We have our wind turbine up and running well, and are now considering our options regarding heating.
Heating oil is now about 49p per litre, and as we use 3600 litres a year we are keen to change to something cleaner that runs at a similar cost. At present we have a Rayburn range that also heats 8 radiators, and it is not the most efficient of things.
Our options are storage radiators, an electric boiler, a ground source heat pump, or Kalirel type panel heaters.
The heat pump heating radiators is the preferred option but is expensive to install.The house construction is a mix of dry stone walls in the old part with the newer part being non cavity concrete block. Also, we have non-insulated concrete floors. Insulation throughout is plaster board backed with about a centimeter or so of polystyrene so probably needs improving. The only way of doing this seems to be removing the old stuff and insulating behind using rockwool or polystyrene type insulation, then putting in new plasterboard. This is costly even on a DIY basis.
Do any of you have a heat pump that heats radiators? If so, what is the temperature on the radiator itself? Our radiators run at a temperature of about 37 deg C when measured by leaving a thermometer on top and keeps us at a comfortable level.
Basically what I am after is someone who has changed from oil or gas and can give price comparisons on how much difference there is in running costs.
We don't get LPG here, or mains gas either, and no trees so can't use a woodburner.
Thanks for any ideas.
--
P J
Electric Heating. Which type to go for?
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Peter Henderson - 2008-01-01 16:49:21 |
| Re: Electric Heating. Which type to go for? | Simon Ridout - 2008-01-02 17:35:29 |
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While I have no direct experience of ground source heat pumps, my sister investigated thoroughly and decided not to go ahead. Their problem was that the radiators were not big enough to cope with the lower heat of the hot water, compared to a boiler. Yours seem to be running at a low temperature and may well be large enough. Idealy GSHPs work best with underfloor heating as this runs at a lower temperature than radiators. Do you have sufficient height to lose 100cm downstairs with 50mm insulation and 50mm screed containing the pipes on your floor? Other considerations are - do you have enough land to dig the trenches for the pipes or do you need the more expensive borehole? While not a diy task, external insulation has many advantages, you do not lose room size and the thermal mass of the stone / concrete serve to stabilize temperatures inside. -- Simonridout |
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| Re: Electric Heating. Which type to go for? | Colin - 2008-01-03 01:31:07 |
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Have you thought about an air source heat pump, e.g. the Daikin Altherma? It'll be a lot cheaper to install than GSHP. Rough cost £7-£10k installed (excluding fiddling with your existing heat distribution) and running costs will be less than oil. Expect seasonal (not peak) coefficient of performance of around 3. You should be able to integrate with solar thermal hot water to reduce running costs. BUT you need to carefully consider the size of your rads. An oil/gas boiler is typically running flow temps of 60 degC but to get good efficiency/ cheaper running costs out of GSHP or ASHP you'll need to be running at 35 degrees or so. If you have the original rads in the house, and have upgraded your insulation a lot they might be ok, but you'll probably have to double them to get the output. -- Quisling |
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| Re: Electric Heating. Which type to go for? | Ted Marynicz - 2008-01-03 16:35:22 |
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Your other option is for an electric flow boiler - which will be far cheaper than a GSHP installation.
http://www.dealec.co.uk/acatalog/Heatrae_Sadia_Amptec_Electric_Boilers.html Although I can't tell you what your running costs might be. ted |
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| Re: Electric Heating. Which type to go for? | pkmwgs - 2008-01-04 14:38:56 |
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Hi peter i currently have 8 square metres of solar tubes & 6kw turbine connected in series to a 500 litre combi tank. 3 kw immersion heater at the bottom, 2kw & 1kw half way up the tank. i can switch between immersions depending on the wind output. all of the above is connected to the heating system. if i put on 5kw the heating stays at approx 50 degrees with very little help from oil burner. the tank acts sort of like a battery bank. i hope this can be of some help. -- Patrick |
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| Re: Electric Heating. Which type to go for? | William Andrews - 2008-01-07 15:04:53 |
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-- wbandrews Hi I have a three bore hole GSHP rated at 8kw heat output . It feeds a radiator system with radiator surface temp. of around 45deg C. I used to have a bulk propane system heating the radiators and annual cost was around £800 per anum probably nearer £1000 at todays prices. The secret to success of radiator based GSHPs is to ensure that at the lower surface temperatures the radiators have enough area to work efficiently. Typically they need to have twice as much area as one working at 80deg C( fosil boiler temp.). The numbers are as follows . For 1 kw into your GSHP you will get somewhere beteen 3.5 to 4 Kw out. The figure of 4K is for underfloor lower temp systems. Installed cost for mine was £6000 but running vosts are now 50% of the old propane set up. Your carbon footprint is also 50% less if you acheive the 1 to $kw ratio as most fossil powered electricity power stations are less than 50% efficient. Therare a number og good UK companies making heat pumps in the UK , not imports. |
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