Heating Systems without Mains Gas

Ajb1989

Hi,


We are in the process of buying a house (1940s Semi) in a rural village which has no mains gas supply. The previous occupant was a single elderly lady who got by with three storage heaters and an immersion heater. We are a young couple and seeing this as a future family home and therefore want to install a futureproof system that's not going to cost a fortune to run. However, we may sell if work requires us to move in a few years so do want to be conscious of not spending too much upfront if we won't see it back.


We know we definitely want a log burner which has a heater element which we will use to provide space heating and hot water during the winter. This has led us down the thermal store route with the wood burner providing hot water to a store which feeds the central heating and then a heat exchange coil for mains cold water to be heated for our hot water use.


The question is what do we do for the rest of the year when we don't want to light a log fire to get hot water. We have considered:


Air source heat pumps - but think the capital outlay is too great and the results seem mixed. Plus the lower heat supplied would still need topping up by immersion heaters to provide the hot water we need.


Solar Thermal - as we are using a thermal store I understand that the system wouldn't qualify for RHI which makes the savings seem less viable. Plus its not going to heat the water that hot either so immersion kicking in again.


Oil boiler - we have space for an oil tank on the plot but I would be put off by the visual impact and would think a future buyer might too. How much would a system for installing a tank and boiler cost? We are planning an extension so trying to find somewhere to put the boiler which then wouldn't get moved after/during the extension is also a challenge.


Solar PV and Diverter to Immersion Heaters in the thermal store - can still claim the feed-in-tarrifs for solar and get paid for 50% export where may not be exporting any if all going to heating water. Also means the power gets used to heat the water even if we are out during the day. With the wood burner taking care of winter, this seems quite nice for picking up the spring, summer and early autumn months. Would have to rely on immersion for cloudy days though.


All of the above will require wet central heating putting in at more cost, but think that would be the only way to make most use out of the wood stove, otherwise we'd just end up with lots of hot water in the winter and a big bill for immersion heating for hot water in the summer (we both like long showers).


Which technology would be best to invest in? Or are we best just updating to new modern electric heaters and getting a better storage tank and insulation for the hot water. Need to find the happy medium between initial outlay and ongoing running costs. Any advice gratefully received.

lovesgshp

You should seriously consider a ASHP, as it will provide all your hot water and heating needs throughout the year and you could still use the woodburner without heat stores etc. As I understand you get a RHI payment in the UK, so you would be recovering the expense over time. I do not know if the RHI continues if you move, so maybe some other forum member can advise.
We have found here in Italy that ASHP is now very popular and with some of the new models the COP is very good and nearly as high as a GSHP system.

nickcc

Haven't a clue what the abbreviations above mean but we've had both oil and LPG. Oil worked out cheaper than LPG but if we'd had a large storage tank rather than the usual static caravan storage bottles it would have been a similar price.

matelodave

ASHP = Air Source Heat Pump
GSHP = Ground source Heat Pump
RHI = Reneweable Heat incentive

If you are getting a new heating system then an ASHP matched to it (or the other way round) can work out very economical BUT you do need s asystem that is matched to the ASHP.

Log burners can be very cheap to run if the wood is free, but nowhere as cheap as you might think if it isn't. You need space to store it, cut it and condition it so dont believe that it's a cheap way of heating your home.

Getting one to run the central heating system as well can reduce the efficiency of the radiated heat, so you'll need to put effort in to keep it going, especially if you are out all day.

You do need to put in a lot of research to decide what is best for you,your lifestyle, your budget, the building itself and your own long term needs.

I'd doubt that the rest of us on the forum would be able to adequately advise you as all these aspects will affect your choice.

We had your dilemma and chose an ASHP but I put a lot of effort into understanding all the pros & cons of all available systems. It's fully integrated into the heating system and as we are at home all day it satisfies our needs perfectly

You don't need boiling hot water, we keep ours at 45 degrees (with an uplift at weekends to sterilise the tank). We've plenty of hot water for a couple of showers each a day. We get RHI and the system is just about paid for itself after seven years. We get £700 a year in RHI for seven years = £4900 which will pay for the unit and we've still got the benfit of cheaper heating at around 4p/kwh

Charlies

Blank(ish) canvas...great fun We can't get gas either and bought the house with an oil tank and combi boiler and put a wood burner in but only for the comfort of it - there's no back boiler. When oil was 'cheap' a few years ago we were laughing but now it's creeping up plus the boiler is on it's last legs...so we're seriously considering ASHP. We have solar electricity too which would help with running the ASHP but to be honest, I'm doing my calcs assuming we don't have it since the demand/supply is out of phase with each other. In your situation, you shouldn't see the investment as wasted, I'm sure it will increase the sale value of your house compared to a storage heater system. Do you need a new boiler? If so then that cost is offset across all options + the RHI means it could be less time than you think to pay it off.

