Rayburn efficiency?

[Helen]

Hello

6 years ago we bought a house with a oil Rayburn Royal OF7 fitted in it

- this provided all our heating,hot water and cooking. As we wanted to put in more radiators we discovered that the Rayburn didn't have sufficient capacity and we were advised to buy a new oil central heating boiler for our heating and hot water and use the Rayburn just for cooking. We now only have the cooker section lit. The Rayburn is on a cooker setting of 2 all day everyday which gives a temperature reading of 190 deg. We also use a LPG hob.

We have a 3 bedroomed detached house in an exposed area. We are using between 5000 and 6000 litres of oil a year - this seems a rather large amount and we are looking at trying to lower this. The obvious answer seems to be to get rid of the Rayburn. Before we do can anyone give me an idea how much oil the Rayburn is likely to be using? Should we be turning the Rayburn down when it's not being used? I've contacted Rayburn but haven't had a reply from them. If the Rayburn goes it is likely to be replaced by something similar - does anyone know if the newer models are more oil efficient?

Any help would be greatly appreciated Regards Helen

[owdman]

Any conventional cooker is likely to be much much cheaper to run than a Rayburn - mainly because you can switch it off when not in use. S'obvious really! Also a normal cooker is much more practical and versatile than Rayburn/Aga etc. If you really like the "Aga" style of cooking then you can mimic it easily on a normal cooker - but without having to buy special pans etc. Not sure why you'd bother however. The good news is: you can probably sell it 2nd hand and get most/all of the price of a proper cooker.

cheers

Jacob

[Peter Parry]

might give you some guidance, Aga/Rayburn and efficiency are generally mutually exclusive words. From that data the Model 208G uses 88 kW/hr of gas to provide just 2 hrs cooking and 100 gallons of hot water per day. Compared with any normal oven/hob and boiler combination that figure is abysmal. The Aga figures are at and are similarly depressing.

anyone know if the

Not really, all of this type of device lose about a kilowatt an hour through the chimney when simply doing nothing. 24kW/hr a day for cooking before you even start cooking isn't exactly efficient. The whole concept is very 1920's with efficiencies to match.

[Andy Hall]

If you go to

and navigate to the Rayburn site and technical section, there are details on patterns of use.

Some models are designed to have the cooking section turned up and down, while on others it is intended to be left on a constant setting.

The issue of total oil use is likely to be much more related to the insulation of the house. Normally, most of the heat will be released into the envelope of the house anyway if you have a conventional flue going through 2 floors.

We have a gas run Aga with a conventional flue which runs through the corner of an upstairs room and enters the loft, finally exiting on a special ridge tile. The flue is barely warm to the touch at the top of the run in the upstairs room. Usage is around 700W or so on a continuous basis.

An oil model would run somewhat warmer and more heat is lost outside, but the point is that most is released inside the house. Therefore, before rushing into changes, I would check into the overall insulation of the house. It may be that that is the amount of oil needed to heat it regardless of the contribution by the cooker.

If you were looking for a cooking-only appliance, the Aga is an excellent choice.

[Andy Hall]

Not necessarily. It depends on the pattern of use, and heat released by a Rayburn or Aga is generally additive to the main heating system, whereas with a conventional cooker/hob it is often necessary to open windows during a cooking session if the kitchen is not large.

Nonsense. These are highly practical and versatile.

No you can't.

You don't need special pans - just reasonably decent ones.

[The Natural Philosopher]

I have to agree.

We are using a similar amount of oild in a very large house, insulated to mdern standards.

The oil gauge hardly moves in sumer when the aga and HW is on, but the CH is not. I reckon I probably saved about 500 liters by not suing te aga at all in the summer months - june july and august.

It burns at about 800W average

The oil boiler runs at 12KW. # And 10KW is what the peopel who did the calcs reckon the house needs to stay warm (let alone GET warm) at -5C average outside temps...and yes..in cold snaps that boiler runs almost continuously..at something like 12 times the aga consumption.

Get insulated. Your Rayburn is simply a VERY efficient space heater. Our

800W aga provides heat for most of the normally habitable parts of the house in spring and autumn. A mere 800W!

Only in direst winter do we need to boost that with the boiler.

Insulation makes HUGE difference. I could not work out why I had cold feet last might...down in the living room, till i remembered I had left a 3 sq ft hatch open into the loft...despite going through three doors, that cold air found its way down to my feet...

[The Natural Philosopher]

An aga is a nice space heater that you can also cook on, and in.

However, it works in a sufficientlty different manner fom other cookers to mean that those who have barely learnt to boil an egg on a gas hob, will never get to use its full potential.

I p[ersonally think that the exhaust gas temperature at teh flue pipe top where it stips geating te rioom, is a LOT colder than the exhaust temp ogf my oil boiler.

As a heater, its VERY efficient.

What it isn't though is regulable - given a constant kitchen temp its oil usage tends also to be constant. Once the kitchen goes over about 23-25C we turn it off altogether, and use the electric.

[Andy Hall]

That depends on the flue arrangement. If it's a balanced flue, possibly. If it's a conventional flue, a large proportion of the is released inside the house and adds to the space heating.

Except that that isn't the complete picture of what is happening.

