Which system to go for ... AGRRRGGGHHH

Taff10

Hello all, thanks in advance for bearing with me.

We are in the early stages of buying an old stone farmhouse
(circa 1800) and at this time it is heated by the dreaded oil fired central heating with radiators. There is no mains gas in the village.

I was getting all excited about getting underfloor heating in matched to a ground source heat pump however having had a long chat with the people at NU-HEAT, they concluded that as a property of this age will not have the necessary level of insulation to meet part 'L' of the current building regs then the heat pump would be inefficient and so not reccomended.

The oil boiler at the min is an old Aga type thing ( a copy .. dont have the name at the min ) and looks on its last legs and so needs replacing.

Im now scratching my head and a bit over whelmed by then many many products on the market.

I was told by NU-HEAT that they could couple the oil fired boiler to the underfloor system. Has anyone had experiance with this and if so what are the running costs like when compaired to the radiator run system.

At the minute there is some double glazing which we would hope to run right trhough and as we will be lifting the floors to relay them insulation will be added at this time so hopefully this will make a difference. I think that it would cost a small money pit to insulate all the walls to the part 'L' requirement.

Does anyone have any suggestions as to possible alternatives or point me in the right direction.

Thanks again

Cardew

Most underfloor heating(UFH) runs at very low temperatures - 30C to 40C is typical. So I would be surprised if Oil CH would be a good choice.

I think you are wise to have reservations about a GSHP in such a house. Also the installation costs of a GSHP with the larger radiators/UFH required, tend to be huge £15k to £20k. You would do well to read the Energy Saving Trust 12 month field trial on heat pumps(both Air and Ground)

The option you haven't mentioned is an Air to Air heat pump. This tends to be much cheaper. I had a purpose built system in a property abroad with ducting to all rooms. However many people don't like warm air heating.

As you have an oil tank and suitable radiators and hot water tank??, a new oil boiler(not AGA) and installation should cost under £3,000?

The advantage of oil is that it is a tried and trusted technology; the downside is the volatile oil price.

An aspect that many people ignore is the capital cost of heating installations. If Oil CH costs say £3k, an Air to water ASHP say £10k and a GSHP £15k. Thus, having oil, you can invest the £7k or £12k saving in a long term saving account @ 4.6%(the best 'safe' account). That produces an annual income(compounded) before tax of £322 or £552. That goes along way toward oil running costs.

Having gone through exactly this exercise with my son who has bought a large house - albeit well insulated - he has gone for a new oil CH system.

P.S.
The long awaited RHI might make heat pumps a better proposition, and it would help if firms learnt how to install them properly in UK!!

Taff10

Many thanks for that. Ive made a pile of phone calls this afternoon and i think that we will have to stay with oil but upgrade to a new energy efficent oil fired boiler which will no doubt be more efficient that an old range.

Having spoken to the sales dude he informed me that pairing this to underfloor would be a great match as the boiler wont have to work so hard and will 'stay in condensing mode' (?) which is good right ?

Having done a pile of research the range of boilers by GRANT seem to be the best bet.

Any experiances with this brand as ive not heard of them before.

Thanks again
Ian

albyota

Grant make very good boilers, so do Worcester Bosch, Vaillant, plus others, and yes UFH will keep it in condensing mode. Id still go with ASHP with UFH though.
Calorific Value of oil is 10.5kWh per litre, (60p/L) about 6p/kWh
Electric is on avg 12p/kWh, you would need an ASHP with a seasonal COP of at least 2 to equal cost per kW of oil, most heat pumps would exceed this....a seasonal average COP of 2.8 would give you 12/2.8 = 4.3p/kWh..........at COP 3 its even better, still worth considering? if you cannot insulate to part L, then you are going to be wasting expensive (oil) fuel, as opposed to a, not so expensive (electric @ 4p or 5p per kWh) fuel. Check out Panasonic Aquarea TCap or the HT kit.

Gloomendoom

How thick are the walls? Our house is 300 odd years old and the walls vary from over four feet thick at the bottom to two and a bit at the top. We have no double glazing or insulation (apart from the attic which has 10-12".) The house is cosy and, considering its size and rambling layout, not particularly expensive to heat.

My point... don't get obsessed with Part L.

[Deleted User]

If you are planning on major renovations why plan around one of the most expensive forms of heating with highly volatile prices?

My thoughts are it does not matter what heating system you have you must still insulate whether it is 1860s or 1960s.

