Has anybody got experience of installing a roof ventilator?

 

Was it effective at removing heat in the roof space and the house?

Have you had issues with water ingress since installation?

I installed one in our last house to ventilate the hot air in the roof space above the kitchen. Worked a bit but nothing dramatic.

 

All these ideas do help in reducing the heat but they will not actually make your house cool. Cooler.....yes ....but short of cool. That house was a 3 bedroomed terrace. So no sun on side walls. Had front and rear extension so no direct sunlight hitting walls front and back. Nonetheless , by 1 pm it will still rise to about 30 in the downstairs living room when it was 38 or 39 outside. Finally had to get another aircon unit for downstairs as couldn't spend all day in the bedroom.

 

Meanwhile , in the UK they have just had a ' toasty ' bank holiday weekend at 24C....hottest day this year so far.

11 minutes ago, Denim said:

I installed one in our last house to ventilate the hot air in the roof space above the kitchen. Worked a bit but nothing dramatic.

 

All these ideas do help in reducing the heat but they will not actually make your house cool. Cooler.....yes ....but short of cool. That house was a 3 bedroomed terrace. So no sun on side walls. Had front and rear extension so no direct sunlight hitting walls front and back. Nonetheless , by 1 pm it will still rise to about 30 in the downstairs living room when it was 38 or 39 outside. Finally had to get another aircon unit for downstairs as couldn't spend all day in the bedroom.

 

Meanwhile , in the UK they have just had a ' toasty ' bank holiday weekend at 24C....hottest day this year so far.

Thanks for that, very helpful. UK is OK in Spring. 

Little to no benefit. In the Thai climate, much better to put in an uninsulated radiant heat barrier. I did this in a place in the Philippines and it was actually cool in the attic and the top floor was significantly cooler than before installation.

This is now the standard construction technique in the hot southern US states. 

My friend has one installed, but his is fitted with trunking down through to his ceiling, he has had to fit a Mozzy screen on the ceiling (removable) and every so often spray WD 40 up to the bearings to stop it squeaking and rattling. Not worth the effort IMO.

They look the part, but at the same time they are just a hole in the roof, the spinning around does nothing in the way of removing hot air - it's simple physics of "hot air rises" - the only benefit seems to be they keep the rain out. You could achieve then result with a pipe protruding thru' the roof with hood over the top to exclude rain. 

 

To reduce heat in the roof space and its transmission into and thru' the ceiling is a reflective barrier  under the roofing material and insulation on upper side of the ceiling.