# Pizza delivery thermodynamics **URL:** \ **Category:** Factual Questions\ **Created:** [November 19, 2022, 11:39pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224 "2022-11-19T23:39:49Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 19, 2022, 11:39pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/1 "2022-11-19T23:39:49Z")
Which of the following would result in the warmest take home pizza ? It’s understood that there are many variables that could be involved, but for the sake of simplicity I’m only including what I feel are the major considerations. If there is an important factor not listed or if the numbers used are grossly inappropriate, feel free to point this out and change as you see fit. Otherwise let’s “KISS” initially. The background: It’s winter, 20 deg F ambient outside. Car engine is warmed up upon arrival @ the pizza place, heater is discharging 115 deg F **at the outlet** @ 80 CFM, the ambient inside the car @ the seat however is still a chilly 35 deg F and with (for the sake of argument) no air movement. The pizza was handed to me @ 325 deg F. Time to transport is 15 minutes. Ambient temp in the vehicle upon home arrival is 85 deg F. Where best to place the pizza to ensure the warmest delivery to the table @ home? 1. On the floor next to the heater discharge **OR** 2. On the seat in calm air. ---
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [November 19, 2022, 11:47pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/2 "2022-11-19T23:47:10Z")
On the floor next to the heater discharge. The further you get from the heat souce (the discharge vent) the lower the ambient temp around the box and thus an increase in the heat being drawn out of the pizza. I don’t see windchill be a factor since it is a warm breeze ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [November 19, 2022, 11:48pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/3 "2022-11-19T23:48:51Z")
A lot of the time the floor is the best way to keep the pizza flat, which is important. If I was concerned about the difference in heat between the floor and the seat, I would invest in an insulated pizza delivery bag. ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [November 19, 2022, 11:51pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/4 "2022-11-19T23:51:54Z")
If the car has been running and the floor is warm to the touch by the heat discharge I would definitely put it on the floor. However, if the floor feels cold I wouldn’t since it will suck the heat out of the bottom of the box. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 19, 2022, 11:52pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/5 "2022-11-19T23:52:15Z")
> [@Si\_Amigo](#): > > I don’t see windchill be a factor sunce it is a warm breeze “Warm” compared to what? It’s probably cooler than the temperature of the pizza. The pizza will cool down until it reaches the temperature of its surroundings, and it’ll reach that equilibrium quicker with moving air than it will with still air. ---
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [November 19, 2022, 11:53pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/6 "2022-11-19T23:53:57Z")
> [@Chronos](#): > > Warm compared to what? Warm compared to the still ambient air at seat level. My scientific observation is that your feet tend to get toasty before your bum warms up. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [November 19, 2022, 11:58pm UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/7 "2022-11-19T23:58:54Z")
> [@bobot](#): > > A lot of the time the floor is the best way to keep the pizza flat, which is important. If I was concerned about the difference in heat between the floor and the seat, I would invest in an insulated pizza delivery bag. Agree about keeping it flat; I remember a couple of pizzas when I was a kid that ended up with all of the cheese slid to one side. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 20, 2022, 12:03am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/8 "2022-11-20T00:03:33Z")
This is exactly my conundrum. Air velocity as related to BTU transport. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 20, 2022, 1:05am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/9 "2022-11-20T01:05:43Z")
I was simply trying to provide a real world scenario of my question…If I was unclear… Not looking how to keep a pizza flat, nor how to enhance delivery temp with the purchase of insulators or heaters (Domino’s pretty much has that figured out) nor how to differentiate my vehicle floor temperature from various aspects of the environment. However I am looking for some semblance of an explanation for the heat loss (or gain) of an object related to air flow and temperature differentials. Simplistic equations appreciated. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [November 20, 2022, 1:16am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/10 "2022-11-20T01:16:03Z")
> [@ZurBob](#): > > - On the floor next to the heater discharge > **OR** > - On the seat in calm air. 1. In the pizza over you installed behind the driver’s seat: [https://youtu.be/F-TTCKF2iTQ](https://youtu.be/F-TTCKF2iTQ) Stranger ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 20, 2022, 1:55am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/11 "2022-11-20T01:55:40Z")
Please explain if your reply is intended to be humorous or witty because it makes no sense otherwise. Cute it is not. ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [November 20, 2022, 1:58am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/12 "2022-11-20T01:58:31Z")
> [@ZurBob](#): > > However I am looking for some semblance of an explanation for the heat loss (or gain) of an object related to air flow and temperature differentials. Simplistic equations appreciated. The pizza you drive home from the pizza oven will never gain heat from the moment it is removed from the oven until you set it on your kitchen table. It will cool that whole time. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 20, 2022, 2:03am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/13 "2022-11-20T02:03:05Z")
Of course. The question is, how to minimalize the heat loss. ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [November 20, 2022, 2:18am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/14 "2022-11-20T02:18:52Z")
Pizza bag. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 20, 2022, 2:54am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/15 "2022-11-20T02:54:40Z")
Allright, have it your way. Under the conditions of the OP- which way will the pizza arrive at maximum temperature… #1 or #2 ? ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [November 20, 2022, 2:59am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/16 "2022-11-20T02:59:30Z")
In my opinion, without testing this, if there’s a heat vent near the floor, keep the pizza on the floor. But you’re not gonna be able to tell the difference. Say you’re at home, and someone else drove the pizza home. Your first slice will show no indication of where the pizza was during the ride home. (Unless it was in the upthread mentioned mobile pizza oven.) ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 20, 2022, 3:07am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/17 "2022-11-20T03:07:02Z")
This isn’t IMHO, and the first slice according to the OP definitely has a precedent as to the ride home. ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [November 20, 2022, 3:19am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/18 "2022-11-20T03:19:16Z")
I hear ya. But would you be able to tell where the pizza was placed if you weren’t in the car when it was brought home? The difference, if there even is one, is miniscule. That’s a fact. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [November 20, 2022, 3:45am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/19 "2022-11-20T03:45:21Z")
Read the OP. Apparently there is a misunderstanding as to who (me) delived the pizza, however the conditions are clearly stated and is immaterial as to who drives the car > BlockquoteThe difference, if there even is one, is miniscule. **strong text** > **strong text** > Unlike you ,I’m uncertain this is correct. Can you provide a citation? . ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [November 20, 2022, 3:51am UTC](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224/20 "2022-11-20T03:51:16Z")
Seriously, you’re going to have to do a test where you measure the temperature of your car in various places, and the temperature of pizzas as they leave ovens and arrive at your table. Otherwise, it’s all opinion. Have a good night. [Next page](https://boards.straightdope.com/t/pizza-delivery-thermodynamics/975224.md?page=2)