Hi Jim, Thanks for your input. You sparked a train of thought that led to some fruitful searches on the net the key was heat exchanger. The best way to set up what I want to do is utilise a thermal store type tank with 3 integral heating coils for solar (bottom of tank), wood stove & backup condensing boiler (middle of tank). This type of tank seems to be the most efficient way of incorporating all heat sources & utilising the heat for both hot water & space heating in one unit with minimal pipe work. But an added advantage is that it will provide mains pressure drinkable hot water on demand (using a heat exchanger to heat mains water with hot water from the thermal store) with fast recovery after heat depletion for both hot water & space heating.
Ive found a company in the UK that build custom tank units & I may have to pay £700 for what I want, but with the pipe work costs (including the solar collector home build) & the price of the wood stove it should pay itself off within 2 years. (Ill do the installation myself) So hopefully I can soon shake off the gas grid dependency, at least for most of the time! Keep fingers crossed. Ill keep you all posted on how things progress. Best regards to all. Malcolm _____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of JAMES PHELPS Sent: 03 December 2006 04:22 To: biofuel@sustainablelists.org Subject: Re: [Biofuel] Central heating systems using multiple heat sources Malcome Wrote, "But it's not that simple - a combi boiler system is pressurised, but a gravity fed system isn't. How can the two be combined in a seamless "hands free" manor? " You can either use a Heat exchanger system between them or you have to go to a pump/regulator/relief system to run together. I don't know of another way unless you just run the whole system at the higher pressure." if possible" If you consider the simple boiler system and how it works then add Heat source two you just have to have your fuel valves working in harmony so you dont overpressure the system. Another consideration with these systems is to have a large volume tank so you can get the heat of the solar stored for the night when it is needed. G'Luk Jim Jim ----- Original Message ----- From: malcolm maclure <mailto:[EMAIL PROTECTED]> To: biofuel@sustainablelists.org Sent: Saturday, December 02, 2006 5:26 PM Subject: Re: [Biofuel] Central heating systems using multiple heat sources Hello folks, not piped up for a while been busy - but regards to Keith, Midori and everyone, hope you are all doing well!! I have searched the archive but I think I may not be using the right keywords or too many keywords resulting in lots of wvo references etc - I've searched the net but all I get is companies selling general services & a small handful advertising what I'm after but as you'd expect they don't provide diagrams.... What I'm trying to do is set up a solar heat collector for hot water, a wood burner stove with back boiler to run space heating & hot water if there is no available solar & a condensing combi gas boiler as a backup. Sounds simple, of sorts, when you first look at it - bit of extra pipework, a couple of extra copper tanks, a few motorised valves, a controller..... But it's not that simple - a combi boiler system is pressurised, but a gravity fed system isn't. How can the two be combined in a seamless "hands free" manor? Does anyone have any good links, ideas or diagrams for such a system, or anything close. I know it is feasible because I have seen companies selling duel / triple fuel source systems. As far as the controller goes, a great friend of mine is a computer / electronics genius (he used to work for IBM) I mentioned the kind of controller I'd need & he said it would be a doddle to build it, & he'd be glad to do so. If any of you are interested in that & depending on how I manage to progress with the project we would both be more than willing to share that technology, however it is early days. I hope someone can help - my brain is in knots with it now!!! Lol Take care all Malcolm _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
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