Browse Forums Heating, Cooling & Insulation 1 Jan 21, 2010 10:03 am Building 4br place on Adelaide plains (actually just at the base of the foothills), looking for advice on heating options. House will be well insulated to recommended minimums for the area (R2.0 in walls, R4.0 in ceiling). Moderate amount of north-facing glazing, mostly tiled for maximum thermal mass use. Cooling will be evaporative. Gas is available, and if we decide that it is warranted, then we will probably install ducted gas heating, but I'd love to get some opinions as to whether it will even be necessary, or other options. Sustainability is one of our primary concerns. Any idea? Re: Suggestions for heating options for Adelaide plains? 2Jan 21, 2010 7:35 pm Spud, Sounds like you have done all the right passive things. The answer to your question is complext. It depends on your priorities and how you define sustainability. It is also influenced by you resource availability. What do you want? - Lowest heating costs? - Lowest GH emissions? - Lowest local pollution? - Lowest energy consumption? - Lowest material use? - Longest life-cycle? Low maintenance? And do you want to achieve these aims immediately or in the mid or long term? Natural gas - burns cleanly at point of use, moderate efficiency, GH emissions, mining and transport implications, finite Electricity (coal) - highly inefficient generation, GH emissions, no local pollution, mining and transport implication, finite Wood - moderately efficient at point of use, local pollution, harvesting and transport considerations, finite (can't be used by everyone) Electricity (renewables) - no GH emissions, technically infinite Solar heating - low efficiency, no GH emissions, better for large scale applications Heat pump/AC - high efficiency, GH emissions depend on electricity source Re: Suggestions for heating options for Adelaide plains? 3Jan 22, 2010 3:14 pm Clearly I want all of those things, all for an unreasonably low price. We're are looking for something that doesn't have too high an initial price as well as something that is fairly cheap to run. We don't expect to be running it that much - we currently use portable electric oil column heaters in our current rental (which has rather poor passive design), and even in the middle of winter we don't use them that much. We don't have easy access to wood, and don't want to pay for it, so not really interested in that option (as much as I like it). I understand that using gas is quite efficent energy-wise and has relative low emissions, but we use 100% renewable electricity anyway, so the electrical option is fine as well. If needs be, I'm quite happy to put in a ducted gas system, which yourhome.gov.au seems to indicate is one of the best options, but we're trying to work out if it will be necessary. As I understand, putting one in after construction isn't that big a deal, so maybe we will see how we go for a winter and decide then how much heating we really need - we can always pull out the column heaters in the interim if we need them. Re: Suggestions for heating options for Adelaide plains? 4Jan 22, 2010 4:04 pm In the current term natural (town) gas is the best pick for low cost and GH emissions. If we were using it up here in the Adelaide Hills my energy bills would be halved. The least polluting system would be RCAC combined with a Green Energy account. However, expect to pay twice as much as natural gas. Whether or not you need additional heating depends on your own comfort tolerances. I visited a energy efficient house in the Darlington (near Flinders Medical Centre) which had close to ideal passive solar design (+ insulation and double glazing). Winter indoor temps would drop to around 15 degrees at night. The owners found this acceptable and have no additional heating system. Our passive solar house in the Hills performs fairly similarly but maybe 1-2 degrees cooler. We still have a need to turn on heating on sunless days. As far as gas systems go , space heating, ducted or hydronics would have similar heating costs. Be sure the appropriate ducts are installed and that it allows zoning. Our last house tried to share the poorly insulated evap duct system and incurred significant duct heat losses (up to 20%). Re: Suggestions for heating options for Adelaide plains? 5Jan 29, 2010 8:47 pm Spud - Interested in who designed your home? re some heating options - this should help http://www.sustainability.vic.gov.au/re ... system.pdf Re: Suggestions for heating options for Adelaide plains? 6Jan 30, 2010 5:46 am We moved back to Adelaide (North East) after 8yrs in the UK and I've got to say, I've never been so cold in Winter here. Current rental (whilst we build) is a very nice two storey home that whilst it looks good is one of the most poorly designed pieces of junk I've ever lived in. I suspect insulation consists of a sheet of newspaper it gets that damn cold in Winter. Only has Evap collingv(upstairs) and a wall system in kitchen/dining only (not the lounge). We use around 3 of the electric column heaters during winter and pay thru the nose for it. However, for the new house we've gone R3 Ceilings R2 External R1.5 Internal (AGI Soundbatts) throughout We also have some nice oathways from the front door, up the passageway thru to family room and big sliding door plus same on the sude for plenty of breeze during summer. Will do heating and cooling post build and leaning towards ducted reverse cycle. Did consider Evap + ducted Gas but install costs roughly the same. Plan is to use the RC sparingly and hoping the insulation we have will support that approach (plus maybe the odd ceiling fan .. still be be decided) One more winter in this stupid McMansion LOL ! Re: Suggestions for heating options for Adelaide plains? 