Help needed re air source heat pumps and renewables

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Help needed re air source heat pumps and renewables
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Desiderata

Joined: 02 Sep 2006
Posts: 25
Location: Crymych, Pembrokeshire

Posted: Sat May 24, 08 8:36 am Post subject: Help needed re air source heat pumps and renewables

Hi all

In common with others we are suffering from the escalating cost of domestic oil. We moved in to our 100 year-old detached, stone-built dormer bungalow in Feb 07; 1000 litres cost £306 inc VAT; last week it was £606. Out house is a cold property as we are 890m up on the edge of the Preselis and have poor insulation.

We work from home and in the winter we are cold when the heating is off, so much so we can’t type on our PCs, so have resorted to one of those plug in oil-filled rads. I have already draught-excluder-ed all doors and windows and fitted 250mm of rockwool in all spaces I can possible crawl into, as well as on the sloping roof spaces I can reach, however there is no insulation in the upstairs floor (will be doing when we decorate) and I can’t get into all the space between the roof and interior plasterboard to insulate without ripping out all the plasterboard.

The central heating is run by a Stanley oil-fired 65,000 btu range and supplies heating and hot water. 1000 litres of oil lasted from Jan 6th to May 19th; when we have the heating on its on from 06:30 to 08:00 and again from 17:30 to 21:00 = 5 hrs per day. We have 3 x single 1000mm rads, 5 x 600mm single rads in total.

We have a fairly inefficient wood burning stove (installed by the last owners for looks rather than efficiency) which turns the 18c living room into a 27c luxury den! The same room in the day in winter can fall as low as 10c when there in no heating and its 2 or 3 cc outside…

We are using some 18units of electricity per day in the winter; 12units in the summer = 5475 pa. We have energy efficient bulbs and nothing is on standby.

Naturally we will be insulating as much as possible when we renovate but we clearly need to replace out inefficient oil-fried boiler. Any suggestion? We have considered the following:

1. A new condensing oil boiler – not really a consideration as we feel it essential to move to renewables.

2. Air source heat pump, such as the Ecodan https://www.mitsubishi-aircon.co.uk/default.asp?url=https://www.mitsubishi-aircon.co.uk/mitsubishi_electric.asp?id=168227 from Mitsubishi and Trianco https://www.trianco.co.uk/activair.cfm models. I understand that these work best with underfloor heating as the water temperatures generated are between 30c and 55c but I need to hear from users of the latest models – any users out there in similar properties to ours? We have considered ground source hp but not appropriate for us.

3. 5kw wind turbine located 200m from our house: cost £25000 before grants (unlikely given our poor insulation?). This is too expensive for us.

4. Smaller Windsave-type turbines £+/-£1800) coupled with thermal solar panels (+/-£4000). We will be going for the thermal panels I’m pretty sure, but what about the smaller turbine – I need to measure average windspeed and investigate planning permission – we are in the National Park…

5. Internal and external wall insulation – several companies offer external and internal is largely a DIY job.

6. Photo-voltaic panels – we have south and west facing elevations, but everyone I have spoken to – even the manufacturers – say the technology is still too unrefined as yet.

7. Electric boilers such as the Trianco Aztec https://www.trianco.co.uk/aztec_gold.cfm and Heatrae Sadia Amptec https://www.heatraesadia.com/hs/heatraes.nsf type combined with the Windsave and thermal panels.

I feel pulled to the ashp coupled with extra insulation, thermal panels and if I can get permission a Windsave turbine or similar.

If anyone has any experience with ashp:
Do they work for properties such as ours?
How many unts of electricity are you using per day in winter? Per year?
What is performance like in winter? Do rads reach a ‘can’t comfortably touch’ temperature?
Are they unbearably noisy (we have a very handy external wall)? Frankly this is the least of our worries.
How do you manage to heat the water to 65c in order to combat Legionella (other than an immersion heater)?

Anyone with experience of drilling access holes from inside a property and blowing insulation material into roof cavities, saving the need to effectively remove the interior roof I’d be grateful.

