heating advice

[amandag38]

At the moment we have a very old oil tank, and newish boiler with immersion heater, the main source of appliance is radiators, during our project we are looking to replace this and have considered most options, essentially we will have a large 24 ft lounge, 13 ft square dining room, 12 ft study, approx 38 ft open plan kitchen garden room, plus 2 bathrooms, 3 beds, 1 utility, thatched, single glazed, and hopefully good wall insulation, in the lounge and DR we are going to have 2 woodburners, kitchen an aga, and UF heating throughout downstairs, and rads upstairs. We have considered GSHP but dont have a massive amount of land, air source sound promising but are not sure how effective they are, does anyone have any experience with them, will they run underfloor heating efficently and hot water, should we invest in a back boiler on one of the fires or an aga as a back up system, or would this be better as a primary heat source, Ideally we really want to be rid of the oil tank , and get in a more efficent combi boiler as the water tank takes up loads of space. I have tried to contact some companies with regards to sales but who would I contact for advice on which would be the better system for us, would it be a heating engineer.
thanks in advance.

 

[Schoolmarm]

Very little knowledge here but, combi boilers aren't always more efficient.

GHSP can be a borehole instead of the large area type.

 

[Andrew Bodenham]

Do you have mains gas? Are you hoping to reduce / eliminate reliance on fossil fuels?

Have you considered the expense / hassle of retro-fitting UFH? Assuming you're existing floors are solid you're looking at extensive excavation, insulation, pipework, screeding, refinishing. That's a lot of work, and a lot of concrete. I'm presuming that you are not going to living in the property during this work, so maybe the mess won't matter so much. But in my opinion UFH is an awful lot of work just to avoid having a few rads on the wall. A different matter in a new-build.

Also consider that UFH needs different flow temperature to rads, so the system requires more complex control gear. Not a problem if you manage to find a skilled designer and installer, but more opportunities for things to go wrong.

Having more than one heat source on a CH system is not as easy as you might think, especially if one of them is relativey uncontrolled like a woodburner.

I'd recommend concentrating your efforts on getting a high efficiency boiler running a well-designed radiator system as your starting point. Then use your woodburners (woodburning AGA too?) for localised carbon-neutral space heating. If you have the sort of lifestyle which allows you to be at home stoking wood then you might add a backboiler to the woodburner and a separate simple radiator circuit to spread heat to the coldest rooms. If your main CH system has thermostatic rad valves then these will compensate for heat produced from other sources. So you could provide a fair proportion of your heat from woodburning, but have the automated main CH system working in the background to fill in the gaps, if you see what I mean.

If you install a dual coil fast-recovery hot water tank, so that you have the option to do some water heating by solar or woodburner. An immersion heater will give you the option of using photovoltaics too. Bear in mind that "green" energy systems can be expensive for the amount of energy harvested, and either require fairly complex control systems or frequent attention from the user to optimise results. No doubt things will improve in the future as these systems become more commonplace - we are still on the leading edge of the domestic renewable wave.

There are so many variables in the heating equation, so you really need to do your homework. I really can't recommend a supplier of advice - but afer you've read as many books as you can find, searched the net, and spoken to a dozen engineers and installers you'll be in a better position to weed out the duff advice and talk to your chosen installer with some authority. Remember that (being a bit cynical) heating installers success criteria may not match your own; they want an easy job, quickly fitted with a good return. They don't have to live with the system. You want the best possible economy, controllability, and versatility, all artfully installed. You can see how problems may arise.....

Sorry to sound so many notes of caution, but domestic heating is a minefield, especially if you want anything beyond a simple boiler & rads system. I've seen so many poorly installed systems in houses that I've worked on, and heard so many tales of woe from customers about their CH problems. Knowledge and understanding is the way forward.

 

[Nemesis]

and a lot of concrete.

UFH can be fitted in limecrete...

 

[amandag38]

thanks for your replies, at present the ground floors are either earth (lounge) or concrete, we intend to excavate the floors as they are different levels so we are taking the opportunity to lower them at the same time, both internal and externally, the idea behind UFH was I dont particularly like rads, UFH is not practical upstairs due to head height thats why weve opted for rads upstairs. In winter we would more than likely use the fires for primary heat and the UFH for background heating, and probably the other way around in summer if needed. the aga will be electic we think as we really do want to get rid of the oil tank. we do not have gas in the village. Unfortunately we may have to keep an oil tank If the GSHP/ASHP are not a viable option. i am going to do some phoning around and see what I can find out.
Schoolmam we considered the bore hole option but the cost of the specialist ground works was phenominal, we could fit in compact collectors which we could do the ground works ourselves, so again we are still trying to weigh up the pros and cons.
P>S yes we are going to be living on site during the works, me hubby and three mastiffs oh and a cat :shock:

 

[Flyfisher]

I would echo Andrew's main point - there is no easy answer!

