Does An Empty Oven

[Tilly2]

warm up quicker than an oven with shelves?

I always take the shelves out when I warm up the oven, prior to cooking.
Is it necessary?

[chrissa1]

Yes Tilly but, when you put a cold shelf in the oven, the temperature will drop, therefore needing extra power to regain the cooking temperature.

[Tilly2]

Eccles, why do you want to know?

[humbersloop]

Tills, no, it makes bu66er all difference, what matters is how many times you open and close the oven door

[Tilly2]

Chrissa, I always wait until the temperature light goes out before I start counting the cooking time. It doesn't take long.

The shelves do not freeze as they lie on my kitchen table, They are at room temperature.

[Svejk]

not likely, tilly. x

I have to be careful what I say on here. They'll only take the p1ss.

[Tilly2]

divebuddy, who cooks shelves? I cook food!

[Tilly2]

Sweety, who will take the mickey?

[chrissa1]

Who is, sweetie?

[Graham-W]

The shelves are metal and will therefore hold more heat energy than air. The most efficient way would be to pre-heat the oven with only the shelves you intend to use. It would be a waste of energy to heat shelves you are not going to use.

[askyourgran]

It wouldn't make any difference to the warming up, opening the door to put cold shelves in would take the time to warm it up again negligable. I couldn't do with shelves hanging around the kitchen, especially if I'm baking a batch I leave mine in the oven sometimes with the grill pan.

[shoota]

Do you have shelves (ie a solid surface) or racks with bars?

[Tilly2]

I have racks with bars, shoota.

[Tilly2]

Surely, all that metal in the oven, grill pans et al, would make a huge difference to the time it takes to heat it all.

[sherrardk]

Surely the extra time to heat up all the extra metal is negligible? My rubbish cooker seems to manage ok.

[Tilly2]

Perhaps I should have put this question in the Science category.

[Graham-W]

If a steel shelf weighs 0.25kg and you are heating it from 20c to 180c you will use 0.0017 more Kilocalories of energy than heating the same volume of air.
Don't ask me to work out the cost of electricity or gas used as my head is spinning already.
It's years since I did heat calculations.

[Tilly2]

Aww, graham. Just give me a ball park figure.

[EcclesCake]

Have you given any consideration to the amount of heat you lose whilst the door is open as you are replacing the shelf in the hot oven?

[Graham-W]

Without producing even more steam from my lugholes, it's going to be less than a penny.