Kitchen thermodynamics

Two questions for the science coHOrt:

  1. In terms of heating up the kitchen, is it better to use the oven on lower heat for longer, or higher heat for a shorter amount of time - or does it matter? I am talking about baking things for which either method works.

  2. My 35 yr old, no icemaker or other frills, frost-free fridge died a few months ago. Hot air always blew out the grill below the door. There was a drip pan behind the grill, which the manual said to empty regularly. It was always dry so after the first few months I stopped checking it. Now and again I removed the grill to vacuum out the accumulated pet hair.
    I bought a new Whirlpool fridge of the same size, also no frills. It’s working great. It has no grill. The door and interior storage go almost to the floor. There’s no directions to clean the motor area. There doesn’t seem to be a discharge of hot air at all, anywhere. How come?

Well, I suppose it also depends what you are trying to avoid/gain.
If you dislike the kitchen heat, some people like to endure the higher temperature for a shorter amount of time, and be done with it. Others prefer the opposite. However, if you are just talking about maximum temperature evaluation, then it is better to use lower heat for longer duration – this is because heat is also constantly escaping from your home too.

Not sure. I assume the hot surface is at the back of your refrigerator and it is just there slowly dispensing. Usually you need to leave a inch or so to make sure the heat does not build up. You are asking why it doesn’t has a fan blowing hot air, right?

Trying to keep the room heat to a minimum in summer. When done baking, I put a pot of water into the oven to absorb the heat, and use the resulting hot water for cleanup.

And yes, though the refrigerator motor hums, the unit doesn’t seem to expel heat. That’s a plus in summer, negative in winter.

We had to buy a new oven recently. It is so well insulated, that it does not heat up the kitchen when we bake at high temperatures, such as for bread or pizza. Your new oven may be similarly well insulated??

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It’s my fridge that’s new. My stove turns 40 in October! It’s down to two functioning burners plus the oven. When the latter is on, hot air and steam emerge from a vent above the control panel at the top rear.

That’s right – it sort of doesn’t matter because energy is conserved, because energy cannot be destroyed. Heat = energy; temperature is a measure of heat. If the oven emits the same amount of energy regardless of how heat is generated over time, that energy has to go somewhere; and depending on what surrounds the oven/kitchen, it is leaving or staying in some way as temperature readings (and your perceptions) would show.

No science background but I’ll share my experience. My kitchen gets very hot in the summer and the thermostat for the ac is just outside the kitchen entrance. If I use the oven hot then the ac compensates for a shorter period of time. If I use the oven on low for long periods (tried an oven “jam” at one point) then the ac is running more frequently for the entire period. The oven is newish and not cheap, so fairly decent insulation. But just a degree or 2 increase in the kitchen temp makes a difference in my ac bill. My money is on higher heat/ less overall time. In the summer I tend to use the instapot and SV more since they don’t heat up the kitchen much.


Sorry, didn’t read it right. If I were you, I would keep the stove as long as possible. The new stuff isn’ t built as well.

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I prefer hotter and faster, get it over with then turn the fans up and blow the heat out.

As for the fridge, I don’t know, there’s work being done and heat being created and moved, it’s gotta go somewhere. Maybe fridges have gotten way more efficient?

No clue about the fridge, but as far as the oven and kitchen heat are concerned, much has to do with ventilation. (That’s assuming you’re kitchen isn’t also air-conditioned. I’ve never had more than minimal AC that I use only when the weather is beastly, so I have basically no experience with AC versus ovens/stoves.)

The First Law of Thermodynamics and the “total heat x time” generated by the oven notwithstanding, how hot the kitchen feels to you depends on how quickly the heat being pumped into the room is being dissipated. Even a well-insulated oven has to have venting to one degree or another (gas ovens needing more of it than electric), and a hotter oven will obviously pump more heat into the kitchen faster than a lower heat setting. So if you have “some but not extremely good” cross-ventilation, the lower heat setting might be much more tolerable than high heat just because dissipating a smaller amount of heat quickly will result in a lower overall increase in the room temperature.

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