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seb197

Calor Gas Vs Ashp Vs Oil Central Heating

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Hello HPC,

Hoping we may have a few people on the forum who have experience of all of these types of heating.

I have bought a 1960's bungalow that currently has a tired old oil heating system with only partial centrl heating in the house. Effectively, it needs a total overhaul.

The bungalow is not on mains gas.

I see I have three viable options:

calor gas - can then have a combi and get a tank put in the back garden. Gives all the pros of mains gas but is msot likely the most expensive. That worries me quite a lot as everywhere i go people say "Calor gas? that's expensive..." been told even having a big tank the price is the same as mall bottles?

oil - I could just replace with a new oil system. But again this could well be quite expensive in the long run etc. Plus the oil tanks do get targeted for theft.

air source heat pump - Should be cheaper than the above two if set up right. Ideally you need to use under floor heating systems. Would still need a water tank and would no doubt have to top it up with elec heating for the water temp. Problem with this system is more expensive than the others to buy and get installed. When it gets really cold can be a problem Like under -10 C.

I rally don't know which way to go with it all. I quite like the idea of the heat pump especially if I could put some solar panels on the roof to supplement the electric use. Plus there are numerous government grants. But it would still cost me more I think, but in the long run cheaper.

I am planning on sorting out some cavity wall insulation and more in the loft. Plus I am building an extension for a bigger lounge so this will be further insulated with a log burner in there too. The floors are all solid concrete so this is better for under floor heating too I believe?

Basically, I have been on the web but I just cannot find out or work out what will be best for me. I have got the calor man coming on the 23rd for a quote and talk through the options plus i am going to arrange a local renewable energy person for a quote on the heat pump etc.

HPC help me with some wisdom.

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We burn oil and I'd wager there's more bang in a litre if the black stuff than £3s worth of wood from the garage. Only one home on our street use calor gas out of thirty properties, 29 people can't all be wrong and the one remaining person is always complaining about the near £2-3k a year gas bills.

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Why don't you go with a system from a back boiler on the wood burner? I think A J Wells does one.

Fine if you are in a remote location but wood fired stoves with back boilers are very smokey as the circulating water cools the combustion chamber thus resulting in more smoke. If other houses nearby expect complaints!

To the OP. You could consider a wood burning stove. For hot water an oversized solar water heating system with economy 7 back up for winter time. Perhaps also install a small ASHP as back up.

Before doing all of this go insulation, insulation, insulation.

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Fine if you are in a remote location but wood fired stoves with back boilers are very smokey as the circulating water cools the combustion chamber thus resulting in more smoke. If other houses nearby expect complaints!

To the OP. You could consider a wood burning stove. For hot water an oversized solar water heating system with economy 7 back up for winter time. Perhaps also install a small ASHP as back up.

Before doing all of this go insulation, insulation, insulation.

One of these should deliver about 3200kwh of hot water per year. You would also want a decent size hot water cyclinder - at least 150 litres and a heat dump - ie small radiator.

http://www.ebay.co.uk/itm/SOLAR-WATER-HEATING-30-TUBE-COLLECTOR-PANEL-SOLAR-THERMAL-/221152664964?pt=UK_Gadgets&hash=item337db9dd84

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OP, your situation matches mine - 60s bungalow. I heat by oil, because that was what was installed when we moved in. I also added a mulitfuel stove and a reserve of anthracite for it, because without electricity the central heating fails, regardless of the cost of the fuel. We are not that rural, but once we were top of the league nationally for power cuts. I know of people who have had calor heating installed, they never say anything bad about it, on the other hand, they never say anything good either.

We needed to change our boiler some years ago, but stayed with oil. It is expensive, but you curtail the cost by having good insulation. Is your existing tank in good order? That will save you quite a bit of cost if its OK.

I also installed a solar hot water array, similar to the one linked to by Kurt. It preheats our hot water, but the effectiveness is reduced by the overnight heat loss from the hot water tanks. You need VERY well insulated tanks if you want to maximise the use of the array.

i also have a small PV array (850 Watts) charging batteries - in the summer it can provide all our electricity in the daytimes via an inverter (not grid-tied). More importantly, it keeps the solar hot water alive in power cuts, and also the central heating if we need it.

