Browse Forums Heating, Cooling & Insulation 1 Jul 28, 2011 11:37 pm Hello all.. First post, so go easy! We have a split level home in Melbourne, which gets non stop sun in the summer months. Although we have trees on our sloped block, our roof is mostly uncovered during the hot summer days and as such our upstairs level is unbearably hot. On a 30+ day, our 2nd floor is well over 40 degrees and totally unusable. We have a 3yo who will be moved upstairs soon, and as such I have to sort out some cooling options for her asap. Our house is 7 years old, painted brick with a colorbond corrugated iron roof that has been painted light grey. We have no vents, whirlybirds (I'm told they don't always work), or any other upstairs ventilation. We do however have blanketing under the roof as well as some insulation. Although neither seems to be doing much. I'm thinking we'll need some good split system air con, but any other help/advice welcome. Thanks Trav. Re: Cooling help.. 2Jul 29, 2011 6:14 pm If you have plenty of insulation in your roof perhaps a lot of the heat is coming in through the windows. Remember heat rises so it will tend to make the upstairs hotter than downstairs. Doing something to keep the summer sun out of windows will help. First priority is North and West facing Windows followed by East Windows. You will find some advice about shading here. http://www.anewhouse.com.au/?cat=208 For upstairs windows that are north and west facing if you can't shade, I would really recommend reflective film which can make a huge difference. Shade the windows and this will reduce the amount of air conditioning you will need. A ceiling fan blowing the heat down the stairs may also help 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: Cooling help.. 3Jul 30, 2011 5:28 pm Thanks for the reply Bashworth.. Yep the main windows are North and South facing, with smaller East and West windows. The big problem is there's no cover anywhere over any part of the house. Perhaps we could add some closable external shades as another option? Then we'll put a split system in both bedrooms (2 separate ones) and hopefully that will be enough. Is there any reason to think vents with fans pulling the hot air out will help? Like Stored hot air in the roof cavity? Re: Cooling help.. 4Jul 31, 2011 4:44 pm There are other threads about veting the roof space. Generally my understnading is these are more of a help in cooling things down after dark than during the day. As I mentioned in my early reply If you can't shade you will be surprised how much difference reflective film can make without making the rooms too dark. It worked for me! 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: Cooling help.. 5Aug 22, 2011 11:52 pm External shades are a more flexible solution. Film also blocks useful sun in winter. Re: Cooling help.. 6Aug 23, 2011 8:03 am For the north windows, place a horizontal shade above the window such that it blocks summer sun and allows winter sunlight to enter. You can get the required overhang from http://www.yourhome.gov.au/technical/fs46.html Then vent the top floor. A vent + pipe through the roof with a cap. No need for a fan as the hot air will naturally vent out. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Cooling help.. 8Sep 06, 2011 12:20 pm traveller I'm going to put some external open/closeable vents as a start. Casa2, will this cap prevent heat escaping in winter? Also will it still work if I also add some split system air con upstairs too? The external vents will be great in summer and help a little in winter. Interior curtains with close fit pelmets will be a great boost for winter. The split system airconditioning will work well upstairs. The first trick is to get the temperature swings down as much as possible. Use evey possible passive heating and cooling technique that you can readily add. This will make the house more comfortable. Finally add the air conditioning, which won't have to work all that hard or all that often. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Cooling help.. 9Sep 18, 2011 11:24 am Anyone used anything like these.. http://westernsolar.com.au/sv-20-2/ Or these.. http://www.edmonds.com.au/Products/Resi ... -Vent.aspx Or these.. http://universaltileventilators.com.au/ ... -vent.html Trav. Re: Cooling help.. 10Sep 19, 2011 10:49 am Ok my plan is this.. I'll install some vents (with caps) directly out of the 2 bedrooms and hall space on my top floor. This will allow the hot air which is currently stuck up there, to escape, and keep the hot air in during winter. I will also vent the roof cavity with a couple of vents to reduce the hot air stored up there. Something like the smoothline ventilators. Then I will add some closable shutters for the bedroom windows or possibly some angled shading. After that we can then add some split system air con for the super hot days. Does that make sense to the experts here? Trav. Re: Cooling help.. 11Sep 20, 2011 9:01 pm Hi Trav. The vents (with caps) are a good idea. They will let the hot air trapped in the upper floors out. I'm not sure if the roof cavity needs to be vented. If you have sarking and insulation then the roof cavity shouldn't get too hot. This is easily tested by going up into the roof on a hot day. Even if it's 10 degrees hotter up there than inside, a good layer of ceiling insulation would provide sufficient protection. The main thing it to prevent sunlight entering the house during summer. Proper external window overhangs on the north side and external shutters on the west side are best. The next good things are thermal mass inside the house and good cross flow ventilation. The cross flow ventilation is only opened up when the outside temperature drops below the inside temperature in the late afternoon. Keeping the house ventilated until sunrise will mean the house starts the day off as cool as it can. Hard to add thermal mass into an existing house, but just thought I'd mention it for completeness. Once these are done, your maximum temperature will be much lower. Aim for 10 degrees lower than otherwise. Main thing, don't let direct sunlight get into the house (block it externally). Keep the house closed up early in the day and only ventilate when the outside temperature is below the inside temperature and falling (use a thermometer - don't rely on feel as it will feel colder outside due to air movement even though it's hotter. While on the subject of air movement, fans are an inexpensive low energy method of keeping cooler, particularly ceiling fans. Finally, some split system airconditionners to bridge the gap to a comfortable temperature range. Let me know if you'd like to know more. Cheers, Casa Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Cooling help.. 13Oct 02, 2011 9:00 pm I don't think the roof colour is a big deal. There are many other areas much more important such as sarking and insulation. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Cooling help.. 14Oct 07, 2011 8:44 am Unfortunately part of the ceiling in the upstairs rooms is right on the roofline, so no room for regular insulation up there. Perhaps we could pump some insulation foam in.. http://www.ecofoamwallinsulation.com.au/ Anyone used this type of insulation? Re: Cooling help.. 15Oct 07, 2011 9:47 am traveller Unfortunately part of the ceiling in the upstairs rooms is right on the roofline, so no room for regular insulation up there. Perhaps we could pump some insulation foam in.. http://www.ecofoamwallinsulation.com.au/ Anyone used this type of insulation? Looks good traveller - had a read of it. I would use it in your situation. Suburbia is where the developer bulldozes out the trees, then names the streets after them. Hi there, long-time lurker but first time posting. I've bought a house 2 and a bit years ago and last year we had some major water damage on a converted pergola area… 0 7931 Yes, unless you are in a low intensity rainfall area or the area is protected from rain. Do you have access to NCC Part 2 or can you download it? I can email you a copy… 10 12512 Thankyou so much 😀 I've decided on White on white for doors and trims, White on white 50% on ceiling and Mt buller for walls. Fingers crossed it will look OK 😀 2 7158 |