Here is a look into our galley freezer this spring prior to defrosting the evaporator plates. The last time we defrosted was in the fall, so the build up you see is the result of the last six months (this totaled about half a quart/liter of liquid when we finished).

Frost acts as an insulator and reduces the efficiency of heat transfer. Whether you have an evaporator plate system or holding plates, even 1/8" (3mm) of frost will have a major negative impact on compressor run time and the electrical consumption.

We use this 1600-watt industrial heat gun to defrost the plates, but a hair drier will work too. What you do not want to do is use anything sharp to chop off the build up. This is particularly true with evaporator plates, which can be easily punctured. We run the heat gun at the highest setting, waving it back and forth about 6" (150mm) from the plate surface.

Here is the freezer and plate frost free, dried, and ready to be reloaded. Note the space between the evaporator plate and interior freezer walls. This 3/4" (19mm) allows air to circulate, making the system more efficient (but at a loss in volume). Those stainless rails running vertically help to position baskets away from the plates.

Top loading freezers are more efficient in that they lose less cold air when open. However, they are open longer because it is harder to find what you want - so on balance, top and side-loading freezers work out about the same in overall efficiency. You can see the baskets we use to separate food categories. These make finding what we want easier, but are less efficient in terms of how much stuff can be crammed into the freezer space.

Wind Horse has a second freezer in her "basement" which is front-loading. We use a combination of baskets with some items loose. This freezer is only accessed on a weekly basis, whereas the galley freezer is used daily.

Test your powers of observation. What is different here? Notice the clear plastic barrier? This is made from 1/4" (6mm) Plexiglas and is used to reduce cold air spillage, and to help contain freezer payload when full. We often fit clear plastic barriers like this to front loading freezers.

We should probably say something about the Frigiboat/Danfoss system we are using. These little compressors - one for each freezer and fridge (3 total) - have proven to be reliable, and very efficient. We would not go back to the approach we used in the past - with holding plates and big compressors. The Frigboat/Danfoss gear is only as efficient as our best holding plate systems, but they are quieter and a fraction of the cost.