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Pros and cons of the 3 possible solutions that you mention below.

Air Source Heat Pump

Pros:

  • When correctly installed a heat pump will offer the lowest unit cost heating solution
  • No need for annual maintenance

Cons:

  • When installed and specified incorrectly you can end up with very high heating bills. Heat pumps can only raise the system water flow temperature by 30ºC or so before becoming inefficient unlike a boiler. If the heat pump cannot provide enough heat then an immersion heater will kick in and you will end up with high bills. See this example regarding Nibe Heat Pumps.
  • Expensive to install about £10K typicallly. You will need to improve the insulation in the property. You will need to install underfloor heating or larger radiators. This is because of the lower flow temperatures
  • They need to be run longer at lower temperatures than a boiler.
  • If you switch the heat pump off the house will take a long time to warm up.
  • Maintenance is expensive as it requires refrigeration expertise.
  • They need a reliable electricity supply.
  • They are not very good at heating up hot water. Take long time/expensive.
  • Pumps supplied by the non-major brands are unreliable.
  • They are expensive to run in cold weather. This is due to energy being required to defrost the coil unit.

LPG Boiler

Pros:

  • Cheapest installation cost. £1.5K if simple
  • LPG supplier may do deal to install the boiler and tank. (however, you'll pay with a higher tank rental or unit cost.)
  • Most reliable if you pick a good brand. Worcester or Vaillant.
  • Takes up smallest amount of space in house
  • Works well in cold weather.
  • No need to improve insulation or radiators. (Although it is a good idea to do this if you've the budget)
  • Low cost maintenance

Cons:

  • Highest unit fuel cost
  • Need to pay for tank through rental or fuel price
  • Long contracts with LPG suppliers

Oil Boiler

Pros:

  • Low installation cost (£2K if straight replacement)
  • Can shop around for fuel
  • Lowest fuel cost per KwH. (a heat pump needs to be well installed and specified to beat this.)
  • Works well in cold weather.
  • No need to improve insulation or radiators. (Although it is a good idea to do this if you've the budget)
  • Last forever.
  • Reliable if choose Worcester
  • Easy to maintain

Cons:

  • May need to replace oil tank if not up to current regs
  • Needs an annual service
  • Fuel price can shut through the roof when we get a cold spot
  • Risk of fuel getting nicked.

Given the above my conclusion would be to stick with oil boiler

Edited by Silent Dancer

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There was an interesting thread about ASHP's on MSE. Basically some chap had bought a tiny newbuild with an ASHP and was paying £100s a month to run it.

Stoves - Only economical if you have your own wood source. They cost £1000s to install and solid fuel is a colossal faff.

LPG - Massively expensive. At the mercy of cartels.

Oil - Will get nicked by pikeys.

Have you considered bog standard electric convection heaters? Yes, they're expensive to run but you'll save a fortune on engineers and plumbers when things go wrong and you'll never end up sitting in the cold for days on end waiting for the stuffing "emergency" response engineers to bother to fix the problem, as I am doing now.

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A Kurt say, insulation, insulation, insulation. The more insulation. You don't pay to heat the house, you pay to heat outside the house.

As to gas and oil, having lived a fair part of my life in England with gas boilers, and a fair part in Ireland with oil boilers I can say that I have seen very few gas boilers give much trouble and haven't seen any totally trouble free oil boilers. In either case the fuel supplier has you by the short and curleys. If you can, solar water heating seems to make a lot of sense.

As someone, may have been Kurt again, suggested on another thread, combine solar water heating with a heat store and a heat pump. Would seem to make a lot of sense.

To me, an air source heat pump seems to be a pretty complex and expensive way of reversing the losses in turning oil or gas into electricity to use for heating as opposed to using the oil or gas to generate the heat directly. You need to look at the COP and the price per BTU (or whatever unit you choose to work in) of electricity Vs the price per BTU of oil or gas allowing for the boiler (in)efficiency.

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