The 'free energy' aspect of heat pumps can be seductive, i.e. 300-400% efficiency etc, but it must always be remembered that they run on electricity, which is probably the most expensive 'fuel' in the first place. Very roughly therefore, the 300-400% efficiency of a heat pump merely brings the running costs into line with cheaper fuels such as mains gas. I faced the same dilemma and concluded that paying £500 to have mains gas connected (and saving £1000 on a new oil tank into the bargain) was better than paying £15,000+ (at least) for a heat pump. That £15000 will yield about £750 per year in interest alone, which will pay for quite a bit of gas!

The other important point about heat pumps is that they generate lower temperatures than a conventional boiler-type system. This means you either need very large radiators to transfer the heat into the house or install under-floor heating (basically a very large radiator), with all the disruption and cost that it entails.

If mains gas is really not an option (might be worth a quick call to National Grid), it is possible that oil tanks can be buried (with appropriate conditions and safeguards), which is one way of 'eliminating' them.

I would recommend a few hours playing with a spreadsheet and let the numbers do the talking - the results might be surprising.

 

[MdB]

£15,000+ (at least) for a heat pump.

That is an awful lot for a heat pump. My budget is £4500 for a self install (not including underfloor pipework and controls - £2500)

 

[Essex]

We had a similar problem, part earth and part concrete floors. As we are timber frame, (and listed) we wanted to remove the concrete floor to help the frame, and like you, lower the floors to the original level so that all the sole plates were above ground level (and high enough for my tall husband). We put in a breathing limecrete floor with under floor heating on the ground floor run by a highly efficient condensing boiler (oil 'cos there is no gas) and we will put in a woodburner in the living room, we also installed a solar cylinder and have just received planning permisson and listed building consent for the solar panel.
We installed the floors and underfloor heating ourselves, with a lot of help from Uponor who provided the underfloor heating system. The only professional help we had was a good plumber to install the boiler and a good controls engineer to make sure that that side worked properly.It was hard work but well worth it. Been in two years now and running well. Our heating bills are considerably reduced. (We also insulated well with a herd of sheep, gasketed all doors and windows and ensured all gaps between lime render were filled (still plenty of ventilation however from the chimneys, which have chimney ballons in winter but still allow enough ventilation).
If you are thinking of an Aga, and you only have oil, you might like to look at the Sandyford, they do a version with a highly efficient condensing oil boiler, it only takes 20mins to come up to full temperature so we have ours on a time clock so it only comes on for breakfast and supper. It seems to work well with the underfloor heating (which was sized for when the Sandyford is not on).
Good luck

 

[MdB]

... gasketed all doors and windows and ensured all gaps between lime render were filled (still plenty of ventilation however from the chimneys, which have chimney ballons in winter but still allow enough ventilation).

I'm sure you know this but chimneys when in use need a ventilation source for air into the room. Make sure you have that or you could risk carbon monoxide problems.

 

[Essex]

Chimney ballons come with a pipe for ventilation for this reason

 

[Essex]

Whoops, misread, take chimney ballon out before lighting fire

 

[MdB]

Whoops, misread, take chimney ballon out before lighting fire

Generally a good idea :wink:

You still need ventilation into the room somehow so air can go out up the chimney. This is very important (and a requirement for building regs)

 

[Flyfisher]

£15,000+ (at least) for a heat pump.

That is an awful lot for a heat pump. My budget is £4500 for a self install (not including underfloor pipework and controls - £2500)

Fair point if you're self-installing. Does that also include all the external pipework for the heat source? Also, what's the rating (kW) you've chosen?

 

[Flyfisher]

we also installed a solar cylinder and have just received planning permisson and listed building consent for the solar panel.

Is this the type of system that uses vacuum tubes and heats the domestic hot water? Did you get LBC for roof mounting the panels?

 

[skier-hughes]

£15,000+ (at least) for a heat pump.

That is an awful lot for a heat pump. My budget is £4500 for a self install (not including underfloor pipework and controls - £2500)

Fair point if you're self-installing. Does that also include all the external pipework for the heat source? Also, what's the rating (kW) you've chosen?

