Originally posted on December 6, 2012 at 12:05 PM
American homes were never particularly designed for energy or water efficiency. Party of this is because in the wake of World War II with a national manufacturing industry ramped up for war and needing new customers for output, electrical appliances came cascading off the assembly lines in hitherto unheard of quantities. Energy using units such as refrigerators, stoves, water heaters, furnaces were manufactured as isolated entities without regard for anything else which might be going on in the modern home. So things stand mostly today.
Whether or not you’ve ever thought much about the efficiency of appliance design or the logic of operating household energy functions as an integrated system, you may have noticed certain illogics in how our appliances operate. For instance a refrigerator on a hot summer day, while chilling drinks and ice cream for us, blows hot air (usually out the bottom or radiating out the back) at an altitude calculated to be most irritating. Refrigerators used to have their radiating coils on top where the heat would rise toward the ceiling and the system wouldn’t need to labor to counteract it’s own waste heat. Bottom-blower fans were more aesthetic though so fridges were redesigned. During winter we fight against heated room temperature to chill our leftover turkey and cranberry sauce when there’s all that lovely cold outside, doing doing much but sucking heat out through the walls!
A note about how refrigerators work. A compresser squeezes a fairly large volume of working fluid, formerly Freon, but many other substances also work, into a much smaller space. This makes the substance heat up. The heated up substance or Working Fluid is cooled (hence the hot air out of the fridge vents) and when allowed to expand again the substance is much colder than before. This uses up around six KWH of energy per day, costing around sixty cents. Meanwhile our water heaters electric or gas, are independently turning out heated water for showers, dishwashing, laundry. The colder the groundwater coming into the home, the harder the heater must work.
It’s possible to combine the functions of refrigeration and water heating. Patents to this effect go back to at least 1975. Remember our substance going through the compressor and the heated output which must be cooled before reexpanding? The basic idea is to run the heated substance through coils located in the bottom of a water heater tank. Waste heat from the fridge goes into the bathwater then the working fluid is reexpanded to cool the fridge. The colder the ground water the better the fridge would operate. The warmer the ground water is, the less the heater needs to operate so if we can accept somewhat warmer fridge temperatures we can run our fridge with less power. Either way we save money.
The idea is an integrated stand-alone unit with the fridge on the bottom and a water tank on top. Insulated hoses could run directly from the tank to hot taps in kitchen, bathroom, laundry room. The same electricity which heats your water also runs your fridge. Such units would be ideal for vacation homes as well and could save a lot of money in new construction and would also be very appropriate for old construction. A unit such as this could be built by a small manufacturing firm or even by a sufficiently skilled do-it-yourselfer. The fridge/water heater would actually be an “intelligently designed” integrated household system. I want one; in blue. Why blue? Well according to my ceramic materials processing Prof Osgood J. Whittamore Jr. the “slip” or liquid clay used to enamel steel which forms the body of fridges or stoves, is most commonly blue in color but because most home makers preferred white appliances, several coats of white material must be added to cover the blue, bringing up manufacturing costs due to successive firing and making things heavier besides. Blue is good enough for me!