Is it possible to create a completely sealed room where a door can't be opened?

  • Context: Undergrad 
  • Thread starter Thread starter Blue Nuances
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the hypothetical scenario of creating a completely sealed room where the pressure difference prevents a door from being opened inwards. Participants explore the physics theories applicable to this situation, including pressure dynamics and temperature effects, while considering practical implications and real-world analogies.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether a completely sealed room can be created with high enough pressure to prevent a door from opening inwards, suggesting the combined gas law as a relevant theory.
  • Another participant argues that a pump would not be able to remove all the air completely and suggests that high pressure could damage the door.
  • A later reply clarifies that the focus is on creating a pressure difference rather than removing all air, questioning the feasibility of this scenario.
  • One participant compares the situation to an airplane, noting that it requires very little pressure to create a significant force on a door.
  • Another participant discusses the pressure difference needed and raises questions about the temperature variations in airplanes compared to the proposed room scenario.
  • One participant calculates that even a small pressure difference (0.5 psi) could result in a significant force required to open a typical door.
  • Another participant emphasizes that temperature differences are only relevant if heating is used to generate pressure, questioning the necessity of temperature increases in the context of sealing the door.
  • A participant warns against using temperature to seal a door, suggesting that poor ventilation would create a vacuum effect instead, and highlights the potential dangers of such an experiment.
  • One participant provides a real-life example of the pressure effect experienced when trying to open a car door underwater, illustrating the concept of pressure dynamics.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the feasibility of creating a sealed room with a pressure difference sufficient to prevent a door from opening. There is no consensus on the practicality or safety of such a scenario.

Contextual Notes

Participants note limitations related to assumptions about air removal, pressure generation, and the physical properties of materials involved. The discussion reflects uncertainty regarding the exact conditions required to achieve the proposed scenario.

Blue Nuances
Messages
4
Reaction score
0
Hi, this is my first post here so mods, if my question would be better directed somewhere else, please do tell me.

My knowledge of physics is only up till high school so I would greatly appreciate it if I could have your opinion on the following hypothetical situation:

Is it possible to create a completely sealed room (say, 4m by 4m by 3m) with a pressure so high such that you cannot move a door which opens inwards, into the room?

- Which physics theories would apply to this situation? I could only think of the combined gas law.
- What is the theoretical temperature which is required to generate this pressure? Assuming that an adult would be the person to open the door?

Thank you.
 
Science news on Phys.org
You could use a pump but it would never remove all the air completely.I also think that the pressure would rip the door to shreds anyway.
 
ZxcvbnM2000 said:
You could use a pump but it would never remove all the air completely.I also think that the pressure would rip the door to shreds anyway.

Thanks for replying!

I'm thinking of a situation where the pressure inside the room is so high compared to the pressure outside the room, that a person wouldn't be able to open the door inwards. In that case, a pump to completely remove the air within the room wouldn't be necessary, right? Would that still be possible?
 
Sounds like an airplane to me!

Thing is, it requires very little pressure. It can happen in a poorly (airflow) balanced room/building.

Just take the force you want the door to resist, multiply by 2 and divide by the area to get the pressure needed.
 
Last edited:
russ_watters said:
Sounds like an airplane to me!

Thing is, it requires very little pressure. It can happen in a poorly (airflow) balanced room/building.

What would the pressure difference between the inside of the room and the outside realistically be?

Also, in an airplane, the temperature difference between the interior of the plane and its environment varies by more than just a few degrees celsius, doesn't it?
 
It doesn't take much pressure. A typical door is about 8 ft by 4 ft, which is about 4000 square inches. So even 0.5 psi would take about 1 ton of force to open.
 
... And temperature difference isn't relevant here unless you are trying to generate the pressure with heating.
 
russ_watters said:
... And temperature difference isn't relevant here unless you are trying to generate the pressure with heating.

Let's say a heater is placed within the room to increase the pressure. How much more would the temperature need to increase in a room that is 4m by 4m by 3m?
 
Blue Nuances said:
Let's say a heater is placed within the room to increase the pressure. How much more would the temperature need to increase in a room that is 4m by 4m by 3m?

To do WHAT?
 
  • #10
The temperature outside an airplane is often at arctic temperatures like -50C.
 
  • #11
this sounds like a suicide project

clearly, higher temp = more pressure but don't try raising temp to seal a door. like stated earlier, poor ventilation will have the biggest effect by creating a vacuum in your room. youd need to pair this with an extremely windy day lol

if its truly 100% sealed, let's just say youd be hurting your body before you use temperature to seal the door.

think of a car's cooling system if youre good with automotive at all. the coolant in a car usually operates from 185-210* F and that's around 13-16psi. its a lot of pressure but your heater won't go up to those temps

and you can't just think of sealing a room, raise temp and base pressure off that. your walls are going to sponge/transfer the heat so even if you use the right temp and math to get the pressure, reality will prove your numbers wrong
 
  • #12
This effect can actually be seen in real life. For example, it is impossible to open a car door underwater (with human strength) without winding down the windows, because the pressure of the water outside is bigger than the pressure of the air inside. This effect is magnified by the fact that you can't compress liquids.
 

Similar threads

Undergrad Pressure: Sealed bottle physics
  • · Replies 29 ·
Replies
29
Views
5K
Entropy of a sealed room with an open-door refrigerator
  • · Replies 5 ·
Replies
5
Views
1K
High School How to estimate the heating power of warm air entering a room?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad Effects on Engine Overheating and Pressure Dynamics
  • · Replies 4 ·
Replies
4
Views
3K
High School How can I change the airflow under a hotel room door to the hall?
  • · Replies 14 ·
Replies
14
Views
4K
Door Grilles/Pressure relief grilles in hospital rooms
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad How can visible gas bubbles remain intact inside frozen water?
  • · Replies 8 ·
Replies
8
Views
2K
High School Energy seems to disappear when gas is compressed?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Trying to wrap my head around gas turbine thermodynamics
  • · Replies 5 ·
Replies
5
Views
4K
Graduate Is Maxwell's Demon Limited by Energy Required for Door Movement?
  • · Replies 8 ·
Replies
8
Views
3K