what central heating

jonnym2

Hello

We are going round in circles in regards to what central heating system to use.

We have just bought a grade 2 listed house built approx 1635, its an average size three bed. It currently has no central heating system. Its not very well insulated and apart from loft insulation (wool or other breathable kind) we will be installing its not going to get much better. The walls are limestone 2 feet thick and it has single glazed leaded windows. We are bringing the house upto modern living conditions currently all within the remit of the conservation team.

We are hoping to join the barn into the main living area of the house which would increase the size by around 2/3, but this may not happen for 5-7 years.

There is a large garden, but we have ruled out the option of a ground source pump as we have been advised its not a suitable option and the cost was terrifying.

We are going to request digging the ground floor out and putting in underfloor heating but may not get permission, so it will be back to radiators.

Our initial thoughts were to get a 36kw wood burning stove with a back boiler put in the lounge, which would burn something in the region of 8-11 tons of logs per year, we would also need a boiler to heat the water in the summer months, however there are three problems with this:
-We have no direct access to the garden where the logs would need to be kept.
-We would not be able to get Renewable Heat Incentive (RHI)
-The cost of two heating systems

We then looked in to biomass boilers, both wood gasification and woodpellet. Wood gasification would have the same problem as the wood stove, getting the logs into the garden. Where as the woodpellets could be blown into the back which is feasible, sighting the boiler and its flue is a bigger issue due to the listing of the property. We have been quoted between £12000-£18000 pounds for the woodpellet setup, which seems very steep, we are on a budget, and that would be pushing it, even with the RHI repayments.

A heating engineer has strongly recommended an LPG boiler using tall orange propane bottles(seems an expensive option) as the way to go as there is no need for planning for the tanks etc, but pointed out we would need another boiler if we extended in to the extension, which seems crazy. He also recommended forgetting the thermal store or hot water tank and using for instant hotwater direct from the boiler, which I can understand in this setup.

We will be getting a log burning stove for the living room for the cold nights, but don't think its viable to use as the primary source of heat.

I'm loathed to pay £300-500 for a review of our house by a company as I have heard all they do after that is push their own products.

I'm not keen on getting oil or LPG as the price is going go up and up, but the setup cost of all other systems seems to be huge, and may not prove to be that much cheaper as there seems to be some doubt about the cost of wood pellets.

Any thoughts advise? Anything I'm missing, such as grants or finance deals?

Thanks

Jon

Robwiz

I would be tempted to live in the house as is for 12 months before making any permanent (expensive) decisions. It also depends on how you use your home – e.g. whether it is occupied during the day or not.

For example, you may find that sufficient heat from the living room escapes to the upstairs rooms so that they don't need radiators. I'd also suggest you experiment with electric heaters (doesn't matter which type) with timer switches and a thermometer so that you get an idea of how much heat you need per room for your desired (or affordable) comfort level.

I write from experience – our central heating has a leak on the ground floor which has been [STRIKE]hard[/STRIKE] impossible to trace, so our plumber has temporarily disconnected it. We only need to run the CH for one hour in the morning and we are saving £3/day net on gas by only heating with our wood burner in the evenings. My conclusion is that even with the best controls (we have TRVs and Hive) too much heat is wasted in rooms not in use and in heating up hidden lengths of pipe.

With my experience of wet central heating (four underfloor leaks in the last 15 years), I am biased against wet heating and would try really hard to avoid installing it.

Two point source options worth considering are the Cornish Masonry Stove and the Ecco wood burning stove range. They both work on the principle of thermal mass with heat being released slowly over 12 hours.

I think you're right to rule out heat pumps – they are most effective in well-insulated properties. I'm not a fan of pellet boilers – too many installations prove unreliable and they often don't live up to the 'as convenient as oil' promise.

Log gasification boilers are simpler, cheaper and more reliable than pellets but need a thermal store so they can be run in 'batch burn'. Whether you have a suitable space for a thermal store will be a major consideration. I wouldn't use logs – I would buy briquettes which come in shrink wrapped 10kg packs that are easy to carry and stack. They are guaranteed less than 10% moisture content and burn predictably.

There is an issue with RHI eligible systems – there are suppliers out there who are exploiting the opportunity and will suggest systems that are more costly than necessary. There is a parallel world of suppliers and installers who offer boilers which aren't MCS certified (but are full EU standards compliant) at more affordable prices.

