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| Thread ID: 94671 | 2008-11-07 03:57:00 | Running radiators off a wetback. | martynz (5445) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 718372 | 2008-11-07 03:57:00 | Basic set up: Multifuel stove with wetback connected to heat exchange coil in low pressure HW cylinder. I understand that radiators can be fed by T junctions off the wetback connections. But how do you pump the hot water round the radiator circuit without it exiting via the open vented pipe? I can't find any circuits that show details......if indeed its possible. Martynz |
martynz (5445) | ||
| 718373 | 2008-11-07 04:15:00 | We don't sat the word: "wetback" in the US for it's insensitive connotations. The idea of "running" something off one is just cruel and unwarranted too. They are nice people who do our menial chores and pick our crops. Words we DO use like "Indians", are generally acceptable and we have no fear of using them. Ya wanna cause an international incident here? |
SurferJoe46 (51) | ||
| 718374 | 2008-11-07 21:02:00 | Why not use the thermo-syphon system - it is effective and cheap to install / run? Just needs a bit of thought in the layout and Bob's short for Robert. | R2x1 (4628) | ||
| 718375 | 2008-11-07 22:18:00 | Basic set up: Multifuel stove with wetback connected to heat exchange coil in low pressure HW cylinder. I understand that radiators can be fed by T junctions off the wetback connections. But how do you pump the hot water round the radiator circuit without it exiting via the open vented pipe? I can't find any circuits that show details......if indeed its possible. Martynz It is indeed possible, every DIY magazine in the UK used to have how to install your own central heating systems. I have installed 2 in the past. In NZ they are obsessed with only having registered tradesmen doing such work, that's probably why there is little or no general info around. The pump is more of a circulator, the pressure being sufficient to cope with the flow resistance of the pipes and radiators. The vent pipe will be at a height sufficient to have a head greater than the pump head. You really need to study the topic in detail, especially calculating the flow resistances so that the pump can be sized. |
Terry Porritt (14) | ||
| 718376 | 2008-11-08 01:07:00 | Here are some sites with useful info, note that in the UK a wetback is called a back boiler: www.stovesonline.co.uk www.diydata.com www.deals4homes.co.uk www.houseprofessionals.com www.diydoctor.org.uk |
Terry Porritt (14) | ||
| 718377 | 2008-11-08 04:47:00 | Why not use the thermo-syphon system - it is effective and cheap to install / run? Just needs a bit of thought in the layout and Bob's short for Robert. Unfortunately that won't work unless the radiators are significantly higher than the wetback....thats why boiler rooms used to be in the basement. Thanks for your input Terry, I've spent some time looking for those kinds of diagrams. One big difference about the UK systems is the business of venting into a header tank rather than above the roof. Pumps seem to be of 2 types: single speed therefore fixed head or variable speed therefore variable head. Martynz |
martynz (5445) | ||
| 718378 | 2008-11-08 06:14:00 | For an 'open' non-pressurised system it is quite essential to have a header tanker for the radiator circuit. It maintains a constant water content and prevents air getting into the system. It is fed from the cold water supply via a ball cock, same as the normal cold water header tank. Air will come out of the water anyway, and radiators and pump need venting occasionally. Also you dont want to waste hot water by venting to outside. The New Zealand venting system is absolutely primitive by any standards, and could never be used safely in areas where there are continuous frosts and snow. Another function the header tank performs is retaining 'additive' that is usually added to the central heating water to keep the pipes and radiators clean. Pretty well essential in a lime hard water area, and when using 'microbore' pipes for the radiators. |
Terry Porritt (14) | ||
| 718379 | 2008-11-08 19:17:00 | Unfortunately that won't work unless the radiators are significantly higher than the wetback . . . . thats why boiler rooms used to be in the basement . . . . Martynz I will retract all the warmth I thought I enjoyed over a few Rotorua winters then . What a deluded chap I was . There were no radiators . The heat came from 2", (50 mm) pipes on the wall of the lounge and main bedroom, the flow from the wetback was slightly downhill (Maybe 1/4" in 30') until the u turn, where it dropped about 6", (150 mm) and returned flowing very slightly uphill to the fireplace . T junctions at the wetback went to the hot water cylinder to the right, house heating to the left . No air venting was required, that was done by the existing hot water system . No pumps, one tap in the return pipe to give the full attention of the fireplace to the hot water cylinder in summer . I was unable to think of a cheaper or simpler system . I had full access to trade prices on circulating pumps, but considering the minimal contribution they make to heating I abstained . |
R2x1 (4628) | ||
| 718380 | 2008-11-08 21:52:00 | Fires burn at about 800 C when at their best. Water boils at 100. Ever notice how steam driven engines - ships - cars etc have all vanished. Its because the boiler is incredibly inefficient. Back boilers are the worst of the lot. In Christchurch (I think it was last year) some tests were made between an efficiently heated house and an old design. Those in the old house were dreadfully cold but when they took the advice to disconnect the back boiler found things improved immensely - as indeed they should have. Dump your back boiler. |
Thomas01 (317) | ||
| 718381 | 2008-11-08 22:08:00 | Fires burn at about 800 C when at their best. Water boils at 100. Ever notice how steam driven engines - ships - cars etc have all vanished. Its because the boiler is incredibly inefficient. Back boilers are the worst of the lot. In Christchurch (I think it was last year) some tests were made between an efficiently heated house and an old design. Those in the old house were dreadfully cold but when they took the advice to disconnect the back boiler found things improved immensely - as indeed they should have. Dump your back boiler. The wetback/backboiler martynz is talking about is a multifuel stove, this will be very much more efficient than an old open coal fire with backboiler where a damper was opened and the flames rushed up the back and then up the chimney. Most central heating systems use gas,solid fuel or oil heating a boiler, your analogy to steam driven engines is not valid....we are not intending to to go anywhere... :) :) |
Terry Porritt (14) | ||
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