That's what we did... EcoDan ASHP in 100 odd year old house with ufh/fancoils. See some of my old posts for more details...

House maintained at 20c all year round with a WBS [free wood] in the lounge for cosy evenings.

We pay about £650ish a year for total leccy (we do have solar PV to which helps keep the bills low). Much cheaper to run than our last modern Wimpey semi with mains GCH.

Suggest shopping around as many installers as you can and ask to visit reference sites. Also do as much research as you can on renewables till you understand them, how they work and the best type of heat emmiters for your house/lifestyle. A poorly installed/designed GSHP/ASHP will cost you dear....

lovesgshp

You have not said how many sq mtrs the house is, which could determine the GSHP sizing. Many renovated houses here are over 200 years old, without super levels of insulation, but still they go for heat pumps. Ours is 1759, just roof insulation as no loft and double glazing, always warm though.
Get the thermal load requirements with the double glazing calculated in, before you decide and then work out the options.

jandyt

Hi, first time on here, although I have followed some of the forums.

I'm also racked with indecision about what sort of central heating system to go for after my 15 year old oil fired system finally gave up the ghost last week.

I have a fairly large detached property (4 upstairs bedrooms), 2 decent sized downstairs reception rooms plus kitchen, additional shower room and toilet along with 2 basement rooms. I had been interested in investing in an Air Source system, but concerned given the relative novelty of these systems and different experiences of using them (on one of the other threads).

We do have a 3.5kw Solar PV system which was installed just before the December 2011 deadline- hence the interest in the ASHP as I thought this may contribute a large percentage of running the ASHP.

That said, whilst the ongoing saga of rising oil prices, is a bane of my life, the thought of paying £3k-ish to install a new oil system is a lot more attractive than about £10k for ASHP.

The current (broken) oil boiler is a Trianco Eurostar 125. Looking at the data plate inside, the output figures given are 36.6kw and 125,000 BTU. This has always given enough heat for the house as well as providing us with plenty of how water.

The house is pretty well insulated, despite having been originally built in the late 1920s, but added to massively around 1980, I have had cavity wall insulation put in last year as well as 300mm loft insulation.

I'd really be grateful for any advice on what would be the best option to consider. Thanks in advance!

Cardew

jandyt wrote: »

I'd really be grateful for any advice on what would be the best option to consider. Thanks in advance!

Welcome to the forum.

I hope you have read this thread:

https://forums.moneysavingexpert.com/discussion/2968958

The opening post sums up my view.

The two major factors that tend to be ignored are firstly the huge capital cost of heat pumps(which you point out) which adds hundred of pounds in lost interest(or interest paid on a loan) to the effective running costs.

Secondly even with a decent COP, the comparison is not 'like-for -like', as explained here:

It is also pertinent to point out(as I have before!!) that when considering the COP of ASHPs firms never take into account that the heat produced when occupants are out of the property, or in bed, is wasted. For instance it might be
necessary to keep the ASHP running 24/7 because of the inability of the system with low temperature water to quickly bring the house up to temperature. It might be that, say, 30kWh will be produced when occupants are out or in bed.

With gas/oil CH with water at 80+C there is no need to heat the
house when occupants are out/in bed, as 20-30 minutes will bring a house up to heat. Yet in the inevitable comparisons of running costs, the 'unwanted' 30kWh is always used to swing the comparison in favour of heat pumps – and still fails!

In a thread with the Energy Saving Trust contributing, they agreed with the above.

albyota

Hi, for a start off, do as much research as you can on all the (45 manufacturers) heat pumps, Daikin Altherma HT, Panasonic Aquarea TCap or HT if you have radiators, and oil boilers for that matter, if you going to be living there for more than five years.....Go for the heat pump......if less, wack in a oil boiler, running costs for a heat pump are typically 30 to 40% of what you would spend on oil for the same heat.

e.g. 24,000kWh of heating with oil...roughly 2,400 litres @ 60p/L is £1,440.........heat pump @ COP 2.8 is 7,142kWh @ electric 12/kWh is £857

albyota

Cardew......have you ever researched the Daikin Altherma HT.......80 degrees or Panasonic Aquarea HT 65 degrees, have you ever stood next to one.....felt the temperature of the radiators......looked at the power consumption when its working at minus 7.........and worked out much less it costs to run than an oil boiler doing the same?
I don't think I'd call 80 degrees......low temperature....then again even at 45 or 50 degrees you wouldn't keep your hand on it for long.....try it.