Tue, 19 Dec 2023 08:56:54 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=906#Comment_906 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=906#Comment_906 Thu, 08 Mar 2007 20:50:07 +0000 Leo I'm a way off starting on this but need to make immediate changes to an existing system and want to avoid work which will have to be undone at a future date.
Also an analysis of the relative costs (financial and environmental) of electricity vs gas as the fallback for heat and DHW for this system would be useful - if anybody can point me to one.
thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=907#Comment_907 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=907#Comment_907 Thu, 08 Mar 2007 20:55:56 +0000 nigel http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1019#Comment_1019 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1019#Comment_1019 Mon, 12 Mar 2007 23:52:17 +0000 Leo do you know of any figures that express this margin?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1020#Comment_1020 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1020#Comment_1020 Tue, 13 Mar 2007 01:12:08 +0000 tony
If you are going to keep the wet system that you have then step one would be to fit an accumulator tank. Then add heat sources to this. Solar may best be used to feed directly into the hot water store.

There is plenty about all this on the old forum.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1023#Comment_1023 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1023#Comment_1023 Tue, 13 Mar 2007 09:21:24 +0000 nigel
http://www.johnwilloughby.co.uk/" >Energy Prices

Tony is right in that a heat pump will make more efficient use of electricity. However heat pumps are very expensive to install, have an unpredictable COP, requires UFH or larger radiators to deliver heat and are poor at DHW production.
The COP often just about offsets the inefficiency of electricity production.

If gas is available then it is definitely the cheaper and greener option.

Installed costs for heat pumps are of the order of £1000 per Kw whereas you can get a 20Kw boiler for £1000.
You could then spend the vast sums you have saved by improving insulation and airtightness.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1030#Comment_1030 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1030#Comment_1030 Tue, 13 Mar 2007 12:48:25 +0000 Guest
I get the feeling that realistically for a draughty single-skinned Victorian house I'm never going to get the sort of thermal efficiency that most contributors to this forum are aiming for, without completely gutting, sending piles of stuff to landfill and starting again. Which I neither want nor can afford to do.

I've seen postings elsewhere suggesting that there's no point in looking at alternative/ renewable energy until you've achieved near perfect efficiency - but surely every kWh that comes from a renewable source is one that doesn't come from fossil fuels, and every kWh you make yourself is one you don't pay for.

I suppose my question is; given that my house currently consumes about £700 worth of gas and £400 worth of electricity a year, and still feels cold in winter (this winter's been OK, but last was no fun); Even after I've reduced this by thorough draughtproofing, more efficient boiler etc: is a heat pump really going to make a significant dent in my reliance on gas?

It strikes me that a solar system (or two?) for summer DHW/ electricity and a cleanburn woodburner (I'm in London & need to assess wood supply) for winter are possibly the best supplements for my situation.

In a few weeks time I hope to have the time to do a complete energy requirement calc for the house - I should be better placed to balance things out then. Is there any free/ cheap software that might help with this?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1031#Comment_1031 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1031#Comment_1031 Tue, 13 Mar 2007 12:49:30 +0000 Leo http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1033#Comment_1033 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1033#Comment_1033 Tue, 13 Mar 2007 13:31:04 +0000 nigel
Every building will be unique in working out which is the best route to go. Heat Pumps might be fine in a a very well insulated home but a total waste of time and money in a draughty old vicarage.

Your approach is right though to do a thorough assessment of the thermal properties of your house and see what can done cost effectively. When you have done that have a look at solar and other renewables.

You should check that a woodburner is allowed as many urban areas are smokeless zones and you are not allowed a woodburner or probably any sort of biomass.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1518#Comment_1518 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1518#Comment_1518 Mon, 26 Mar 2007 19:48:05 +0100 sune A wood stove needs to be installed on an open system really (ie header tank in the loft). If your system is pressurized then you can get around this by making an indirect heat exchange tank - ie a tank that is part of the open system that has a coiled, finned, pipe (eg 30m long) that is part of the closed system. You can view further details of my tank system here:

http://www.stovesonline.co.uk/stove-heat-accumulator-tank.html

I also found great improvements from fitting door and window curtains, draught exclusion, etc.

Hope that helps a little...

Sune Nightingale]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1731#Comment_1731 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=88&Focus=1731#Comment_1731 Fri, 30 Mar 2007 15:39:59 +0100 Solar bore