Every home choice requires a compromise and with a listed building that can't be insulated, there's a choice between high heating costs or adapting to colder rooms.

macman

In the absence of mains gas, oil is by far the cheapest (or rather, least expensive) option at present. I can't imagine why you would opt for LPG over oil? It's also a tested and widely used system.

Robwiz

To check on the comparative costs of different fuels, use the Nottingham Energy Partnership website. It shows cost per kWh after taking boiler efficiency into account.

The latest numbers (Jan 14) show oil (gas oil) at 8.19p, LPG at 7.51p, kerosene at 6.93p, pellets at 6.88p and seasoned wood at 5.20p. For comparison, mains gas (online account) is 4.54p.

It's possible to get Verdo briquettes at £249 per tonne (Home Bargains) and with a boiler efficiency of 90%, the cost per kWh works out at 5.76p (4.8 kWhr/kg) and no need for a storage tank.

thenudeone

Consider an air source heat pump - the RHI payments over 7 years could pay for the installation.

Smiley_Dan

Consider an air source heat pump - the RHI payments over 7 years could pay for the installation.

... but it's important to understand the technology first. A lot of heat pump installations have been badly advised. Heat pumps tend to work at lower temps (meaning you either need large rads or underfloor heating). They normally require excellent insulation and a decent level of air tightness to work most efficiently (bear in mind they use electricity and that ain't cheap so you want it to run as efficiently as possible).

I really think the advice to wait and see is key. You don't want to rush into any decisions.

There's plenty of good advice here, but also bookmark http://www.greenbuildingforum.co.uk/forum114/ and http://www.navitron.org.uk/forum/ . I've found that when you're off the gas grid then renewables begin to become the cheapest long term option .

jonnym2

Thanks for all the replies.

Air source and ground source wont work for our house. The spec for the ground source pump was insane, 2 boreholes to the aquifer around 150 meters each and pumping 50,000 litres of water from one borehole through the compressor and returned back down the second bore hole, the electricity bills for the compressor would have been higher than for an oil fired boiler! But that's as the house is expected to be very leaky.

When we extend most of the north side will be enclosed in a new thermally rich building, but that is in quite a few years.

Unseasoned wood would be a good option as we have almost an acre of garden to season it in, but accessing is not easy and the prospect of carting 11 tons round there leaves me more than a little worried. Also wood gasification boilers are not automatic in any regard. With a young family and more on the way a wood gasification boiler probably isn't wise, my wife carrying a baby and looking after an energetic toddler while loading logs into an external boiler would result in divorce! Other wise I would go for it this option with a large thermal store.

Looks like the only options for us at the moment will be gas or oil boiler with 2 x wood burning stoves providing space heating. The cost of which is not that far away from a biomass boiler. Around £5000 pounds for the gas boiler and rads, £2000+ for the steel chimney liners and another £2500 for the the two wood burning stoves. Around £9500. The kick in the bum is I will miss out on the RHI payments.

Jonnym

lovesgshp

I have just seen your post and hope you do not mind me making a comment re the GSHP.
You say you have a large garden of approx 1 acre, so why have the company quoted you for a borehole type installation? It is the most expensive solution.

southcoastrgi

ASHP with fan convectors

jonnym2

As the house is not and wouldn't be aloud to be insulated very well and that coupled with the possibility of not having underfloor heating, the system would need to produce alot of heat to even come close to coping. The bore hole technique is better able to cope. Especially with the fan convection heaters (as mentioned above). Also as the building is listed and the whole curtailage of the garden they might insist on an archaeologist to be present through out the digging process at £500 per day.

Another heating specialist indicated that it was a commercial unit that had been spec'd, but GSHP probably wouldn't work to well unless combined with several other solutions, which setup costs were prohibitivly expensive.

There has be alot of conflicting information offered though.

Thanks jon

Posted from my phone please forgive typos

Robwiz

If you're considering wood burning stoves the concerns you have about gasification boilers apply equally – the energy density of wood is the same regardless of where you burn it.

With a gasification boiler, you would ideally have a thermal store so that you could load the boiler once a day and batch burn. Most people do this late afternoon/early evening. There's sufficient heat in the store to last 24 hours unless it's very cold, in which case you start another batch burn first thing in the morning.