[Gordon Henderson]

We had an ancient coal-fired Rayburn (Before replacing it with a gas Stanley). It was designed to run on "tick-over" ie. the oven temp was "low" and it consumed a minimal amount of coal through the day. When we wanted to cook on it, we opened it up, threw some more coal on it, and half an hour later it was toasty and ready. (which gives you time to get all the food prep. done in the mean-time)

Our Stanley works in the same way - there is a temp knob on the front, it's set to cool or 1 or 2 (when it's really cold!) (equiv. to gas mark numbers in the oven), but when we want to cook, we crank it up and it's hot in about 10-15 minutes.

So I'd imagine that if your Rayburn has a similar control, then it might be designed to work in the same way. Kept at low to keep the thing & the kitchen warm (we have no other form of heating in the kitchen which is an old stone barn on the side of the house!) then you crank it up for cooking.

Agas, having more insulation work in a different manner, in that they are always hot & ready, but the cooking techniques are the same, and as Andy pointed out you don't need special pans, just good pans, and a good set of pans will last a lifetime, so it's worthwhile spending on them - just once, and looking after them, no matter what type of cooker you have.

Gordon

[owdman]

As you see many Rayburn owners turn them off in the summer and make do with an ordinary cooker instead. They only need to take a small logical step to understand that this makes the Rayburn redundant as a cooker. Not to mention that most Aga owners also have a collection of toasters, electric kettles, microwaves, baby belling hot plates etc etc to make up for the deficiencies of the Agas. Rayburns were an improvement on the open fired range which in turn was better than a fire in the middle of the living room floor, but things have really moved on over the last 80 years or so. So it takes half an hour or so to get up to heat - lighting and cooking on open fires can be faster than that! Latest models have added gas burners and electric ovens etc. They are evolving slowly and will eventually perform just as well as proper modern conventional cookers - which is what they will be!

cheers

Jacob

[Zaru Bezh Naya]

I can't advise on the heating/efficiency aspects of your query, but I suggest that you don't use a real e-mail address in the "From" header of your news client as it will be harvested for spam purposes.

You could use a munged address, by adding REMOVETHIS somewhere in it; changing the .com to .invalid, or using [e-mail] (the owner permits this use).

If your Service Provider demands a valid e-mail address be used, get one from e.g. Lycos or Hotmail, and *never* use it for mail; the spam, etc will be automatically deleted by the domain owner.

If you feel the need to have a real e-mail address, put one in your sig file in the fashion....

albert (dot) einstein (at) timemachines (dot) com

....which can't be harvested. HTH

[Grunff]

I won't repeat the good advice already given, but I will add this. We have a 3 bed det. house in an exposed location. The walls are stone, and between 18-24 inches thick. The loft is insulated with about 10" of insulation. All the windows are double glazed and pretty draught-proof. We use about 2200 litres of oil per year (just heating, cooking is electric).

[Andy Hall]

That's urban legend.

This of course misses the whole point. In the way that it (very effectively) works, the storage cooker concept has been improved on by the use of modulating burners for certain fuel types. The so-called "modern" add-ons are not necessary or beneficial since the standard appliance does cooking jobs in a far more effective and controllable way than these can anyway.

In fact they perform better, as originally designed than so called "modern" cookers which dry out the food, cook it unevenly, have a "one size fits all" control of temperature and overheat the room that they are in.

[John]

As a first step and making the assumption you have alternative cooking means try taking a tank level reading. turning off the Rayburn for a week or more then take a second reading to estimate the oil usage over that period without the Rayburn running. Then repeat with the Rayburn running and provided there isn't an extreme change in weather conditions you should have a reasonable basis to judge what your course of action should be. (Oil usage meters are available but not usually worth the cost here.) The rayburn (and Aga) uses a natural draught vapourising oil burner as opposed to a pressure jet and such vapourising burneres are NOT efficient by any stretch of the imagination. As regards the actual central heating usage this depends vastly on the efficiency of the boiler, size of and insulation/draught proofing of the house, occupation/control patterns etc. The above tests will give you a better handle on the problems. It may be that the actual usage by the Rayburn is high but affordable whereas the heating may be the culprit (I don't know your financial circumstances so I cannot give an opinion) so it could be that your house is leaking heat all over the place. Can you fill in some of the blanks for us?

NB vapourising oil burners NEED a high level of ventilation which introduces a lot of cold air into the room/house. They have a high risk of Carbon Monoxide production unlike most pressure jet type

[owdman]

Or quicker and simpler - go out and buy a proper cooker!

cheers

Jacob

[Mary Fisher]

I'm glad someone else said all that, Andy!

I wouldn't want an aga type for several reasons - but none of the ones wrongly stated above.Many people seem to think that the look is what makes an aga/rayburn/whatever. There's far more to it than that. The style of my present dual fuel cooker looks like a chunky aga (it's made by a daughter company) but it doesn't perform in the same way at all.

Mary

[Mary Fisher]

No. And if it were there might be some advantages ...

Mary

[Mary Fisher]

That's absolutely true. Good pans will outperform poor pans on any device. They're tools, the same applies to ALL tools.

Mary

[Mary Fisher]

Evidence?

Evidence?

Mary

[Mary Fisher]

Oh for goodness' sake!

Mary real address above - because I WANT to be contacted and don't want people to have to play word games.