As homes are becoming increasingly crammed with more high-tech appliances and electricity costs are soaring, it’s only natural that people should be getting ideas for how to save power. Not all of these are what you’d refer to as lightbulb moments, however. Whilst some ideas are intuitive, easy to implement and work just fine (like flipping a switch), others that might seem reasonable don’t work at all and can be downright dangerous (like closing most vents in a ducted system). Yet others are radical in the extreme without necessarily resulting in any savings to speak of (like painting all radiators black).
Nevertheless, repeat something enough times, and it becomes gospel; there are plenty of popularised myths on how to save energy. Let’s debunk some by doing a walkthrough of a normal home:
So, we’re approaching Bob and Sheila’s house in the burbs. The first thing we notice is the solar panels on the roof.
Myth: you have to be disconnected from the grid to run solar.
Reality check: running solar whilst being connected to the grid works wonders. During the day, when Bob and Sheila are at work and power usage is low, the solar panels feed into the grid, in effect spinning their meter box backward as they are selling electricity to the utility company. When they get home from work and the power usage goes up, the solar panels capture the last rays of sunlight before Bob and Sheila switch to rely on grid power exclusively for the dark hours.
Myth: solar only works on sunny days.
Reality check: solar works during daylight hours, come rain, hail or shine. Efficiency goes up on bright days, true. But a significant amount of power is generated even when the skies are milky grey. The reason that the overall power generation goes down in winter has a lot to do with the fact that days are a lot shorter then.
Next, you see a cat in the window. It stares back at you from behind the double-pane glass.
Myth: installing double-pane glass is key to keeping costs down.
Reality check: the effect that windows have on heating and cooling is a function of their size, number, orientation and overhangs as well as the geographical location of the house. Installing double-pane glass is costly, and the effect is typically relatively minor. (Mind you, double-pane glass does a lot to dampen noise, but that’s another story.)
Myth: wall cavity insulation causes damp
Reality check: wall cavity insulation will most probably alleviate damp
Myth: insulating the ceiling will only cause more heat loss through windows
Reality check: insulating one part of a home won’t put more pressure on other parts.
We go inside and flip a switch in the foyer. A ceiling lamp in late Edwardian style comes to life.
Myth: compact fluorescent lamps (CFL) are those humming and flickering tubes seen in old public buildings and offices, and you need a certain setup to use them.
Reality check: modern CFL screw right into fittings for incandescent bulbs, and they generate a nice soft and warm light without any visible flickering whatsoever.
Myth: keeping CFL on throughout the day saves energy compared to switching them on and off on demand.
Reality check: by all means, CFL draw five times as much power immediately upon starting as during operation. But this initial surge only lasts for 1/120 of a second. In other words, keeping the lamp off for only a second saves more energy than is used when it’s started.
Myth: keeping CFL on saves money since they won’t last as long if you keep switching them on and off.
Reality check: the wear on the starter cathode is negligible. By switching off lamps when they’re not needed, you’ll save much, much more in energy costs than you will lose through shortened service life of the lamp. And you can save a lot by using CFL; a single 18W CFL can save about $50 in energy costs over its service life. It will also save the environment, preventing about half a tonne of carbon dioxide from entering the atmosphere.
Myth: energy-saving bulbs can’t be used with dimmer switches
Reality check: although most energy-saving bulbs aren’t compatible with dimmers, the latest fluorescent bulbs can indeed be dimmed.
Now Sheila invites us into the kitchen, where she’s preparing some tea whilst Bob is doing the dishes.
Myth: you’ll save energy by using hot tap water when boiling tea.
Reality check: heat is energy, and it has to come from somewhere. Using hot rather than cold tap water for your tea only means the water heater will use more power and that you lose heat to the pipework. It’s more economical to bring cold tap water to a boil on the stove – or, better yet, do it in the microwave or in a powered kettle. A hot water dispenser, which is not connected to your main water heater, is also a good alternative.
