» Residents have waterbeds...
but are not careful to make them up each day. That results in significantly increased energy cost! A typical waterbed costs about $10 a month to heat if it's made up each day with heavy covers that hold its heat. If left uncovered the heating cost can double. Smaller water beds cost less to heat than larger: A queen size bed's heating cost is about 22% less than a king size. Whatever the size, it helps to insulate the bed's edges and bottom with polyethylene foam, polystyrene foam or even layers of corrugated cardboard.

» A resident requires the use of oxygen...
and unfortunately, the energy cost to run these compressor systems is surprisingly high.

» There's a dehumidifier running nonstop, draining through a hose to the outdoors...
and the basement area being "dried" is itself wide open to the outdoors! Admittedly, this is a rare finding, but let's look a little more closely at dehumidifiers. They remove water from the air. So does your air conditioner. But a dehumidifier heats the room in which it sits, just as your refrigerator does! Nevertheless, for some homes it's a very good weapon in the battle against mildew. Have you noticed how dehumidifiers all seem to have about the same size pan for water collection, but have widely different capacities for water removal? The capacities are usually expressed as pints of water removed in a 24 hour period at some standard temperature and humidity. A "bigger" dehumidifier, with a larger compressor and higher operating cost per minute of run time, removes water from the air faster, but generally less efficiently. If you're catching the water in the pan underneath, you'll need to empty it more frequently to keep up. If you're draining via a hose, there's no emptying necessary, but just be sure that the area you're attempting to dry isn't like the one above, open to the outdoors! That was a real finding by one of our auditors. The resident was using a high capacity dehumidifier, the room air was damp as ever and the monthly cost was extraordinary.

» We experience a dry period, maybe in May or June (like the one we are having now)...
and water bills rise. It's all that lawn watering. Home lawns are often over-watered. At normal pressure, a 5/8" garden hose delivers about 10 gallons per minute. Thirty minutes of unneeded watering wastes 300 gallons of water! Water waste costs you money and does not improve the health of your lawn.

» Windows on the southwest or west side are fully exposed to the setting sun...
and they need external and internal shading. In newer Florida homes sun entering the windows accounts for about 20% of the air conditioning load. In older homes, it can be as much as 30%. Use of interior shades, drapes or blinds reduces heat gain across the windows by about 20%. External shade (trees, awnings, sun screens) works even better. Some newer, high tech windows have special tints or films that reduce the amount of heat transmitted across the window into the house. Most window manufacturers now offer high-tech windows with low-E coatings. A low-E coating is a microscopically thin, virtually invisible, metal or metallic oxide layer deposited on a window. In a double paned window the coated surface may be either the outer side of the inner glass or the inner side of the outer glass. In Florida the latter design works better. The coating acts to suppress radiative heat movement across the window by reflecting heat back into the home during cold weather and back to the outdoors during warm weather.

» The electric meter was misread...high or low. Yes, it happens rarely. Because the meter registers kilowatt hour usage cumulatively, the billing self-adjusts the next month, but not without some momentary alarm for those concerned.

» College students living away from home for the first time move into an off campus house or apartment in August...
and the first utility bill has a way of getting high. It seems to relate to that whirlwind of initial activity that happens to coincide with brutally hot weather: Moving in, cleaning, parties, friends over, door open, thermostat set too low, etc. (See #99 below)

» The small pump on a water heating waste heat recovery unit runs nonstop...
whether the air conditioner is running or not. This can get pretty costly, especially if the water heater is a long way from the air conditioner's outdoor condenser.

» There's hot water in the toilet! Six words that mean trouble. For years we teased one of our energy auditors who insisted he had found this - no one believed him. Then two others discovered the same thing.

» The house is very large...
and so is the cost to cool it. There's more volume to heat and cool. Larger homes generally have higher utility costs, all things considered.

» Bad meter...
Notice how late on the list this one appears. It's about the last thing an experienced energy auditor suspects to be the problem. How often is an electric meter too fast? It's hard to pry a definitive statement out of the folks in the Electric Department's Meter Shop, but not because they have anything to hide. After a long pause, their answers usually come out like these: "It's mighty rare". "How often is one fast? One in a million? Maybe one in 100,000?". "Once in a blue moon". "There was one a while back that was damaged by lightning, but it was running too slow, not too fast." "Over the past 18 years I can't think of even one meter that tested fast. We've found some slow, or stopped, but not fast". The fact is, most meters run very slightly slower as they get older. When a meter fails, it doesn't speed up, it stops. (By the way this is true for gas and water meters as well.) Here's what happens when you request an electric meter test: Your old meter comes off the wall and a new, recently certified-as-accurate meter takes its place. The old one is returned to the Meter Shop where it's tested by the Electric Department's meter repair technicians. They bench test it on an RFL 5800 Meter Calibration System, a $40,000, state-of-the-art "watt-hour comparator". It's no surprise for older meters to test a shade slow. The old meter is either adjusted and put back in service, or retired.

» "The roomate effect"...
Happens to college students in off-campus housing. Each roomate has a different level of thermal comfort and a different level of concern for energy conservation in general. The energy practices of the least concerned and least conserving individual often become the norm for all residents

» Office in the home...
This is becoming more common. Here's the power draw of some selected home office accessories, taken from a 1993 article in Home Energy:

How much this costs depends on activity levels. Suppose the copier, printer and fax machine are idle 23 hours and active 1 hour each day: Together with computer and monitor (let's say they are active 24 hours/day), monthly cost is about $15.