@Matelodave...how do you get 4p/kwh? Is that working backwards from the COP i.e. it's 3.5 times efficient and your electricity is 14p/kwh? Also, do you run the ASHP overnight? We're on econ7 but worried about the noise at night (would be below a bedroom window).

matelodave

We pay around 12p/kwh (it's just gone up a bit from our previous 10.5p/kwh) and I reckon we get a COP of around 3 although it's very difficult to be precise. Our flow temperature rarely goes above 35C as it's weather compensated 0 outside = 40C flow, 10 outside = 30c flow and as I said we don't heat the hot water above 45C (we tried it at 40 but it wasn't quite hot enough)

We are on a single rate tariff for leccy and the heating is on virtually continuously although we set back the room temperatures by 2-3 degrees overnight so the consumption drops overnight, frequently to zero. That means we wouldn't get any benefit from an E7 tariff except for heating the water tank which uses between 2-3 kwh a day.

I did investigate solar, but as you say it does not synchronise with our energy consumption profile - 70% in the winter when there's not much sun and 30% in the spring/summer when there is.

We offset the cost of the ASHP against the cost of a new oil/LPG boiler and associated tank installation so it's not quite as expensive as it first appears but we did go for an overlay underfloor heating system (which we probably would have anyway) which allows us to run the system at lower temperatures than a conventional radiator system.

However the low flow temperatures mean that the place takes a long time to warm up (36-48 hours from stone cold), that's why it's on virtually continuously.

Just plumbing an ASHP into an existing radiator system is unlikely to be satisfactory as the rads wont dissipate enough heat and you'll have to increase the flow temperatures to try an compensate. Most ASHP are spec'd at 35C flow and increasing the temperatures much above that will increase the energy consumption considerably (it's reckoned by about 2.5% per degree but I don't know)

I don't think that our unit (Daikin Altherma) is noisy although you can obviously hear the two big fans running, especially when the wind is blowing in the wrong direction through the blades - but we have to be oustide and near it to hear it.

We have the advantage of having a bungalow and the unit is outside the utility room and next to the dining room window - we can't hear it in the garden, nor in the dining room but it might be audible at 3am when it's really quiet outside.

Ours is inverter driven so starts up slowly and shuts down gently not like some with reciprocating compressors that kick in and out like a fridge or air conditioner. It's certainly no more noisy than passing traffic and would probably blend in with normal ambient sound levels, depending where you live.

I did a write up on my system if you are interested - just PM me if you are interested

DREKLY

Quote.. " , otherwise we'd just end up with lots of hot water in the winter and a big bill for immersion heating for hot water in the summer (we both like long showers)..... " unquote

Isn't this the wrong way round??
surely, "lots of hot water IN THE SUMMER"
and a big bill for immersion in the WINTER

I have solar pv, in an all electric bungalow, and yes, output
even now is massive on a sunny day, but don't presume you
get nothing on a cloudy day; I have it supply my immersion
for about an hour during peak sun times, and my tank gets
up to plus 55 C usually, but yes, if it's a grim day, I may have
to override by turning the immersion on manually via a timer
at night....
The nice thing too is that you can boil lots of hot drinks during
daytimes, run appliances, and even heat up colder rooms
rather than just feeding it all back to the grid - you still get your
FITs whether you use it or not !!
I am sure Martyn 1981 will be along soon to offer sound advice,
and of course, your semi roof direction needs to be roughly
south-facing for best results too.
I shall be interested to see which way you go with this, cheers
for now, an interesting thread

macman

In terms of capital outlay, your best option by far will be an immersion heater and NSH's running on E7. That's probably the cheapest to run too, unless your wood comes free.

mfmaybe

Whilst it might not be what you are after, you can put LPG in an underground tank. Although you have to pay for the boiler, and dig the hole for the tank, you don't have to actually pay for the tank as it remains the property of the supplier. It's a lot cleaner than oil, can't be stolen, and it's quite simple (and quiet!). I can't really comment on the return on investment - by the time you factor in RHI and increase in value of the home, who can say?! But didn't want you to overlook the option.

firefox1956

One of the many problems of buying a house in rural village.
I have lived in a rural village for 35 years & would move into a town tomorrow !!
No mains gas, slow or very slow internet access, no mobile phone signal, no buses etc etc etc.........

J_B

firefox1956 wrote: »

One of the many problems of buying a house in rural village.
I have lived in a rural village for 35 years & would move into a town tomorrow !!
No mains gas, slow or very slow internet access, no mobile phone signal, no buses etc etc etc.........

In our rural hamlet, all 5 houses have mains gas!!!