Myth: doing dishes by hand uses less hot water than a dishwasher.
Reality check: modern dishwashers use less hot water per load than doing dishes by hand (at least if you are to dissolve all fats), and they do not require any pre-rinsing. You can save additional energy by letting dishes air dry rather than using the machine’s drying program.
Once we’ve had tea and cookies, Bob wants to show you the etchings in his office. Your attention is immediately drawn to the sunbathing blonde bombshell in Bob’s desktop screensaver picture.
Myth: screensavers save power.
Reality check: a screensaver doesn’t save any power at all. It’s simply a file that the computer keeps running, using up plenty of electricity in the process.
Myth: switching a computer on and off several times a day will lead to significantly shorter service life.
Reality check: once upon a time, when computers were behemoths that featured soap-lubricated disks and huge mainframes, shutting them down was akin to bringing a road train to a stop. But modern computers can tolerate numerous on-off cycles a day and should at the very least be shut down every time they’re left unused for an hour or more.
Tearing your gaze from Bob’s etchings, you discover a vent in the wall ahead. Bob explains that it’s for the ducted heating, but that he keeps it closed not to waste energy by heating the office when no one is there.
Heating, venting and air-conditioning (HVAC)
Myth: closing most vents in a ducted HVAC system will save energy by only heating or cooling rooms that are in use.
Reality check: closing too many vents (over 60%) leads to excessive leakage of heat or cold through other parts of the ducts, and may lead to furnaces operating on the high-limit switch or cooling systems suffering from frozen coils.
Myth: using a portable electric heater to heat only the room you’re in saves energy.
Reality check: portable electric heaters use a tremendous amount of energy and should never be used for extended periods. In the long run, you’ll most definitely save money by ditching your portable electric heaters and installing a central heating system. You can then save big money by turning the thermostat down by just a degree.
Myth: it’s cheaper to keep heating or cooling on a low setting throughout the day than it is to turn it off when you leave the house.
Reality check: it’s more economical to stop and restart HVAC systems than to leave them running. Should you want your house to be the perfect temperature when you get home, simply install a timer switch.
Myth: you can heat or cool a room faster by setting the thermostat to a temperature that’s higher or lower than what you actually desire.
Reality check: maxing thermostats one way or the other will not heat or cool your house any faster than by setting the correct temperature, and chances are that you will forget all about the extreme setting and soon find yourself either steaming hot or freezing cold.
Myth: you can save a fortune by painting radiators matt black
Reality check: it’s true that matt-black radiators are more efficient that white, glossy ones, but the difference in efficiency is minimal.
Myth: ceiling fans keep rooms cool
Reality check: ceiling fans cool people through the wind-chill factor but do nothing to bring the room temperature down. Fans that are used to ventilate a house, such as attic fans, are a different story. By drawing in cool outside air and shunting out hot air that’s collected under the roof, attic fans can lower the temperature throughout a house.
Time has come for the special event of the evening, and we move into the lounge. You plop down on the couch and come face to face with a dusty plasma TV. A little red light tells you that it’s ready to fire up and subject you to Bob and Sheila’s two-hour home movie.
Myth: turning off appliances means stopping the power flow.
Reality check: there are numerous appliances that will keep drawing a lot of power even when shut down. Lit displays are a giveaway, but appliances can appear totally dormant whilst still consuming power to maintain internal memory or programming and the like. This power use adds up very quickly. For instance, TVs and VCRs commonly use as little as 60% of their total power consumption in active mode – the rest is wasted in standby. Set-top boxes are even worse culprits, using almost as much power when shut down as when fully active. You can resolve this issue by always switching your appliances off at the wall or installing timers that do so. Another alternative is using power boards with individual switches for each connected load.
Just when you thought that Bob and Sheila’s latest camping trip couldn’t be explored in further detail, Bob hauls out a new DVD. You assume brace position. This is the end.