Will steam generated inside an oven not break it?

[mfb]

Quick clarification: for insulation and fire safety i would hope a typical oven is an airtight, steel chamber -- except for the softly-closing, hinged door.

With such a design heating the oven (reducing the amount of air inside) and then letting it cool would create an under-pressure in the oven, which would either break the glass or make it impossible to open the door. Even natural variations in the air pressure would make the oven unusable on days with a higher atmospheric pressure. You need some opening that can keep the pressure inside at atmospheric pressure independent of the direction of the pressure difference.

 

[hutchphd]

I have a convection oven and it is ventilated, not as in the picture above, but through a dedicated vent near the back of the top, the black thing you can see in this picture of a similar model

The fan in a convection oven typically recirculates the air. Turbulent airflow conducts heat much more quickly than laminar flow at the surface of, say, a turkey (or anything). That is why convection ovens cook much faster.
Yes all ovens are vented (I'm sure old ones more so than new). I think making steamed buns in an oven should work but be sure there is a pan of water intercepting any radiant heat and keep the oven only marginally above boiling (maybe 250F). Preheat it with the water in place . I always use a bamboo steamer.

 

[russ_watters]

With such a design heating the oven (reducing the amount of air inside) and then letting it cool would create an under-pressure in the oven, which would either break the glass or make it impossible to open the door. Even natural variations in the air pressure would make the oven unusable on days with a higher atmospheric pressure. You need some opening that can keep the pressure inside at atmospheric pressure independent of the direction of the pressure difference.

The door. The door is not sealed. So even the rest of the oven were airtight, it could not hold positive or negative pressure. On mine, the "gasket" is a woven wire "fabric".

Also on closer inspection it has a 4"gap at the bottom.

I do wonder how much energy could be saved if an electric oven were unventilated and just used a fan for convection.

 

[Wrichik Basu]

Honestly, I am pretty sure this won't be an interesting taste to the people other than the south part of India

Are you talking about idli? If yes, I am from Kolkata and I find them tasty too.

If your electric oven is a microwave oven (I haven't read thoroughly through the whole thread), then it is not airtight. Many years back, I put in some food in our microwave for warming, and I did not remove the paper container that it came in. After some time, I found smoke rushing out of the microwave -- a part of the container had caught fire from the heating element on top of the microwave cavity.

Our microwave came with Idli plates. There is a large bowl, within which one can put water, and then put the idli plates filled with batter inside the bowl, above the water. The construction of the plates and the bowl is such that if the proper amount of water is poured in the bowl, they will not touch the idli plates. We tried it out once and the idlis were quite good, and were not burnt.