Cooling upstairs of a house

[Rick Hughes]

A couple of years back I posted a question .. didn't get very far, thought I'd try again.

I have a modern highly insulated 2 storey house, and this time of year the upstairs get very hot .... and with high values of insulation it does not cool quickly ... bedrooms are very hot.

In the US they have a very good solution "Whole-House fans" when temp drops outside in the evening you switch these on, being fitted on upstairs ceiling it vents the warmest air in the house into attic space, this air then being replaced by air form downstairs windows being put in vent position. Explanation video & installation video on this page:

I have been unable to find a manufacturer in Europe .... anybody out there know of one ? Getting fans & remote control would not be difficult, but having 'actuating motors that open the insulated doors would appear a lot more problematic.

Welcome comments from anyone who may have looked into this.

I could buy the US items and run off a 220 - 110V converter .. but it would not be cheap to ship over plus 20% VAT on import.

[Jabba]

Rick Hughes scribbled...

Not looking in the right place ?

[Martin Brown]

That isn't right then. Is it ingress of heat from the roof or trapping heat in the rooms from the sun coming through the bedroom windows?

[The Other Mike]

Leave a couple of upstairs windows open on different sides of the house.

Keep curtains closed on the sunny side of the house

Cross ventilate the loft space with a large slow running fan

Add overhangs to the windows so you only get solar gain in spring autumn and winter

Reflective coatings on the glass

[Davey]

The fan we had in a rented house in Kansas City had louvres that were spring loaded, or even maybe gravity operated, and they just opened when the fan began sucking air. No actuators required.

The fan was wonderful, even though it sounded like a jet taking off, but it didn't need to be on for long.

[The Natural Philosopher]

One option is install a LOT of thermal mass and draw the curtains by day and open the windows by night.

[Toby]

On my list of things to do, is to mount a large fan into a spare loft hatch, and then just slot this into place in the summer, and run when required - this might be an easier approach!

[Andrew Gabriel]

Well known problem with many modern houses - they have no internal heat capacity, and so only a small amount of energy getting in causes a significant temperature rise. Lack of loft insulation would make it very bad (radiating heat from the hot ceiling), but even with loft insulation, it can be a major problem.

I have two loft hatches - the summer one has a 10" Expelair fan mounted in it. This was originally done for another reason - I had some computers in there when I worked for Sun, and it was to try and stop the temperature up there climbing over 40C. Computers long since gone, but I still use it to help cool the upstairs if it gets hot.

[Rick Hughes]

Unfortunately no ..... I already have a full whole house heat recovery system ... which is what this unit is part of. Works very well, includes 4 stage filtration including electrostatic .. other than when hot ... then it does not bring in enough cool air even on high speed.

I have this system ...

using this heat exchanger unit:

The original design allowed for addition of a 'cooling' module to cool incoming air (not air-con just allowing several degree temp drop)

The company never produced the module though.

[Rick Hughes]

Heat from downstairs rises .. so all heat gain during day ... ends up 'upstairs' even though Pilk-K glass used throughout, still a lot of heat gain.

You can feel significant difference walking form downstairs to upstairs ... only when it has been really hot day .. and house been soaking up sun.

[Rick Hughes]

I have very high levels of wall & loft insulation (sprayed in 450mm Warmcell) The issue is as you say it gains heat during the day and being Timberframe internal (brick external) it does not lose heat easily.

The outerwalls are also like huge heatsinks ...walk past outer S & W wall in evening after sunny day and wall is putting out tons of heat ... I know this is outside, but it does mean warm inside rooms even more difficult to lose heat.

The fan on loft hatch is almost same thing .... just whole house fans take it a little further with opening shutters & remote speed control

The only loft access is ion sons bedroom he may not like noise of fan .. so a ceiling mounted extract above stairwell may be answer.

[Rick Hughes]

with whole house ventilation not supposed to do this as it unbalances the system.

eE do, plus blinds fitted

Not sure that would have much effect due to high levels of insulation in loft

all glass is K-Glass

[Rick Hughes]

That is my thought, put it on at sundown .. and run it long enough to vent the layer of hot air.

[Rick Hughes]

Timber frame ... so the opposite is in this build

[Martin Brown]

Grow ivy or climbing plants up the S & SW facing sides?

Install external shutters on the windows... or roller blinds.

[The Natural Philosopher]

timber frame here too. BUT a lot of masonry fireplaces small windows and overhanging eaves.

[Capitol]

Why not fit an air conditioner to one of the rooms? With the doors open it will cool quite a large area.

[gremlin_95]

We recently had the 9 inch solid walls of our house insulated with 90mm EPS board and finished with the light weight render. We never really had any overheating problems prior to this but everyone has noticed the house is much cooler! Whether 9 inch solid walls are classed as 'a lot' of thermal mass I don't know but we certainly notice it is cooler than other houses that have the insulation applied internally or are of a different construction.

[Davey]

How was that going to work? Evaporation of water? Known colloquially in industry as a Swamp Cooler, as it cooled the air while raising the humidity. Only worth doing in dry areas, in which the UK is not included. Arizona is a decent bet.

[Rick Hughes]

This was a going to be a powered cooler ... compressor based I assume based of 2.5Kw expected current draw.

What was unclear was where teh waste hot air was going (assume loft space)