What heating system for renovated property? 30 November 2020 at 5:58PM in LPG, heating oil, solid & other fuels 4 replies 81 views

lancunian

I posted this in the Green money saving thread.
Would this be a better category?
Mods feel free to delete/move elsewhere if needed.

I am currently renovating a property in the Scottish Highlands to live in as our permanent home.
It is a detached single stone built 2 bedroom cottage.  It will be double glazed and have loft insulation.  It will also have a bath and separate shower cubicle.  There is no mains gas, (not for over 40 miles).  I am looking for ideas for heating and hot water.
I personally think that heating oil is only going to get more expensive, and I doubt grants are available for oil boilers anymore.  We are looking to live in the cottage for many, many years so should be able to get a return on any system installed.
I am told that there may be interest free loans available for certain boilers, ASHP/GSHP etc.
There will be 8/9 radiators in the cottage and it has a concrete floor.
We would like to look at solar panels in the near future so would an electric combi boiler, despite high KWh prices be an idea?
Any suggestions welcome.

tacpot12

I would think an electric combi boiler could be a good option for you. Although ASHP's should be more cost effective to run, they are still very expensive to buy, so the breakeven point may be many years away (possibly longer than the life of the unit?). You could have an electric combi boiler for 20 years and then replace it with an ASHP once their price has dropped.

if there is no insulation under the concrete floor, you will benefit from installing all your flooring on top of a substantial amount of insulation. You will also need to maximise the insulation on your walls and in the roof - electric heating is expensive at the best of times. You need the best double-glazing you can get, triple glazing would be better, but do your research. e.g. see here Is bigger always better - triple better than double? | BRE Group

Adding solar and battery storage when fund allow will decrease the running costs regardless of the form of heating. 

matelodave

NO-NO-NO an electric combi is the most expensive way to heat hot water heating known to man - it operates on peak rate electricity and is even more expensive to run than magic dust heaters from Fischer or Virgin Oil heaters from Rointe.

Oil is the cheapest, there's LPG or I'd consider an Air Source Heat Pump although you'd really need to up your insulation levels by quite a bit and it would need to be very carefully specified, configured and operated

lancunian

Thanks for the replies, I personally think heating oil will increase in price over the next 25 years, can't see it staying reasonably low in the long term.
I don't think grants are available for oil boilers anymore, don't know about LPG.
If I used an electric combi boiler for 7 hours a day for heating, for 5 months (same timings we had when we had an oil combi boiler) how much would that cost to run?
Hot water flow and temperature are quite important, we are looking at a separate shower cubicle as well as a bath, what system would support a direct feed shower?
There is quite a distance from where the boiler will be situated (the kitchen)
and the furthest away radiator in the living room (the cottage is quite long, about 40 feet between kitchen and living room if I remember correctly) so quite a bit of pipework.
Solar could be an option in the future also.
We hope that this house will be our last.

matelodave

I'm not really sure you understand the implications of running a flow boiler, electric combi or whatever you want to call it. You do really need to go an sit in a dark room and think about this very carefully.

You need to do a lot of proper accurate heat loss calculations to see how much heat you do actually need as you might find that you cant get a flow boiler big enough to heat your place - you may even need a three phase supply so asking for random thoughts from a forum isn't going to help you greatly especially if you've become fixated on a flow boiler. If you cant do it your self get a few quotes but make sure they take everything into account.

Up in Scotland, leccy seems to be a lot more expensive than most other places, so consider a flow boiler running at 10-12kw for say seven hours = 60-70kwh at approx 15p/kwh = £9.

The same with an oil boiler at 10.3kwh per litre and oil at a silly price of say £1 a litre works out at 10p/kwh and so would only cost only £6 for a similar amount of heat.

Solar wont really do you all that much good either I'm guessing that for the five months you are anticipating heating the place there is possibly less than six hours daylight a day, it's going to be everso cold and there probably wont be a great deal of sun when it is light anyway so you wont get a lot of benefit