Heat Rises

In one of my recent missives, I was talking about natural convection and heat rising through a house.

This prompted a question asking whether removing loft insulation in summer was a good idea?

I think this is probably very impractical for 99% of houses, but it did get me thinking. I was in fact up in the loft space the other day and even though(as you might expect) I have a well insulated loft ther heat in the roof space was still quite high. This can be caused by two things, the obvious one is that heat is being convected into the roof space by sunlight coming on to the roof, here the insulation in the floor of the loft will act as a barrier and stop this heat going down into the house. Otherwise natural convection in the house means that through the day, heat will still find a way to rise through gaps around loft hatches and the like.

If we believe that hot air will rise and you do want to do something about this, then perhaps another alternative is to install a couple of Velux style windows in your loft. Opening these during the day, particularly later in the day, when heat has built up, would allow the heat to dissipate.

In economic terms it is probably hard to justify this investment, unless you do want daylight in your loft space, but as a theoretical muse it is worth a thought.

As a practicing energy consultant, it behoves me to have these lateral thoughts from time to time - now, how can I find an energy efficient way of dispelling heat from my greenhouse?????