Why my freezer gets frost build up on the inside walls.

There are a few reasons that cause frost to build up on the inside of the freezer walls.

1. If you are putting stuff in the freezer that is too hot, or the container is wet it causes an increase in your freezer humidity levels. Even with good airflow, increased humidity levels can cause frost to form on the side of the freezer walls. Make sure you allow time for items to cool to room temperature before putting them in the freezer.
2. If you have people who stand with the freezer door open for long periods of time and your house is warm it can cause frost to build up on the inside walls. Be quick about getting what you want and shut the door quickly.
3. If your seal has got something stuck on it like dirt or food and is not sealing properly, this can cause frost to build up as well. Wash the seal with warm soapy water and dry it off good. You can also apply a little Vaseline with your finger, not a bunch, just a light layer to the seal will help soften the seal and make it stick and seal better.
4. If the seal is badly worn this will cause the cold air to escape and the hot air to enter, causing frost to build up on the inside. Replace a bad seal with a new one to fix this problem.