For help, advice and discussion about stuff not related to aviation. Play nice: no religion, no politics and no axe grinding please.
By Colonel Panic
#1892534
After 32 years I have finally managed to get permission to remove the oil fired Aga and replace it with a "normal" cooker. One side effect of this is that the room will be "under heated" by the existing single radiator.

Question: How accurate / realistic are the online BTU calculators? Do they tend to under or over estimate the BTUs required? We tend to live in cool-warm conditions rather than NursingHome-esque heat. One calculator suggests 8,000-8,500 BTU is required, but being a drafty & poorly insulated timber framed house it can only be a guide.

Any Top Tips re type or style to go for? Being a kitchen I thought flat panel rather than tubes etc due to keeping clean. Slim Fit is very preferable due to positioning. Landscape orientation essential.
By Bill McCarthy
#1892540
I made the mistake of fitting a 2kw central heating plinth heater (with fan). It is the first heater from the boiler, is nowhere near the 2kw stated and is noisy, even in slow speed. The thermostatic switch which starts it when the circ temp is above 25deg C went duff after just a couple of months.
You could fit a double panel rad, and when you’re at it, fit a bigger one if you have the space. There are fan “assisted” radiators, but I am not acquaint with noise output.
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By Tall_Guy_In_a_PA28
FLYER Club Member  FLYER Club Member
#1892543
I have never understood quoting BTU for radiators as surely it depends on how hot the boiler thermostat is set? That said, I suppose it is as good as any measure for relative performance.

8000 sounds quite high for a kitchen unless it is also a social / dining space. The benefit of a higher BTU combined with a decent TRV is that the room will heat quicker.

We re-configured our kitchen a few years ago and all the wall space was taken up by a dresser, appliances and cupboards so we ditched the radiator and went for electric underfloor heating under tiles. Unless it is particularly cold (a handful of days per year in Sussex) the floor is on a timer from 6.30 to 7.30 am to take the chill off and that is all. The kitchen is South facing, not drafty (apart from cat-flap and obviously if the extractor fan is on) and we keep the door into the house open so residual heat from CH and wood burner finds its way in. It seems to work fine.
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By Colonel Panic
#1892545
Tall_Guy_In_a_PA28 wrote:8000 sounds quite high for a kitchen unless it is also a social / dining space. The benefit of a higher BTU combined with a decent TRV is that the room will heat quicker.

Kitchen is ~25m2, with 3.5m2 windows (wooden frames, ali secondary glazing being fitted this month), solid floor (no void below), single brick solid walls complete with drafts galore, heated room above.
By riverrock
FLYER Club Member  FLYER Club Member
#1892547
The BTU ratings on radiators should be based on Delta T50. https://www.onlyradiators.co.uk/blog/he ... -explained
Although some old products (pre 2013) could use Delta T60 (higher BTU for same radiator.

Delta T rating is calculated using the flow temperature of a boiler into a radiator plus the flow out temperature. So, if you have an input of 80 degrees and an output of 60 degrees, then this means that the average radiator temperature would be 70 degrees.

'Room Temperature' is an average accepted to be 20 degrees. So, you take that away and you're left with 50 degrees, or Delta T50.


Bigger is generally better - you can turn down a bigger radiator. You can't turn up one that is too small.
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By rikur_
FLYER Club Member  FLYER Club Member
#1892551
Just had a look. Our kitchen is also ~ 25m2, albeit double glazed with a suspended timber floor and cavity walls. When we had wet heating it had a 10,000 BTU radiator. It was more than adequate.

I'm no expert on this, but I think that wet radiators work best if consistently proportionate to the need across the whole house. In our last house when we first moved in, all the radiators were a bit under rated, but in practice it meant you had to plan ahead and get the heating on early, and it was ok. When we moved into this house, we struggled as the hallway/landing were over-rated, and some of the rooms under-rated, and therefore ended up with warm rooms, cold rooms, and relying a lot on the TRVs and lots of faffing around balancing the system. That's a long-winded way of saying I'd use what you have in other rooms as a benchmark. If in doubt, go over rated, as you can always turn it down - but you don't want to have to put the whole system on 30 minutes earlier because the kitchen radiator takes ages to warm the kitchen.

Don't go OTT though, as if the radiator is too big it will store a lot of residual heat, and the room will overheat when you get cooking as even when the TRV kicks in there will be a lot of residual heat to release. (my parents recently replaced their radiators with ones big enough to support a future move to air-source heating, but for now with the existing gas boiler. The problem is even with TRVs it's hard to stabilise the temperature at the right place)

Like @Bill McCarthy we briefly had a plinth heater - don't go near them.