7Feb 01, 2010 9:23 am Yak_Chat Spud - Interested in who designed your home? re some heating options - this should help http://www.sustainability.vic.gov.au/re ... system.pdf Thanks for that. Building with Rendition, pretty much came up with the design ourselves with some help from them. Not much room for creativity on our block, its a typical subdivided long-and-skinny block, 9.14m wide. Re: Suggestions for heating options for Adelaide plains? 8Feb 01, 2010 7:14 pm Coal plants only can convert one third of the potential chemical energy into electricity. But RCAC (heat pumps) can move three times as much heat energy for the electricity to run it. Hence the effects cancel each other out. Therefore GH emission with this combo is about the same as burning gas or wood. If you use renewables for electricity then this is not an issue. Re: Suggestions for heating options for Adelaide plains? 9Feb 01, 2010 7:49 pm Depending on the design and actual solar gain, I'd prepare it for what you think "maybe is needed" live in it for a year , and do what's required if you have to next year - ie plan for heating but don'd do it this year. My thoughts. Re: Suggestions for heating options for Adelaide plains? 10Feb 01, 2010 8:08 pm I moved to Adelaide 30 years ago from the frozen tundra of the midwest of the US. I have frozen through every winter in Adelaide. In our present house we have a wall furnace in the family room and an r/c in the lounge room. We are now building a new house @ Noarlunga Downs and we will definitely be putting in ducted gas heating (zoned). I just refuse as I get older to continue to freeze and struggle to stay warm through every winter. I think the first settlers decided this was a Mediterranean climate, warmer than the UK hence we don't need central heating and use things like column heaters (environmental vandals stuff). I'm not falling for that line anymore. If you live in Adelaide my opinion is you need effective heating. Handover February 2011 Happy with our home Re: Suggestions for heating options for Adelaide plains? 11Feb 01, 2010 8:38 pm Adelaide's climate is fairly mild compared to the American Midwest. The problem is the average house here is not much more insulated than a tent. Our old house (circa 1991) on the plains was performing not much better than a 3 star home. It was cold, dim and draughty. We have a well insulated house with good orientation in the Adelaide Hills and we are using half of the heating energy despite being almost twice the area and being in a colder climate. On sunny days here, it can be 5 degrees outside and the inside will be a comfortable 21 degrees (no heating needed). The investment you put in during design and construction will continue to save you money for the life of the house. Re: Suggestions for heating options for Adelaide plains? 12Feb 01, 2010 9:37 pm Thanks for the tips. I have reasonable confidence in the design and insulation of our house that it will be fairly liveable in winter even without heating - I'll tell you in 18 months if that condifence is misplaced or not! I think we'll make sure the house is prepared for installation of central ducted gas heating, but if after a winter of no fixed heating we decide that its not too bad, we may just put in a single gas wall unit in the main living area, if necessary. Our current house is badly insulated and terribly designed, and we get through winter without huge amounts of heating, so we'll be fine for a winter in the new place without any fixed heating to see what it is like. Definitely sold on the evaporative for cooling though - was in a mates place the other day on a hot day and his new evaporative worked a treat, I love it. Re: Suggestions for heating options for Adelaide plains? 13Feb 06, 2010 8:40 pm Spud McDoug Thanks for the tips. I have reasonable confidence in the design and insulation of our house that it will be fairly liveable in winter even without heating - I'll tell you in 18 months if that condifence is misplaced or not! We too are unsure whether we'll get sufficient natural sunlight heating in winter - we have lots of north facing glass (double glazed) but Adelaide still does get a few cloudy days in a row. What we've done is have a capped gas point installed in the living area just in case it turns out we do need a bit of extra heating. Hydronic heating is rather attractive as it is very cheap to run, but I think would have fairly high capital costs. Not sure if it would be possible to just over spec a solar hot water heater and use the excess capacity for heating. Re: Suggestions for heating options for Adelaide plains? 14Feb 06, 2010 11:43 pm Hydronic heating is not significantly cheaper to run than a standard forced air system. This is a myth perpetuated by the industry. The biggest variable influencing the cost of heating is the unit cost per MJ of the energy source. Usually in increasing order this is wood, gas, electricity, LPG. The next variable is the energy conversion efficiency of the heating device. Most modern heating devices have similar efficiencies of around 70-80%. Heat pumps (reverse cycled AC) with a COP of around 3 have a '300% efficiency'. So a hydronic system with water heated by electricity is generally going to be far more expensive heated by gas. However, this won't be much different from direct heating from a normal gas heater. There are other advantages with a hydronic such avoiding moving air and dust but running cost is not one of them. Re: Suggestions for heating options for Adelaide plains? 