and solar gains.

Then it would melt first the insulated cube of the discovered one.

While people would gladly go out of the house!