Anyone experienced in external insulation such as: https://www.exteriorinsulation.co.uk/default.asp

In fact any comments at all are welcome.

Thanks

Carl

ros

Joined: 19 Jul 2005
Posts: 2469
Location: Beds

Posted: Sat May 24, 08 8:46 am Post subject:

Have you lookied in to pellett boilers as well?

https://www.eco-link.co.uk/ph_12.htm

THink they are only as good as your source of pellets, so you would need to be sure of that, but would be relatively straightforward to plumb in to your existing CH.

Have you considered the efficiency of your radiators? we have oil heating and changing the main rads for modern double ones with the fins (can't remember what they are called) seems to have decreased the amount of oil we use (caveat there is that this wnter hasn't been as cold).

No real advise though, we have a modern, well insulated house and are struggling with our oil bills too

chez

Joined: 13 Aug 2006
Posts: 35934
Location: The Hive of the Uberbee, Quantock Hills, Somerset

Posted: Sat May 24, 08 5:20 pm Post subject:
Our solar panels will heat the water to above 65 degrees in summer. Have you tried the Navitron forums? There are some experts there that we found very helpful. We don't have a heat-pump - but we've combined the oil with the solid fuel stove via a Dunsley Baker neutraliser (equaliser?) which seems to do the job and offers us a choice of fuel - coal, wood or oil.

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Sat May 24, 08 11:18 pm Post subject: Re: Help needed re air source heat pumps and renewables

Desiderata wrote:

12 in the summer

That's high. what are you using? Ours is 4 units per day average for the year.

You need to analyse your usage to see where the most effective savings can be made first.

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Sat May 24, 08 11:20 pm Post subject: Re: Help needed re air source heat pumps and renewables

Desiderata wrote:

6. Photo-voltaic panels – we have south and west facing elevations, but everyone I have spoken to – even the manufacturers – say the technology is still too unrefined as yet.

Ball cocks. The technology is highly refined, expensive yes, but reliable and 25 year longevity

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Sat May 24, 08 11:23 pm Post subject:
re-reading your post your most productive route is likely to be a rebuild of your property. If it's as energy inefficeint as you say and you plan to live in it for the next 25+ years then it's going to cost as much to put right as a rebuild will cost.

Desiderata

Joined: 02 Sep 2006
Posts: 25
Location: Crymych, Pembrokeshire

Posted: Sun May 25, 08 1:29 pm Post subject: Heat pumps

Not sure why elec consumption is so high. We do have two upright freezers (1 old and inefficient; one new and highly efficient), we both work from home, so 2 x computers on all day, plus the oil-filled portable radiator.

Mmmh, won't suggest the rebuild to my wife...

I need to do some more digging but the most likely route is eleccy boiler combined with air source heat pump, solar thermal panels, a Windsave turbine or similar and shedloads of insulation, possibly even internal wall flexible insulation. The wood-pellet boiler is not really an option because of space.

Anyone any more thoughts?

Ta

Carl

chez

Joined: 13 Aug 2006
Posts: 35934
Location: The Hive of the Uberbee, Quantock Hills, Somerset

Posted: Sun May 25, 08 3:32 pm Post subject:
Have you looked at the 'OWL' thread? We've got ours running today and have spent a couple of hours going round switching things on and off and seeing what effect that has on the stats. Also, are there grants available in your area for loft insulation? There are in Powys, and I think some of it comes from Cardiff.

woodsprite

Joined: 20 Mar 2006
Posts: 2943
Location: North Herefordshire

Posted: Sun May 25, 08 3:39 pm Post subject:
www.organicenergy.co.uk But then I would say that, my old man installs wood pellet boilers for them and you have a good supply down your way.

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Sun May 25, 08 4:16 pm Post subject:

Insulation will give the greatest benefits for outlay, you need to get consumption down first and insualtion will do that quickly but it needs to be done properly with no gaps or heat loss spots or it will alll be in vain. Next draught proof the place as much as you can. do this at the same time as insulation. If done correctly your heating energy demans should plummet. The oil filled radiator will be your main enegry consumer so replace that with a wood fired stove if you can. Don't throw technology at the problem until you at least halfed you energy consumption as it's nowhere near as cost effective as insulation. The simpler your solution the better.

