Chest Fridge

Why Consider Alternative Food Refrigeration?

Aside from home heating and cooling, refrigeration is one of the largest energy hogs among home appliances. Most refrigerator/freezer units, even with the Energy Star rating consume at least 1500 Watt-hours (or 1.5kWh) of electricity every day (in a 24-hour period). At electricity prices of $0.10/kWh, this translates to about $0.15/day, or about $55/year. Not a big deal. However, if you are concerned about the amount of mercury and other pollutants our coal-fired electricity plants are pumping into the atmosphere in order to power your home, then you may consider this ultra-efficient alternative to drastically reduce your overall carbon footprint. 

Is it really that much more efficient than a regular fridge? Well, this is an interesting question. It turns out that using a chest freezer operating at chest fridge temperatures does have some inherent efficiencies over a convention upright freezerless refrigerator that gives at least a 50% improvement in efficiency when you compare energy consumption per cubic foot of volume. The improvements are due to 1) extra insulation as most chest freezers have about 2.5" of insulation; 2) reduced losses from air change when you open the door because cool air doesn't rush out the bottom; and 3) simpler refrigeration configuration with condenser coils wrapped around the body of the chest. So, if we are talking about kWh per unit volume held at a given temperature, the chest freezer consumes less by a factor of 1.5-2.0 (50% - 100% improvement in efficiency) over its upright counterpart.

The Lifestyle Adjustment:

It turns out that converting from an upright fridge to a chest fridge requires a significant adjustment in how you store, organize, and retrieve goods from your fridge. We have found half-pint, pint, and quart size wide-mouth canning jars to be the best containers for left-overs and air-tight storage in a chest fridge. These are easily stackable, can be labeled with a write-on magnet that sticks to the lid, and fit quite well into milk-crate size baskets.

Additionally, we have found that it is possible to get an even larger effective improvement in efficiency by learning to live with considerably less volume. Instead of going with a 17cu ft upright fridge that would consume about 372kWh/year, we are using a 5.5cu ft chest fridge that uses about 73kWh/year, a factor of 5 reduction in consumption.

How to Make the Switch:

The conversion is quite simple. Buy a new chest freezer that fits into the space where your old fridge was. We recommend the ones that feature an aluminum interior to prevent rust from moisture, and with a built-in bottom drain. Buy an external thermostat available on-line through beer brewing suppliers. Plug the chest freezer into the thermostat, thermostat into the wall, and dangle the temperature probe over the backside of the door into the chest freezer. Set the thermostat to your desired temperature, and you are there. Some other minor refinements including creating some shelving inside your chest fridge which can be done with milk crates, pastry shelves, and other plastic totes. You may also run a hose out of the chest's drain and into a small jar to catch the water that condenses out into the bottom of the fridge. Alternatively, a towel in the bottom of the chest absorbs accumulated moisture and should be washed and changed periodically. We have found that the high moisture of the chest fridge is conducive to mold growth, so periodic cleaning/sanitizing of the surfaces and shelving is required.