Request for info on walk-in freezer door hinge (link for video included)

[John2004]

Hi everyone,

I have a question about the door hinges on a large walk-in freezer used to store product for the frozen section of a large Grocery store.

I noticed that when opening the freezer door, the entire door moves up about 3/4 to 1 inch or so. The hinges are designed with a helix / lead-screw type of system that gradually raises the door as it is opened. Can anyone please tell me why the door hinges are designed this way ? I have a few guesses below, but I would like to know the real reason.

Several things crossed my mind..

1. The door is so heavy that something is needed to help keep the weight off the lower end portion of the hinge to keep it from wearing out.

2. The hinge is designed so that the weight of the door helps the door close. However, if the hinge is designed so that the weight of the door helps it close, then it would seem the weight of the door would also make the door more difficult to open. I cannot tell any real difference in the force required to open or close the door.

3. It is desirable to have the door raise as it is opened to help keep the bottom of the door from freezing at the floor in case water or moisture gets in there and freezes.

4. It is desirable to have the door raise as it is opened to help keep the weather stripping at the bottom from wearing on the concrete floor.

Also, can anyone tell me if the fans are typically supposed to shut off whenever the door is opened on these types of freezers ? You would think the fans should be off when people are inside.

Both links below are the same video, just in different formats so you can download whichever you need.

5.32 MB WMV video of the door hinge (for windows media player)

https://www.mediafire.com/file/ha0z37ao4y176yz/Walk_in_freezer_door_hinge.wmv

26.36 MB MP4 video of the door hinge (for players other than windows media player)

https://www.mediafire.com/file/g671739c0wweb60/Walk in freezer door hinge.mp4

Thanks for your help.

John

 

[SwinnyGG]

I think it's some combination of these:

2. The hinge is designed so that the weight of the door helps the door close.

4. It is desirable to have the door raise as it is opened to help keep the weather stripping at the bottom from wearing on the concrete floor.

 

[Compositepro]

Those hinges have an helical cam surface that the weight of the door rests upon. If you open the door fully, the doors will come to rest on a flat, and stay open. But if only partly open the door is self closing. The lowering of the door as it closes allows for the bottom door gasket to compress and seal against the floor without rubbing on the floor when it opens.

 

[John2004]

Thanks for the info.

I was just curious why the hinge would be designed this way. I guess this is a way of making sure the bottom of the door seals when it is closed, and does not drag or wear as it is being opened.

 

[zeusfaber]

Hinges like that are quite common on domestic internal doors (Google "rising butt hinges") - usually when a door opens into a room with a carpeted floor. There, the main reason is to stop the bottom of the door rubbing on the carpet so your thought about protecting the bottom seal sounds sensible.

A.

 

[Compositepro]

This style of hinge is also often used in commercial refrigerator doors where there is no floor seal, only face seals. The self closing behavior that stops when the door is fully open is the main benefit.