What is the method of most efficient and cost effective method of water heating?
Energy efficency
(7 posts) (6 voices)-
There is no single answer to your question. It depends on the circumstances you are in and how you define efficient and cost effective.
Most efficient in terms of minimal energy consumption would be solar with inline gas boost but this is one of the least cost effective from an upfront capital cost perspective.
Most cost effective from a capital cost would be off peak electric storage but this is probably the worst in terms of efficiency.
Perhaps if you describe a little more about what it is you are looking to learn a better answer to your question could be prepared.
Posted Wednesday 19 Sep 2012 @ 7:34:06 am from IP # -
Greg C
MemberIf you have good solar access, an electric boosted solar hot water system is probably best. With current evacuated tube collectors you can probably get 95% of your hot water for free.
Why electric boost? Cheaper and the only energy source you can buy free of GHG. I have a normal Aquamax tank 315l. They have hot water outlets on both sides fed by an internal plastic tube that goes right to the top. It is a simple matter to burn through this pipe on one side so you can put the return from the collectors in there. I have the top element connected to continuous tariff so it just tops off the top 50 litres or so to 60C when needed. Also you can turn the booster off knowing it will heat the water up again very quickly. Over the last few days I have experimented with only turning the booster on when it is off peak rates and it is fine if there is some sun during the day. I have ancient flat plate collectors.
Like Munter I agree it depends a lot on your situation. Do you have an existing Off Peak tank that you could convert to solar. If you live in a unit, your options will be limited, or if you live in a house that is shaded maybe a heat pump system could be best even though I don't like them much due to noise and complexity.
Posted Wednesday 19 Sep 2012 @ 12:21:32 pm from IP # -
alfresco24
MemberAtul, Taking your question straight up - a solar heater into a large insulated tank which uses a solar powered circulating pump. The tank is mounted high so as to allow gravity fed hot water to your taps. Use plastic piping wherever possible to minimise heat losses. Add an in-line electric hot water heater(s) for boost when needed.
If you want a more conventional mains pressure solution then follow Munter/Greg's comments.Posted Thursday 20 Sep 2012 @ 9:36:37 am from IP #
