Browse Forums Eco Living 1 Jun 06, 2014 5:20 pm Hi, I'm building a house in Sydney (as an extra floor on an existing house) and want to design it on passive solar principles. I'm new here from the UK, so don't know the climate very well (but liking what I've seen so far!) so not sure how much passive or active heating I may want in winter (Does it ever get cold?) The living space is north facing with lots of glass, and a deck area outside it. The house is built on a suspended slab so will have some thermal mass. Should I keep this exposed or will bamboo floor be OK? Do I want big eaves on the North side, or an adjustable canopy, or sailcloth or a louvred canopy? And what about the East & West (which obviously have smaller windows) - big eaves or moveable canopy, or.....? Thanks! Mike (Posted this in the wrong forum before - now moved it here.) Re: Passive Solar Design in Sydney 2Jun 07, 2014 12:11 pm Really depends where you are in Sydney, ie. your proximity to the coast.
My parents are very close to the ocean, & require no heating or cooling (they have ducted reverse cycle ac, but virtually never use it). But they are in a second storey apartment, with N glazing to the living areas (plus S glazing for cross ventilation), no E or W glazing (apartments to these sides - which would help insulate). Alternatively, my sister, who is only 10km inland, has very high heating needs (they have a massive gas heater). Substantially cooler nights than my parents (though still warmer than much of Sydney). But a very poorly designed house, open plan with no way to zone areas, & a staircase that acts like a chimney. A high proportion of glazing in the S facing living areas, not much N glazing, high amounts of thermal mass which receives no sunshine (double brick construction). It would be freezing there this weekend! So, same as anywhere. Heating & cooling loads will depend on your location (proximity to the coast & elevation), the design of the house (you've got it sorted with passive solar), construction methods & standards. But most of Sydney doesn't require too much heating or cooling for a well designed property. Though I like it a lot, hydronic isn't very popular here (unlike in the UK), & it's way over priced, so would be overkill here if cost is a consideration. Gas is reasonably cheap to run (though it's only going to get more expensive), not very green, & won't help with cooling needs. I'd probably recommend efficient reverse cycle air conditioning, particularly ductless mini splits (if you can get past their looks). If you're right near the coast don't go overboard with thermal mass. Makes it harder to cool the place on hot summer nights. But for most Sydney locations it would be advantageous to leave the thermal mass floor exposed in the N facing living areas. I believe for Sydney's latitude 900mm is the optimal eave width, for due N orientation, but don't quote me on it. Don't go too big with N eaves, or you'll limit passive heating. Adjustable awnings are great, just to tweak your passive heating. Particularly when you consider the earth's seasonal lag, ie. the earth takes a while to warm up & cool off. So even though the sun is at the same height at the autumn & spring equinoxes, the climate is warmer at the autumn equinox (so may require a little more shading than at spring). Eaves alone won't be too effective to the E & W, as they'll only block the sun from the late morning to the early afternoon. Only big eaves (ie. covered alfresco) would be very effective. So along with minimising glazing, vertical awnings or shutters are recommended, particularly on the W side. For any W facing glazing where this is not possible, surface treatments (tinting) are a good idea. Good luck. Re: Passive Solar Design in Sydney 3Jun 08, 2014 1:32 pm Quote: Really depends where you are in Sydney, ie. your proximity to the coast I couldn't agree more. W & SW Sydney have summer temps up in the high '30's but also get frosts in winter. On the coast here - rarely of either. There is a very good thread on these forums called House Orientation... where a lot of things like site planning, obviously House Orientation, eaves overhang and a lot of other things concerning making the best use of your house at the planning stage as ddaroch touches on above. viewtopic.php?f=31&t=55057 In particular have a read of related matters on these two informative sites http://www.yourhome.gov.au/technical/index.html and Brian Ashworths excellent site http://www.anewhouse.com.au/?cat=62 Quote: I believe for Sydney's latitude 900mm is the optimal eave width, for due N orientation, but don't quote me on it. Close but no cigar. It is more to do with your sill height and whether it is a window or door. 400-450mm is better for eaves overhangs for standard 2400mm high walls but as you say adjustable awnings etc are the way to go. Because the OP is in Sydney when they lodge the DA they will have to have some sort of shading device etc as part of complying with a Basix Certificate or upgraded glass and frames for doors and windows. I've posted a sketch well into that thread that shows you the suns angles for mid-winter and mid-summer. Stewie Re: Passive Solar Design in Sydney 5Jul 22, 2014 3:18 pm DO make sure you've got a good plan for solar power STORAGE so that you can maximise the energy you collect during the day. Otherwise you'll still need to be hooked up to the grid for evening electricity. Looks like a big project by the looks of it too, but there are quite a number of places that you can seek help for a project like this in Sydney. Good luck! Re: Passive Solar Design in Sydney 6Feb 14, 2015 8:49 pm I think you should pay attention to passive solar heating, but rather try to integrate into your design Trombe walls, or other principles of indirect heating using natural convection air to their advantage! interesting and useful information I found on this site Code: http://mydome.in.ua/tromb-wall http://mydome.in.ua/tromb-wall , but alas it is in Russian, but it will not be difficult for online translation Re: Passive Solar Design in Sydney 8Mar 01, 2016 4:53 am Stewie D Quote: I believe for Sydney's latitude 900mm is the optimal eave width, for due N orientation, but don't quote me on it. Close but no cigar. It is more to do with your sill height and whether it is a window or door. 400-450mm is better for eaves overhangs for standard 2400mm high walls but as you say adjustable awnings etc are the way to go. Because the OP is in Sydney when they lodge the DA they will have to have some sort of shading device etc as part of complying with a Basix Certificate or upgraded glass and frames for doors and windows. I've posted a sketch well into that thread that shows you the suns angles for mid-winter and mid-summer. Stewie Thanks for the correction Stewie. Good to know Re: Passive Solar Design in Sydney 9Mar 01, 2016 10:51 am Where it becomes difficult is where you have a door such as a bifold leading out onto a balcony on the same wall as a window with a sill at standard 1000mm above floor level. Not so much of a problem where the stud height is 2400 and a usual eaves overhang of 450mm but for any higher and you start to see the door copping some heat in summer. You can vary the eaves width over the doors to stop that but that can lead to problems too unless you go for a shading mechanism. Stewie 0 4974 I looked into it a few years ago and my conclusion was to just build a carport that will support panels and get a system installed separately. The company I looked at had… 1 6481 Thank you so much for the effort. We will use it to talk with builder. We also had idea of building duplex instead and seeking suggest ions. viewtopic.php?f=31&t=106744 11 13830 |