Nowadays we have air-to-air airsource ....... as the phrase goes, "if you can't stand the heat, get out of the kitchen" .... or just turn the airsource to cooling mode ;-).
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By PeteSpencer
FLYER Club Member  FLYER Club Member
#1892555
Is it not possible to install electric underfloor heating by lifting tiles or over-laying?

The advantage of underfloor is that if a door gets left open, the heat that escapes is rapidly replaced by the entire floor surface.

In a radiator room, the hot air volume blown out by the open door has to be slowly replaced from the radiator and takes much longer.

That's what our developer told us................... :wink:

And there's nothing like warm floor tiles early in the morning to warm yer bare feet.
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By Trent772
#1892572
Colonel Panic wrote:After 32 years I have finally managed to get permission to remove the oil fired Aga and replace it with a "normal" cooker. One side effect of this is that the room will be "under heated" by the existing single radiator.

Question: How accurate / realistic are the online BTU calculators? Do they tend to under or over estimate the BTUs required? We tend to live in cool-warm conditions rather than NursingHome-esque heat. One calculator suggests 8,000-8,500 BTU is required, but being a drafty & poorly insulated timber framed house it can only be a guide.

Any Top Tips re type or style to go for? Being a kitchen I thought flat panel rather than tubes etc due to keeping clean. Slim Fit is very preferable due to positioning. Landscape orientation essential.


Yea - convert the Aga to electric :mrgreen:

We did ours a few years ago and:-

A. Got our hot Aga back
B. Had better heat through the cooker
C. Had to install a modern efficient twin element water cylinder which wasn't an issue.
D. Changed the 'bleed radiator' in the en suite to an electric towel heater.

Well worth the effort. Think it cost about £3,000 in total.

Contact off forum if you want details.
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By Colonel Panic
#1892596
Not realistic to install under floor heating; being a 1390 house, ceiling heights are not great and I can't be ersed with major building works at my stage of ownership.

We did look at converting the existing Aga to electric, but decided not to go down that route; main reasons being lack of instantaneousness (1-3 hours heat up time was quoted IIRC), and an Aga is almost designed (if not destined) to be thermally inefficient. Long gone are the days when we needed to cook several hot meals a day.

We've gone for a mediumly posh electric / induction range cooker for not a lot more than the cost of conversion. And we can bask in the glory of getting perhaps £60 on eBay when we get shot of the Aga. No surprises that no one wants them anymore! :roll:
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By Flyin'Dutch'
FLYER Club Member  FLYER Club Member
#1892617
lobstaboy wrote:
Colonel Panic wrote:After 32 years I have finally managed to get permission to remove the oil fired Aga and replace it with a "normal" cooker.


So you don't cook then? You might come to regret this decision :)


AGAs are good for a few things such as stews, cakes etc but useless for a lot of other types of cooking/baking including stir fry and, more importantly doing a nice juicy steak.

And the wasted money.

Never again.
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By Trent772
#1892632
Flyin'Dutch' wrote:
lobstaboy wrote:
Colonel Panic wrote:After 32 years I have finally managed to get permission to remove the oil fired Aga and replace it with a "normal" cooker.


So you don't cook then? You might come to regret this decision :)


AGAs are good for a few things such as stews, cakes etc but useless for a lot of other types of cooking/baking including stir fry and, more importantly doing a nice juicy steak.

And the wasted money.

Never again.




Whaaaaaaaaat

Stir fry - yep

Steaks.... no - it does them wonderfully
By avtur3
FLYER Club Member  FLYER Club Member
#1892633
Flyin'Dutch' wrote:
lobstaboy wrote:
Colonel Panic wrote:After 32 years I have finally managed to get permission to remove the oil fired Aga and replace it with a "normal" cooker.


So you don't cook then? You might come to regret this decision :)


AGAs are good for a few things such as stews, cakes etc but useless for a lot of other types of cooking/baking including stir fry and, more importantly doing a nice juicy steak.

And the wasted money.

Never again.



We have gas powered Aga and I can't identify with the limitations described above ...
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By defcribed
#1892756
Likewise.

We are able to do all those things with our gas-powered Aga and it does them very well. You just need to learn to use it properly.

We didn't fit it - it was here when we arrived - and if it hadn't been we probably wouldn't have fitted one due to the high up-front cost. It also does an excellent job of providing background heat for the ground floor, and hot water. We turn it off in June, July and August - if we don't then the kitchen becomes intolerably hot.

@Colonel Panic for the radiator, just make an informed guesstimate based on the others in your house and how well they heat their rooms based on their size and the size of the room. An important factor which I don't think you mentioned about your kitchen, especially given the single-brick skin, is how many outside walls it has. If in doubt choose a larger rather than smaller radiator, and once installed just adjust the lockshield valve until the heat-up time and temperature are how you want them.