Oil v emersion - any advice please?

samandmillie

Hi, we have just moved into a rented 4 bed detached (2 bedrooms in use) in the open countryside. !We have oil to heat the house and water. !I have a few questions if anyone can helP please?

* we moved in last Saturday, there was 4inches oil when we moved in. We've had the heating on once for around 1/2hr and the hot water for 4 hrs per day. !How long should the oil last us?

* would it be cheaper to keep the heating off as long as possible and heat the water by using the emersion? !If so, how long would you need an emersion on for to heat water to wash up and 2 ppl have a shower?

* if we had the water on just for 1hr each evening to shower & wash up would the water still be warm the following morning? !That way we'd only need it on once per day.

* the house has an open fire in the lounge. !Will this help to heat the house during winter?

* should I buy an electric heater for the bedrooms so we don't have to use the heating overnight in winter?

Any advice greatly received. !The tank holds around 1200 litres and take kerosene. !Many thanks

Cardew

samandmillie wrote: »

Hi, we have just moved into a rented 4 bed detached (2 bedrooms in use) in the open countryside. !We have oil to heat the house and water. !I have a few questions if anyone can helP please?

* we moved in last Saturday, there was 4inches oil when we moved in. We've had the heating on once for around 1/2hr and the hot water for 4 hrs per day. !How long should the oil last us?

Not possible to give an answer as it depends on the size and shape of the oil tank, and your consumption as well as the weather

* would it be cheaper to keep the heating off as long as possible and heat the water by using the emersion? !If so, how long would you need an emersion on for to heat water to wash up and 2 ppl have a shower?

If you have a normal electricity tariff(i.e. not Economy 7) then oil will be cheaper than an immersion heater.

* if we had the water on just for 1hr each evening to shower & wash up would the water still be warm the following morning? !That way we'd only need it on once per day.

Water in a well lagged hot water tank stays hot for a long time. Depending when the heating goes off, and when you shower(and for how long) will determine if it is warm next morning - you just need to experiment.

* the house has an open fire in the lounge. !Will this help to heat the house during winter?

Yes

* should I buy an electric heater for the bedrooms so we don't have to use the heating overnight in winter?

No

Any advice greatly received. !The tank holds around 1200 litres and take kerosene. !Many thanks

Most people don't have heating on overnight.

macman

Electric heating is much more expensive than oil per kWh.

TiredGeek

The open fire will also warm the chimney and the room above will benefit from a little extra warmth that way.

Electric is about the most expensive way to keep warm, short of burning fiver's

Ectophile

I find this http://www.nottenergy.com/energy_cost_comparison/ a useful site for comparing the cost of different fuels. Edit: Beware of the "pence per unit" column, because the units aren't the same.

Open fires are very nice, but horribly inefficient. So unless you can get firewood free or really cheap, you could be sending a lot of money up the chimney.

tlh858

samandmillie wrote: »

there was 4inches oil when we moved in. We've had the heating on once for around 1/2hr and the hot water for 4 hrs per day. !How long should the oil last us?

As previously stated, impossible to know - BUT 4 inches in a 1200l tank is very little, so you need to be looking to buy oil now, before prices are cranked sky high for the winter.

Pincher

Keep the system running all year round, otherwise the pump and valves can stick.

If you use 50p of hot water a day, and £10 of oil a day for heating in winter, you are paying 50p in summer, and £10.50 in winter per day.

Alternative theory:

You only pay £10 in winter, and get the hot water as a FREE by-product of turning the central heating on. If you manage to prove this, do come back and tell us. A Nobel prize awaits.

The immersion element is for backup, and only heats the top of the hot water cylinder; unless you have a cylinder with an immersion element lower down, meant for cheap overnight electricity.

Read something a couple of weeks ago. Country living is more expensive now, because:

1. You have to drive to get anywhere.

2. Oil instead of mains gas.

Cost of energy is driving some people back into towns.

