Browse Forums Heating, Cooling & Insulation Re: Solar hot water recommendation. 2Aug 22, 2016 8:26 pm Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Solar hot water recommendation. 4Aug 23, 2016 9:18 am Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Solar hot water recommendation. 8Aug 25, 2016 11:11 pm Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Solar hot water recommendation. 10Sep 02, 2016 9:48 am Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Solar hot water recommendation. 11Sep 02, 2016 10:16 am Owner Builders in boot-shaped Yorke Peninsula : viewtopic.php?f=38&t=80264& Re: Solar hot water recommendation. 12Sep 02, 2016 10:39 am Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Solar hot water recommendation. 13Sep 02, 2016 11:01 am Owner Builders in boot-shaped Yorke Peninsula : viewtopic.php?f=38&t=80264& Re: Solar hot water recommendation. 14Sep 19, 2016 12:24 pm Building Services Engineer Renovating our 1960's modernist home in Brisbane https://forum.homeone.com.au/viewtopic.php?f=53&t=82091 Re: Solar hot water recommendation. 15Sep 19, 2016 8:49 pm 1960sModernistHome Evacuated tubes are great but are a bit over the top for a sub-tropical climate like ours in SE Qld. Good old panels are fine. Contrary to what bpratt said (sorry mate) I wouldn't recommend running the element during the day only and not at night. The tank temperature needs to be kept above 60 degrees to avoid legionella. If you have a large family, chances are several people are going to have an evening shower/bath. Therefore it is likely that your tank temperature will drop significantly at night if you don't have the secondary energy source available to keep the tank temperature up. My recommendation would be to use solar primary heat source with an electric element secondary, with the thermostat set on 60 degrees for the best energy efficiency. I'd run it on Tariff 31 or tariff 33. Never really liked the plate collectors, as if they get broken, there goes the hot water. Break tubes, and you don't lose any water.... or are there now plate collectors that don't lose water when broken ? In my situation, the hot water is plenty hot through the night for us, and by the time it starts to chill down, i.e. cold water coming in to the tank from hot water drawn off to drop the temperature, it isn't an issue for us. If the OP is using the water after the sun goes down, then electric boosting of a night is then essential for the reasons described. Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Solar hot water recommendation. 16Sep 19, 2016 9:08 pm bpratt 1960sModernistHome Evacuated tubes are great but are a bit over the top for a sub-tropical climate like ours in SE Qld. Good old panels are fine. Contrary to what bpratt said (sorry mate) I wouldn't recommend running the element during the day only and not at night. The tank temperature needs to be kept above 60 degrees to avoid legionella. If you have a large family, chances are several people are going to have an evening shower/bath. Therefore it is likely that your tank temperature will drop significantly at night if you don't have the secondary energy source available to keep the tank temperature up. My recommendation would be to use solar primary heat source with an electric element secondary, with the thermostat set on 60 degrees for the best energy efficiency. I'd run it on Tariff 31 or tariff 33. Never really liked the plate collectors, as if they get broken, there goes the hot water. Break tubes, and you don't lose any water.... or are there now plate collectors that don't lose water when broken ? In my situation, the hot water is plenty hot through the night for us, and by the time it starts to chill down, i.e. cold water coming in to the tank from hot water drawn off to drop the temperature, it isn't an issue for us. If the OP is using the water after the sun goes down, then electric boosting of a night is then essential for the reasons described. Our plate collectors went through Brisbane's very bad hail storm in Nov 2014 and were fine. Our commercial-grade Klip-lock roof was worse for wear though... The evac tubes are good, no doubt about it, but the extra expense for efficiency is not really necessary for our northern climate. As for the element, I agree for a small hot water demand it would probably be fine to run it only during the day. I actually turn our element off at the circuit breaker for 8 or 9 months of the year and we still have (literally) steaming hot water. Building Services Engineer Renovating our 1960's modernist home in Brisbane https://forum.homeone.com.au/viewtopic.php?f=53&t=82091 Re: Solar hot water recommendation. 17Sep 22, 2016 6:21 pm 1960sModernistHome The tank temperature needs to be kept above 60 degrees to avoid legionella. So how does this work for solar hot water without a booster or with a gas instantaneous booster under heavy usage where the tank temperature will drop below 60 degrees. Is the occasional raising of the tank temperature to 60 degrees enough to keep legionella at bay. How occasional does this need to be ? Every several days, once a week, ... ? Re: Solar hot water recommendation. 18Sep 22, 2016 7:46 pm Most modern systems will have automatic boost with a thermostat, so if the tank drops below the set point (say 60 degrees) the element or gas flame will operate until the temp goes back up over the set point. With an older system with manual boost only, that might be an issue. I'm not expert enough on legionella to be advising on that in any more detail. Building Services Engineer Renovating our 1960's modernist home in Brisbane https://forum.homeone.com.au/viewtopic.php?f=53&t=82091 Re: Solar hot water recommendation. 19Sep 22, 2016 9:06 pm I believe instant gas boost requires it boosted to 70+ degrees to deal with legionella in a shorter time frame, which is then cooled back down to 50 degrees via the tempering valves. Likewise, I'm no expert on legionella either ! Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Solar hot water recommendation. 20Sep 23, 2016 8:06 am bpratt I believe instant gas boost requires it boosted to 70+ degrees to deal with legionella in a shorter time frame, which is then cooled back down to 50 degrees via the tempering valves. Likewise, I'm no expert on legionella either ! Yeah you'd think that a daily "purge" (for lack of a better term) would kill off the nasties. Realistically legionella not a huge problem in domestic. But when we have reticulated warm water systems for hospitals, aged care facilities and the like, that is when it becomes a serious (and tricky) issue to manage. Trying to strike a balance between eliminating hot water scald hazards, and keeping the water hot enough to kill bacteria, can be an engineering challenge. You then end up with a building full of tempering valves that need regular testing and maintenance (which is an ongoing cost). Building Services Engineer Renovating our 1960's modernist home in Brisbane https://forum.homeone.com.au/viewtopic.php?f=53&t=82091 the sun master is the solar heating to "warm" the water in the tank the S26 is your hot water system which will heat the water (25 degrees?) so with both turned on you… 2 13673 I want to build a decking to the drawn shape outlined in black. The problem is how close can I build to the gas hot water unit? Will I be able to build around it and be… 0 20226 DIY, Home Maintenance & Repair Hi, I've got a brand new (2nd hand) Bosch Hydropower 16H tankless hot water heater. Since it was installed I have noticed it leaks a lot. I took the cover off and it looks… 0 24147 |