I had a quote for a 9kw model, from Ice Energy for £6k delivered. We'd then need to dig trenches, lay pipework and get it around/through/over the moat and into the house. Not something I'd like to do myself.

I'm currently looking at a wood burner boiler, like this,
http://www.blakemoreandchell.co.uk/Store/Category/Category.asp?CategoryID=67
which will fit in our fuel store, flue up an existing chimney, along with an accumulator tank, being fired by waste wood we are given and logs. £9k for 30kw boiler, 700l accumulator, 160l dual coil hot water tank and fitting.

Anyone any experience of this model?

Graham

 

[AMc]

£15K for ground source isn't unlikely. I have a quote here for £22K for a 21KW GSHP system using boreholes [fitted]. That would also require 3 phase electricity to be connected to the house. GSHP have the advantage in efficiency but we don't have the land space for slinkies. The cost of boring is prohibitive, not apparently the actual drilling which will take less than a day, but cost of hiring and getting the equipment here and back.

We're probably going to go for Altherma Airsource (£8.5K parts + £3.5K fitting, commissioning and refridgerant) for a 16KW unit - we've done a heat loss survey with the installer hence the smaller pump.

The costs are mad in comparison to oil/LPG systems but we need to offset a vinery conversion so a 'green' system is required. Once it's finally in place we'll be running it off 100% renewable electricity so it should 'carbon neutral' with running costs equivalent with oil.
Our oil bill this year went up by 1/3rd and electricity about 1/10th so it could end up cheaper in the lifetime of the system ... but with fuel prices who knows?

 

[MdB]

£15,000+ (at least) for a heat pump.

That is an awful lot for a heat pump. My budget is £4500 for a self install (not including underfloor pipework and controls - £2500)

Fair point if you're self-installing. Does that also include all the external pipework for the heat source? Also, what's the rating (kW) you've chosen?

Prices from here: http://www.kensaengineering.com/html/products.php

6kW Heat Pump (including slinkies, manifold and antifreeze) - £4915
Digger Hire - £150
VAT - £886
Discount from Government - -£1200
Total - £4751

(I've been told a typical bore hole adds around £2500 to the above)

 

[Essex]

Solar panels on listed property.
We have LBC (and planning because it was external), we are using flat plate, not evacuated tube, mounted on a frame, behind the house, by the oil tank. We can locate it in the correct location and angle with minimum overshadowing. No problems with our conservation officer, she was supportive. It is surrounded by planting so cannot be seen from the garden, but high enough up to avoid any overshading

 

[AMc]

(I've been told a typical bore hole adds around £2500 to the above)

Hmmm I was told £10K-16K by Econic. The Kensa site has a quote wizard, when you say there isn't land for slinkies it says "You will need to consider drilling - which is both expensive and mostly uneconomic for domestic dwellings in the UK.". Perhaps they have more options if you call them?

The Kensa "quote wizard" takes you through a list of questions that you need to answer 'yes' to or it dumps you out. Assuming I answer 'yes' to 'does your building have wet underfloor heating', 'space for slinkies' and 'conform to current building regulations for thermal efficiency' etc.. Their price to heat 240m2 £8K + VAT and delivery or 320m2 is £8.8K + VAT and delivery, then whatever fitting costs. My place will be 260m2 with a lot of glass so I'd be looking at the bigger unit I guess.

It's another option to dig into...

 

[MdB]

(I've been told a typical bore hole adds around £2500 to the above)

Hmmm I was told £10K-16K by Econic. The Kensa site has a quote wizard, when you say there isn't land for slinkies it says "You will need to consider drilling - which is both expensive and mostly uneconomic for domestic dwellings in the UK.". Perhaps they have more options if you call them?

Don't know to be honest. Don't need a bore hole so didn't look into it much. I may well have remembered the £2500 wrong.

The Kensa "quote wizard" takes you through a list of questions that you need to answer 'yes' to or it dumps you out. Assuming I answer 'yes' to 'does your building have wet underfloor heating', 'space for slinkies' and 'conform to current building regulations for thermal efficiency' etc.. Their price to heat 240m2 £8K + VAT and delivery or 320m2 is £8.8K + VAT and delivery, then whatever fitting costs. My place will be 260m2 with a lot of glass so I'd be looking at the bigger unit I guess.

It's another option to dig into...

Kensa are quite good at telling you when a GSHP is pointless so as not to waste everyones time. You do need a well insulated property with underfloor heating. You can also knock of £1200 from the cost due to a government grant you can get.