oil vs electric ?

alanco15

hi, i live in suffolk, and am currently paying about £140 amonth for oil :mad:
we dont have gas in the village, so i was wondering if this is about right ,it does seem steep to me.

how would this compare to just using my emersion heater and getting some electric heaters or something . maybe even installing a log burner

does anyone here use soley electric for c/h ,hot water and cooking,if so how much is your quartely bill.

p.s i live in a detached four bed bungalow ok insulation, heating on about 5-6 hours per day.

any suggestion would be much appreciated, or am i just being TIGHT !!!:rotfl:

samtheman1k

It is easy to work out the cost of electric, just multiple the power output of an electric heater by the KWH price and that is your running cost per hour. So, assuming you had 3 2kw heaters on for 10 hours a day, that is going to cost you 6x8p per hour = 48p/hour = £4.8 for 10 hours use (about £150 per month I suppose), although this will of course depend on the number of hours of use. You then need to add your immersion heater (3kw?) and cooking/lighting etc.


I have just installed an air source heat pump that runs on pure electricity and have running costs of around £1.5-3 per day for my entire electricity consumption as it is 200-400% efficient. However, installation costs are high, so only worth if you are there for long enough for the investment to pay off.

Cardew

samtheman1k wrote: »

It is easy to work out the cost of electric, just multiple the power output of an electric heater by the KWH price and that is your running cost per hour. So, assuming you had 3 2kw heaters on for 10 hours a day, that is going to cost you 6x8p per hour = 48p/hour = £4.8 for 10 hours use (about £150 per month I suppose), although this will of course depend on the number of hours of use. You then need to add your immersion heater (3kw?) and cooking/lighting etc.


.

Unfortunately it is not as easy to work out the cost of electrical appliance as the above post would indicate.

Nearly all the appliances that consume power have a thermostat or variable power.

So the example given above would only apply if they never cut out on the thermostat; and in practice they obviously would be switching on and off.

That also applies to immersion heater, cooker, fridge, freezer, iron, microwave etc etc.

I have just installed an air source heat pump that runs on pure electricity and have running costs of around £1.5-3 per day for my entire electricity consumption as it is 200-400% efficient. However, installation costs are high, so only worth if you are there for long enough for the investment to pay off.

I am conversant with both ASHPs & GSHPs and am well aware of their advantages; although depending on the outside temperature the efficiency can be well below 200%.

Reading the quote above is IMO totally misleading. A heat pump provides heat -and your post is written as if it provides your electricity at 200% - 400% efficiency.

As a matter of interest how do you heat your domestic hot water? via a heat exchanger and if so how hot does the water get?

It would be interesting if you could post details of your system and installation costs.

samtheman1k

Yes, you are right, my explanation was a bit simplistic for the runnin gcost of electric!

As for my system, I went for the Mitsubishi Ecodan heat pump boiler as it has a standard 22mm water based flow and return so you can connect it directly to the central heating system & it also means it can be installed by a standard plumber rather than a specialist. I combined it with a Gledhill thermal store for hot water. Details are here:

http://www.mitsubishi-aircon.co.uk/

I was going to write a full description in a new post when I get round to it as I know there are others on here with the no gas don't want NSH problem, but haven't got much time at the mo, but will get round to it! I only installed it last month, so haven't had a 'good' run of it yet, but seems to be around £3 per day if it is on for most of the day (for all electric, including cooking, hot water etc), although the weather has been quite changable recently!).

Cardew

It would be really interesting(when you get the time) to have a report on your system - size of system, installation & running costs etc.

A specific query is what temperature of water does it achieve? I have read that both Air and Ground source heat pumps cannot get the water hot enough for 'normal' radiators, which is why underfloor heating is seen as a solution - or oversize/extra radiators.

samtheman1k

The temperature from the heat pump comes out at about 50-60deg C during normal use (according to the Boilermate sensors). The Boilermate HP actually has a 3kW inline electric heater to give the water a boost in temperature if required, but I don't think it is using this at the moment, and only will when the temperature drops outside. The boilermate has an external thermoneter to adjust the temperature of the water, but I have found that produces water that is too cold, so I have removed this to ensure that the water temperature stays at the maximum and then regulate the house temperature via a thermostat and TRVs. The following shows the output temperature of the heat pump verses outside temperature:



So you can see that you'd only really need to use the electric boost if the outside temperatures drop below about -10/-15degC, which is rare for where I live in the South East, if you base your radiator sizes on a water temperature of 50-60degC. In fact, looking at that graph, I think I'm losing too much heat through the pipe between the boilermate and the heat pump, but I haven't finished insulating them yet (make sure you have good stuff (~£5/2m), not the normal stuff and keep the outside pipework as short as possible). ryansairconditioning.com (iirc) is where I got my stuff from.

In terms of radiator sizes, Gledhill recommend that you oversize the radiators by 20%. However, we were a bit cautious in this and actually when for a 50% increase in our living room by swapping a single skin for a double skin one, and went for a 100% increase in the main bedroom as we like to be toasty! We did this by have two single skin radiators (due to the layout of the room). Our kitchen has a plinth heater that is rated at 100% extra IIRC, but it is a fan assisted one so is the same size as a lower rated one. We are installing underfloor heating in the bathroom too with a heated towel rail.

I've created a post in this forum providing more info.