I wonder, instead of a cup of sugar, will neighbours be coming round with a Jerry can and begging for oil in the future. Have a shotgun handy.

dgsebs

A common problem for those of us who live in the countryside. I faced the same question a few years ago and found it impossible to work out from first principles - too many estimated variables. Eventually during the summer months we connected the immersion heater with a KWh meter and measured the usage over a period of 2 weeks, found we used 12KWh per day for our hot water. Then switched over to oil for hot water ( no immersion ) for 2 months, needed the longer time to get accurate measurement of oil usage. I was then able to calculate the costs of both methods and obviously the break-even point depends on the relative cost of each fuel. With electricity @ 10p/KWh and oil at 37p/L oil was marginally cheaper however now that oil is north of 50p/L the immersion is definately cheaper for us. The reason that oil is more expensive than one would expect is due to the cumulative heat losses within the system, each time the boiler fires up to provide hot water you have to heat the main combustion chamber and all the pipework and this heat is subsequently lost to the environment. We have a condensing boiler which operates at 95% efficiency but the boiler is at the opposite end of the house to the hot water tank and hence long pipe runs ( they still lose heat even when they are insulated ) Comparing the cost per unit energy of both fuels would lead you to believe that oil would be cheaper, the only way to find out in a particular case is to do the experiment. PS due to the large increase in the oil price and the fact the boiler will soon need replacing, I am looking at combining an Air source heat pump and a wood burning stove.

A._Badger

Pincher wrote: »

Read something a couple of weeks ago. Country living is more expensive now, because:

1. You have to drive to get anywhere.

2. Oil instead of mains gas.

Cost of energy is driving some people back into towns.

I wonder, instead of a cup of sugar, will neighbours be coming round with a Jerry can and begging for oil in the future. Have a shotgun handy.

You're right. Country living is a lot more expensive - as I know to my cost! There is another downside to immersion heaters than just he running cost. The current generation seem to be made out of tin foil. They don't last like they used to.

ilikecookies

I've been experimenting with using the immersion on E7 for the hot water over the summer instead of using oil/the boiler.

On paper I reckoned it would cost me 67.2p per day to produce the water I needed using the immersion vs. 82.5p per day using oil.

The calculation I used was as follows (sharing this as I'm keen for someone to correct me if I've made an error somewhere along the line):

1) Immersion - on 4 hours a day in total to produce enough water. My immersion uses 3 kw per hour and my electricity costs 5.6p per kw/h, this equates to 67.2p (ie. 12 kw/h x 5.6p)

2) Oil - only on 1 hr a day to produce an equivalent volume of water but *I think* this uses about 1.5 litres of oil a day at 55p per litre, which equates to 82.5p.

In reality I'm finding that I'm not using as much electricity as I anticipated and in fact only like 8 kw/h in total (not sure why!) which equates to more like 44.8p per day.

So it looks like the immersion is 50% cheaper. The only caveats are:

1) 4 hours a day on the immersion just produces enough hot water for 2 baths or 2 showers which go cold at the end (which is no biggie). Whilst 1 hour a day on the boiler produces enough for 2 baths/showers without going cold at the end.

2) I'm not 100% sure oil uses around 1.5 litres per day. This was calculated based over a month. However using a dip stick to measure oil consumption is not that accurate plus changes in the outside temperature could affect readings etc.

Cardew

ilikecookies wrote: »

The calculation I used was as follows (sharing this as I'm keen for someone to correct me if I've made an error somewhere along the line):

These are comments rather than 'corrections'.

1. You are making comparisons using your Economy 7(E7) tariff. I suspect the majority of people with oil CH will not be on E7. If you want true comparisons you need to factor in the higher price you pay for the 17 hours daytime electricity.

2. As you are heating water on cheap rate through the night, you presumably won't be using hot water in that period. In which case you will not use 12kWh to heat a domestic HW tank - even if there were no warm water left in the tank - as the thermostat would operate and switch off power.

3. Without accurate measuring equipment for both electricity and oil consumption you will not be able to make meaningful comparisons.

4. A litre of oil contains the equiv of approx 10.2kWh. Using your price of 55p/litre that is 5.5p/kWh. However you then have to factor in the boiler efficiency. That can vary from, say, 60% for an old boiler to 90% with a modern condensing boiler. That would price oil from 6p/kWh to 9p/kWh. So Economy 7 cheap rate would always be a better bet. Indeed even with an old gas boiler(with pilot light) E7 might be cheaper - which is why some people shut down their gas boiler for the summer months.