15Feb 14, 2010 8:43 pm dymonite69 Hydronic heating is not significantly cheaper to run than a standard forced air system. This is a myth perpetuated by the industry. The biggest variable influencing the cost of heating is the unit cost per MJ of the energy source. Usually in increasing order this is wood, gas, electricity, LPG. There are other advantages with a hydronic such avoiding moving air and dust but running cost is not one of them. I was thinking of a solar hydronic system so it'd have a large capital cost but running costs should be fairly minimal (just a pump to push the water around). Many people already want solar hot water, not sure if its possible to share the heating tubes - just put more on the roof. Re: Suggestions for heating options for Adelaide plains? 16Feb 14, 2010 9:34 pm Pipe dymonite69 Hydronic heating is not significantly cheaper to run than a standard forced air system. This is a myth perpetuated by the industry. The biggest variable influencing the cost of heating is the unit cost per MJ of the energy source. Usually in increasing order this is wood, gas, electricity, LPG. There are other advantages with a hydronic such avoiding moving air and dust but running cost is not one of them. I was thinking of a solar hydronic system so it'd have a large capital cost but running costs should be fairly minimal (just a pump to push the water around). Many people already want solar hot water, not sure if its possible to share the heating tubes - just put more on the roof. Theoretically you purely run on solar but it would require a huge array. A 30 tube evacuated tube system has an energy output of about 5kWh/day during winter. That is the same as a bar radiator running for 5 hours to heat an entire house. You may need four times as much heating. 120 tubes? Expect to pay 20K. Hydronic plumbing 15K. Total system 35K to provide $700 of heating per year. If I was spending that much I might as well install a ground source heat pump. No tubes to break or fail. Re: Suggestions for heating options for Adelaide plains? 17Feb 15, 2010 5:14 pm dymonite69 Theoretically you purely run on solar but it would require a huge array. A 30 tube evacuated tube system has an energy output of about 5kWh/day during winter. That is the same as a bar radiator running for 5 hours to heat an entire house. You may need four times as much heating. 120 tubes? Expect to pay 20K. Hydronic plumbing 15K. Total system 35K to provide $700 of heating per year. Some friends in Canberra were quoted about 20K for a system, though I guess most designs would allow for gas boost during the really cold and cloudy periods rather than try to always be able rely on solar. The very sunny winters in Canberra probably change the equation a bit too and many people would spend more than $700/year on heating in Canberra. Still too expensive at 20K though Kind of wonder if it would be possible to build cheaper but less efficient tubes specifically for hydronic heating as you don't need to heat the water up as much anyway. Just need more roof space or even a bit of backyard. Re: Suggestions for heating options for Adelaide plains? 18Feb 15, 2010 6:08 pm I have argued for this previously. You need higher energy capture but output low temperature. A solar pool heater would be adequate. For the target temperature (27 deg C) you won't be expecting much heat loss. At that level it will be as efficient as an evacuated tube. However, no-one has done this to test my theory out. Ideally you would have a large underground storage tank for load balancing. On sunless days you can draw on the energy store for the radiant system. Re: Suggestions for heating options for Adelaide plains? 19Feb 20, 2010 6:55 pm We built a 4 bedroom house and my dream was underfloor hydronic heating with solar collectors, however this was simply not cost effective. In the end went for gas ducted heating, and have been very pleased with this. Vents into bathrooms and with a timer so it comes on in the mornings before we get up and then again before we get home. Heats the house in 15 min. Running costs are very low, low enough that we don't think about having it on most of winter. Re: Suggestions for heating options for Adelaide plains? 20Feb 20, 2010 7:36 pm Here is a bespoke ground source heat pump that was done on the cheap. Mt Best - Geothermal The author uses DIY low temp solar collectors to pre-heat water which enters an underground tank. Because it is buried, the water temps are stabilised. He then uses the source energy from the pre-heated water and couples that to a heat pump which then produces warm air. He claims COP of 4-6 (A standard air-source heat pump i.e RCAC can't manage past COP 3). Technically you would instead use the heat pump to circulate water through a hydronic radiant floor. I suggested that to the author but he didn't think it was a cost-effective solution. Hi there, I'm a conplete newbie to this, but I'm looking to put a floor down in my 6x9m shed. It's currently sitting on a 100mm thick concrete perimeter (dirt floor… 0 7147 Howdy all. I am looking for feedback on what people would do to maximise and make an area as flat as possible. 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