Browse Forums Heating, Cooling & Insulation 1 Dec 19, 2013 3:57 pm Hi, I have a new townhouse I built with a small 8sqm 'retreat' on the top storey that gets stupidly hot due to a west facing fixed window. I should have installed a window I could open, but that's too late now.
The rest of the house is well insulated, so it's only this area of the house which is very hot. On a 30 deg day, it could be 20 deg downstairs and 40 in the upper storey area. I have a man hole above the hot area, and directly above the hot area is a whirlybird. I installed a whirlybird as I have a small roof cavity, thick insulation batts in the ceiling and foil sarking, so I didn't wan't moisture to build up when using the bathroom. I have heard about the effectiveness of whirlybirds for heat, but due to the sarking thought it would be a good idea to install one as the bathroom vents in the roof cavity. Now I was thinking, would it be a good idea to leave the manhold open over summer to vent the hot air out and draw the cooler air from downstairs (using the theory of hot air rising). My only concern is the dust may fall from the ceiling (shouldn't be too much as it's a new house and I have sarking). Would it help at all with the heat? Any negatives (apart from an ugly hole in the ceiling)? Re: Leaving man hole open to cool down area? 3Dec 19, 2013 6:36 pm Get some reflective film on the window. It will make a big difference. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Leaving man hole open to cool down area? 4Dec 19, 2013 7:07 pm It should help. Enough? I don't know. If it were me I'd look to fix it properly, replace the window with an opening one and also add some sort of external shade as well cos it faces west. I don't know but is it legal to build habitable rooms without openable windows, and bathroom fans venting into roof space with sarking? It's good that you have installed the whirlybird but I don't think that ought to be the only thing your looking at for a solution to the heat. Re: Leaving man hole open to cool down area? 5Dec 20, 2013 11:11 am It is a habitable room? 50/50% I say as it's only a small area around the staircase to lead you to the bathroom and bedrooms. I'm pretty sure it's legal to vent the bathroom fan into the roof cavity. You don't even need a vent or whirlybird, but I added on anyway for peace of mind in winter. bashworth- that's a good idea. The only issue is getting access to the window as it's fairly high up above the stair case. Hopefully the have a scaffold in place. Can anyone recommend a window tinting company in Melbourne's eastern suburbs? Re: Leaving man hole open to cool down area? 6Dec 20, 2013 11:37 am Previously I've just used a local Tint-A-Car franchise. Ask for the most reflective film, (not the darkest tint) it will cut out around 70-80% of the heat coming through the windows. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Leaving man hole open to cool down area? 7Dec 20, 2013 12:03 pm JB1 It is a habitable room? 50/50% I say as it's only a small area around the staircase to lead you to the bathroom and bedrooms. I'm pretty sure it's legal to vent the bathroom fan into the roof cavity. You don't even need a vent or whirlybird, but I added on anyway for peace of mind in winter. bashworth- that's a good idea. The only issue is getting access to the window as it's fairly high up above the stair case. Hopefully the have a scaffold in place. Can anyone recommend a window tinting company in Melbourne's eastern suburbs? Oh, so it's just the landing? Yeah, spose that doesn't count as a habitable room. I still reckon there's some rule about having to vent a bathroom right outside if the roof is colorbond or has sarking, or if there isn't there ought to be otherwise where does it go? But that's a side issue, your wanting to fix the heat. Re: Leaving man hole open to cool down area? 8Dec 20, 2013 1:26 pm I'm going to test this theory by replacing the manhole cover with some flyscreen and see what happens. I got one quote already which was $300 (their minimum charge per job). I asked them how much for 2 windows (same size) and they said $350 for two. Unfortunately I don't want reflective tint elsewhere and this window is my only west facing window. I'm hoping to find someone with a lower minimum fee. bashworth- yes, I understand the difference. I would prefer the lightest tint with the most reflective properties, if you could get such a thing. Re: Leaving man hole open to cool down area? 9Dec 21, 2013 9:38 am JB1 . . I would prefer the lightest tint with the most reflective properties, if you could get such a thing. Is the most reflective the one that looks like a mirror outside? Birdstrike risk. Re: Leaving man hole open to cool down area? 10Dec 21, 2013 1:34 pm I'd fix some kind of external shade/awning if possible. It would pretty much solve the problem wouldn't it? Although you'd still have the rising hot air from downstairs. Build thread: viewtopic.php?f=31&t=65085 Re: Leaving man hole open to cool down area? 11Dec 21, 2013 1:41 pm EmyN I'd fix some kind of external shade/awning if possible. It would pretty much solve the problem wouldn't it? Although you'd still have the rising hot air from downstairs. Yeah, I agree, you want to do something to shade the window AND to do something to vent the rising hot air. Re: Leaving man hole open to cool down area? 12Dec 22, 2013 11:55 am I do this all the time in a single story home. Just leave a window down stairs open and it will keep the air moving upwards out the whirly bird. Try light incense and put it near the window and you can see the smoke going up throughout the building. CDC Housing Code 3 When to apply Floor Area external face of wall vs Gross Floor Area internal face of wall. Reading thru CDC Housing Code 3, lets take a lot 915sqm.… 0 16537 can’t tell from the photo, a tie down rod will be 12mm, is it a steel beam? he should be able to work it out 1 4444 Thanks for your advice. So far i have not noticed any issues with doors and windows. Builder advised they will organise drainers to inspect 2 weeks ago but no further… 7 17883 |