Iain Robinson said:

In this regulated Health and Safety  risk adverse society I cannot believe a regulation does not exist somewhere.

There'll be a regulation and/or standard if there's a significant risk. Looking at the standards Mike lists it can be seen how these relate to the significant risks of fire, food being undercooked, or burn injuries. It's quite possible that it's not considered a significant risk if the inside of the top oven heats up (as long as the outside doesn't and the temperature control of the top oven can still work correctly when it's being used).

Apologies Iain, i misread your first post. Looking at the instructions for the example oven you posted, it says "Cooling Fan. A gentle flow of air will be blown below the control panel when the grill control is used and after a short period of time when the ovens are used. Note: Whenever the appliance has been used, the cooling fan may run on or restart itself after all the controls have been turned off. This indicates that the appliance is still warm", so it sounds like the fan for the top oven might come on if only the bottom oven is used. You could check with the manufacture whether this should be the case with your oven, and you could check whether the upper oven fan does actually come on. 100 deg C does sound excessive.

Out of interest, while cooking dinner I thought I'd borrow my wife's thermal imager and check ours. With the main oven at 190C, the metalwork in the top oven is between 95C (coolest areas) and 130C (shelves and hottest areas of the sides). 

Not being great at thermodynamics I'm not sure if that equates to

Iain Robinson said:

measured at 100C of heat transfer

but just to throw into the mix.

(Lisa Miles this is indeed where we heat the plates, they've always been fine  )

Oven doors get hot.

What age of child are you thinking of?

A toddler who is just about walking will put his or her hands against a wall in order to climb up it. If that wall is an oven door, there will be trouble. The toddler cannot withdraw because the hands are providing the support, so the palms get burned. Not nice so mothers (and fathers) have to be very careful in the kitchen.

All that said, why is the heat in the upper oven a problem? I see no reason why the two ovens should be insulated from each other.

Is there a hidden agenda here?

The point is that at 100C you can burn yourself - it should not get that hot when switched off. Perhaps the issue is greater than just my new double oven.

Chris - you ask the question " why is the heat in the upper oven a problem?" - the problem is that in a proper heat efficient oven with proper thermal insulation between the ovens -  it should not be there at all.

Well the current standards for accessible parts, (see above) which I would have thought were more of an issue than the inside of something that gets hot by design, allows well above ' safe to touch' temperatures anyway - 100 degrees above ambient for a non-metallic handle and 60C above ambient for a metal panel is still going to hurt !

But It may be that the standards writers never really foresaw the modern era.

I suggest that the cooker temperature standards are based on material that is now quite dated, and originally evolved from the cooking on a range - the sort of thing my grand parents had * , which was more or less a fire in a box and an arrangement of dampers and flaps to steer the flames around one box or the other for water, or main or side oven. Obviously that gets hot - indeed as a kid I recall trying to see how hot, and being fascinated by getting the cast iron glowing dull red, before being told off for wasting firewood.

Mike.

* similar to but not quite the model below- hers had a water boiler on opposite side to the oven). The earliest version of the modern standards came in at about the same time as the sort of things that came in post war, which were of course a huge improvement in terms of controls and safety, (my parents had a 1960 gas oven rather like the second figure) but I suspect the idea that a small child would be roaming free in the kitchen and the parents not to expect him or her  to be injured or develop self preservation instincts was not contemplated.

 
Grandparents and parents era cooking compared - note the gas 'wand' at the LH side for of the Parkinson-Cowan Prince, a portable flame intended for lighting the grill and oven by transferring a flame from the pilot for the rings, and also great fun for childhood  experiments with gas - something else that would raise eyebrows today.

That is unrealistic.

Of course one could improve the insulation, but then the ovens' capacity would be much reduced. How would that suit you?

Clearly total thermal isolation is unrealistic- 'perfect'  insulation  would also suggest no oven power was needed to maintain an infinite temperature, and as cooling down is as much an essential part of cooking as warming up, there has to be heat loss and so both boxes are coupled to the outside world, and indirectly to each other !
The question we should be asking is how much temperature offset in the 'empty' oven acceptable, and that is related to how much heat transfer causes how much temperature rise, and the equilibrium between heat entering and leaving. 
Meantimes informal thermocouple tests chez MAPJ1 have indicated that our small oven above the main one reaches 80-90 C when the lower oven is used at gas mark 6 for ~ 30 mins for an instrumented meal of fish and chips. It also shows that neither compartment has reached thermal equilibrium over that timescale, the upper unused one was still getting hotter and the lower one was more or less exponentially approaching a plateau. Also there is about 20 degrees slope between the top and bottom of the oven. ~200c at the bottom, ~220C at the top. Testing was truncated after 35 minutes due to dinner being ready and there was a 5 mins or so intermission to experiments when the peas boiled over and had to be mopped up..
I think there is an element of measuring walnuts with a micrometer about this - a different very accurate but largely meaningless result each time.

I also think your oven is actually not that different in behaviour to mine, and may not be as unusual as you think.

Mike.

mapj1 said:

something else that would raise eyebrows today.

You mean raze?

Iain how did you measure the temp?

Andy borrowed a thermal imaging camera, and I have seen differences between surface temps measured with these and the temperature recorded with a thermometer. 

Also did you check with manufacturer about the fan?