Why does the house get so hot at night?

[garym999]

Loads of trains of thought to follow. House is heated by conventional radiators but of course this time of the year are not needed. The front of the house with three of the bedrooms faces SE and the rear with one bedroom, ensuite and bathroom faces NW with a nice big red brick wall facing SW. So do I assume that it is this wall that is collecting all the heat? If this is the case I also guess there is very little I can do about it as I do not want to paint it White.

Another train of thought was heat travel via the loftspace. It is of conventional construction with the cavities open at the top where the roof is resting. Could the heat be rising out of the cavity at night in to the loft space and then building up?

[Aidan]

Could be. So is it most pronounced after a day of sunshine? We haven't had much of that recently, where is it? Barbados? I'd have thought the wall insulation should reduce it, most similar houses don't suffer from this, so I'd suspect there's something else going on, defective cavity insulation or something. Any neighbours similarly afflicted?

Possible, then the loft would be even hotter than the rooms. A thermometer with a remote sensor element would allow you measure what's going on up there. Is the cavity ventilated with airbricks at the bottom? Hot air won't convect out the top unless there's cold air going in at the bottom.

If so, shouldn't these be ducted through to ventilate the floor cavity? Builder chaps please advise.

[garym999]

Barbados AKA Oxfordshire. The house is one of two and we face the sun and sheild the neighbours. The cavity has weep vents all aound and two air bricks to the lounge for the fireplace. These are lined with a sleeve but not sealed did wonder about sealing these with expanding foam.

[Doctor Drivel]

It keeps the heat radiating from the hot loft.

[Steve Walker]

leave open the loft hatch at night - hot air will all zoom upwards

[meow2222]

I'm sure you understood what was said really.

bingo

yes, but most of us live in brick or block. Anyone living in a wooden shed is out of luck.

NT

[meow2222]

...one thing i didnt mention before is it needs a lot of airflow for many hours, but given that it works nicely.

NT