Starting from scratch!

polarity · Jul 19, 2009

Hi

When I finish the bathroom project I will be looking at heating and DHW options for our 1960's ("DIY built") bungalow so would appreciate any opinions and ideas please!

Basics:

About 145m2

no mains gas (not an option)

presently original electric UFH, according to labels 415V - not tested yet, with solid floors.

presently 2 x separate DHW vented copper tanks on "off peak" immersion heaters, bathroom and kitchen - each w/tanks in "loft" - which is shallow as it has a shallow pitch "flat roof" and not all roof space is accessible!

There was absolutely no insulation at all so we have done cavity walls, are going to double glaze (steel crital windows at the mo) and insulating the roof space as and where we can get to it.

The existing UFH looks pretty scary and probably not very efficient even on "off peak" (though has UFH performance changed much ?)

Present thoughts for new system

Boiler - LPG, Oil or Wood Pellet (very green but about 10K installed vs

Dane · Jul 19, 2009

Air source heat pump

Click here

Not the cheapest, but very efficient. 100% free (apart from cost of compressor/pump)

very easy to install.

Can have another boiler in-line aswell to boost the heat (solid fuel back boiler with thermal store)

jl-heating · Jul 19, 2009

lots of options,

air sourse as dane says.

existing solid fuel add a back boiler if available as you laready mentioned, bio mass is quite large but very effiicient and can be linked with the solid fuel.

again lpg but link to the solid fuel with a large thermal store, fit an lpg system boiler, unvented hot water via the store and pipe a standard wet system to the house,

poly pipe do a lay on under floor system mdf plates with routed slots for the pipes and relay a floor on top (44 degree working temp) this will do downstairs.

upstairs standard rads as usuall.

if you dont want ufh drops in each corner for pipework and standard rads downstairs.

options are endless

polarity · Jul 19, 2009

Thanks, I had looked at GSHP last year but ROI was too long, ASHPs seems to have got a lot better over the last year or so and with a COP of 3-4 brings it down to Gas prices for running, I had forgotten about that so thanks I will investigate.

JL -from what you are saying the store is a good idea whichever way we go, it is a bungalow so no upstairs to worry about. Adding 50mm to the floor level would be a bit of a nightmare with raising the doors etc, do you have any experience/feedback about the skirting system or wall heating (ie vertical UFH)?

Is there a w/m2 rule of thumb for a well insulated bunglow (at least it will be when we have finished!) for heat output estimation?

Thanks !

Paul

Dane · Jul 19, 2009

Thanks, I had looked at GSHP last year but ROI was too long, ASHPs seems to have got a lot better over the last year or so and with a COP of 3-4 brings it down to Gas prices for running, I had forgotten about that so thanks I will investigate.Paul

both my self and John (jl heating) have been in touch with a supplier of heat pumps, who has designed a heat pump to reach just over 65 degrees C. (65 degrees is what is required to prevent legion airs disease) if you want the details i will find his business card out.

As you say, these are getting much better though and much more efficient.

Where do you get the idea from that they cost as much as gas to run? As there much cheaper to run than gas, there is an average saving of

polarity · Jul 20, 2009

Sorry meant natural gas not LPG!

Do I still need to worry about the 65 degs if it is just circulating water/inhibitor through a heatstore?

Thanks!

Paul