Heating empty rooms

chris_n

I think the idea of leaving one unused room unheated for most houses will save energy. But when people are leaving multiple rooms unheated you start to create a problem where internal walls effectively become outside walls. These walls will not retain heat the same way external walls do so the heat will migrate to them anyway, so cooling the spaces you are trying to warm very quickly. Internal doors are not the same as external either, no seals etc, air will circulate around the edges.

Mstty

It would be cheaper to move, downsize and buy the most energy efficient house you can. Pocket loads of cash and go on cruises over the winter?

redbuzzard

Be careful with humidity. If relative humidity in your rooms heated to say 18C is 45%, then the dew point is about 6 degrees.  If RH at 18C is 60%, the dew point will be 10 degrees.

In an unheated room, even if it is at say 14 degrees, the surface of an outside wall can easily be cold enough to cause condensation when it is cold and windy outside.

You can do these calculations with this calculator

I would also consider getting some of these hygrometers/thermometers so you can easily see what's going on.

Condensation is a common and potentially costly problem, and I foresee a large increase in problems as more and more people cut back on heating.

Ventilation helps but the corollary to saving on heating is that people also want to block up all the holes and shut window vents.