It's a common and very expensive mistake to start putting in technology solutions before covering the basics.

James

Joined: 11 Jan 2006
Posts: 2866
Location: York

Posted: Mon May 26, 08 11:04 am Post subject:
have a look at Navitron. They have single room air source heat pumps for £704 installed, and a 20 tube thermal solar kit (apparently enough to heat water for a household of 3 from March to September) for £395 (DIY install). I like the look of their air source heat pump....

Desiderata

Joined: 02 Sep 2006
Posts: 25
Location: Crymych, Pembrokeshire

Posted: Mon May 26, 08 6:24 pm Post subject:

Yep, saw that site and have been through it quite a lot. I think that we'll be insulating to the gills first - need to for grants and its common sense. Need to keep the heat we have in first, as Vegplot says.

Of course, this then begs the question how do you insulate caverties that you can't reach as per my initial post (can they blow in insulation through keyhole apertures (so we don't have to rip down plasterboard). Also, anyone any experience of the flexible foam insulation such as Sempatap and / or external cladding insulation.

I am also going to get an OWL as it would be great to know just what is using what.

Any more thoughts?

Brandon

Joined: 11 Apr 2006
Posts: 114
Location: mid wales

Posted: Fri May 30, 08 9:53 pm Post subject:

well, your house could become the warm cosy nest that you desire.

It will however take some effort.

For insulating into cavities, try talking to Jasper at Pen y Coed

[img]https://www.penycoed-warmcel.com/[/img]

they are very capable, and will advise you well.

remember that insulation is not very effective without a decent level of airtightness (cue the rumblings from some quarters...)

insulate first, and then worry about heating.

Please remember that it is not possible to keep heat in, all you can do is slow the rate at which you loose it.

"we feel it essential to move to renewables. "

"most likely route is eleccy boiler combined with air source heat pump"

how do you tally these to statements?

The wee windsaves have been thouroughly debunked, and are not worth the money.

SDHW on the other hand is well worth the effort.

I would suggest coupling your SDHW with a back boiler on a wood stove, thus ensuring hot water throughout the winter.

Insulate some more.

PM me if you want to talk more.

Cheers Brandon.

Desiderata

Joined: 02 Sep 2006
Posts: 25
Location: Crymych, Pembrokeshire

Posted: Sat May 31, 08 7:07 am Post subject:

Hi Brandon,

Thanks for you comments. Seems insulation is the way to go first. Will check the site you suggest. Seems I need to know if I have a breathable roof membrane in place first from what I hear.

Quote:

"we feel it essential to move to renewables. "

"most likely route is eleccy boiler combined with air source heat pump"

how do you tally these to statements?

Perhaps I should have said "Move to renewables as much as possible". I was hoping that a small turbine with ST panels linked to an ASHP and an eleccy boiler might sufficiently reduce our elec consumption. Reserach on the net and phone over the last few days shows this is just not possible. Almost everyone says insulate first and then go from there; ashp won't give enough heat (even with a well insulated house and 30% bigger rads) to sufficiently heat this property to 21c.

We are getting two quotes (so far) for external insulation using the Wetherby and Structherm processes (anyone done it?). We'll also most likely be going for ST panels (the word is evacuated tubes seem best on a retro fit - comments please), THEN see what the heat loss is like from the property bfore deciding next step and doing a cost/benefit analysis.

Cheers

Brandon

Joined: 11 Apr 2006
Posts: 114
Location: mid wales

Posted: Wed Jun 18, 08 5:34 pm Post subject:

evacuated tubes are great for retro fitting, and have a higher efficiency than flatplate.

be sure however that you have a cylinder in which the solar coil has an adequate surface area.

NB the clearskies certificate only required a surface area of 0.58m2 on the solar coil to qualify THIS IS A SMALL AREA, AND AS SUCH IS NOT VERY EFFECTIVE. you can get coils with upto 1.6m2.

It is also no longer necessary to change out your cylinder, and no, I am not talking an imersion replacement solar coil.

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