Energy-Saving Equipment

These energy-saving tips are directed to people entering

LivingGreen Barrie’s Energy Saving Contest.

 

Ontario’s electricity rates are likely to continue rising. This is not political as some politicians are claiming. It is not because we chose to close coal-fired generation. It is due entirely to the unavoidable fact that most ofOntario’s electricity generating plants are old and need replacement soon.

Although the price of natural gas is particularly low right now, we cannot seriously expect that this will continue forever.

 

Getting Started – the cheap stuff

 

The first, modest purchase must be compact fluorescent (CF) lamps or, if their colour is acceptable, LED lamps. These only save about 20-30% over CFs, but last far longer. However, they are far less fragile, contain no mercury and generate even less heat. Depending on their price, they may well prove cost effective. (They may save more money over their (very long) life than their price premium over CFs).

CFs use 20-25% of the electricity consumed by incandescent bulbs and usually last 10 times as long. Even several years ago, when electricity cost $0.05/kWh, they were cost effective.

 

 

A programmable thermostat is also a great way to save energy. These allow the temperature of your house to fall at night or during the day when nobody is home. Lowering inside temperature reduces the temperature gradient between the inside of the house and the outside – thus cutting heat loss. (If the outside temperature is -10^oC and the inside is +20^oC, the gradient is 30^oC. Allowing inside temperature to fall to +15^oC, the gradient drops to 25^oC. This reduction of 17% means you lose 17% less heat.)

Set your thermostat to start heating the house 20 minutes before you expect to get up in the morning or return from work, school, etc. With a warm air heating system, the air feels warm (and comfortable) long before the walls warm up. That means you often will have left for work or school before the many tonnes of drywall warm up, and then your system will shut off, so you do not need to actually heat the house itself – only the air it contains – a further saving.

Buy power bars for places where there are clusters of “parasite loads” (equipment which continues to use electricity even when it is “off”) and switch these “on” only when you intend to use the equipment. Two examples of such clusters are the TV with its cable or satellite decoder andDVD recorder; the computer with internet modem, wi-fi system, printer, etc.

 

Larger Stuff

 

It often does not make economic sense to replace larger domestic appliances & equipment just to improve energy efficiency.  However, it almost always makes sense to ensure that appliances and equipment which no longer work well are replaced with energy efficient models. That said, replacing an old but still working refrigerator with a new model is one of the exceptions. Modern, energy efficient refrigerators reduce power consumption considerably and (depending on the old unit) could save their original purchase price in energy within 2-3 years!

 

Refrigerator/Freezer

 A big improvement in refrigerator efficiency is due to “fine-tuning” the defrost cycle. The evaporator coil (inside the unit) is cold enough that moisture condenses and freezes on it, eventually forming a thick layer of frost. The defrost cycle reverses the flow of refrigerant in the unit so the evaporator (the cold coil) becomes warm and the condenser unit (the warm coil under or behind the unit) becomes cold. When the ice melts, normal operation resumes. In old units, the defrost cycle was responsible for 60-75% of the unit’s total energy consumption. In modern units defrosting occurs less frequently and the cycle operates for shorter time periods, using perhaps 30% of energy consumption. Of course, insulation & door seals are also improved.

 

Although super-efficient refrigerators are available (eg: Sunfrost – USA & Vestfrost –Denmark), they are more costly than “ordinary” units. They are ideal for off-grid homes relying on solar panels, small wind generators & batteries. With high initial cost & the relatively low price of grid electricity, they may not make sense for most.

If this is possible, a refrigerator with no freezer in the kitchen, and a freezer in the basement make an energy efficient combination. The “all-refrigerator” has no freezer – so never needs defrosting. They are also cheaper than combination units. The “all-freezer” (I recommend the chest-type.) is also relatively inexpensive, although the two are likely to cost more than a combination unit. They tend to be better because both are optimized for their job. Combination units are a compromise between the needs of a freezer (-20^oC, seldom opened) and a refrigerator (+4^oC, often opened). By not having a defrost cycle for the refrigerator (not needed as it operates above freezing) additional energy is saved.

The separate freezer should be in the basement. There, in a cool environment (5^oC – 7^oC cooler than the house) the freezer will work less hard, and have longer “endurance” should the power fail.

Look for refrigerators and/or freezers which are “skin cooled”. These designs have the condenser coils (the warm coils) welded to the outer skin of the unit. This means that when it runs, the entire surface becomes warm. Their advantage is that the skin of a refrigerator doesn’t collect dust bunnies. These build up on the condenser coils of a conventional refrigerator, insulating it and making it hard to get rid of heat. That means the compressor must work harder to keep the refrigerator cool, using more electricity. If you keep the condenser coils of your refrigerator or freezer clean, a conventional unit will remain as efficient as the day you bought it. However, a skin cooled unit never acquires a coating of dust, so remains efficient even if you are not a good housekeeper.

 

Furnace

If your house has a working mid-efficiency furnace, replacing it with a high-efficiency model is probably not cost-effective. A mid-efficiency furnace heats a house with an efficiency of 75%. A high-efficiency furnace scores almost 95%. So you can expect to save 20% of your home heating gas use. If your gas costs you $1000 per year (not including the fixed charge all utilities impose), you can expect to save $200 per year. A new high-efficiency furnace will cost you about $4000 – so will pay off its purchase price in 20 years! It may need replacement by then!

However, if you need a new furnace, a high-efficiency model makes good economic sense. The difference in price between a mid- and a high-efficiency furnace is around $1500. The high-efficiency furnace will save you this difference in 7.5 years, making it a good investment.

When buying a high-efficiency furnace insist on an electrically efficient, multi-speed unit fan motor. Multi-speed motors are able to run at the correct speed required for different operating conditions. These use about the same amount of electricity as an “ordinary” motor when running at full power, but use far less at low speeds. For people who run their fan when neither heat or cooling is required, a multi-speed furnace will select low power for “fan only” operation. An efficient multi-speed motor can save $400-$600 per year if you run the fan continuously.

 

Windows

         Like the energy efficient furnace, high quality well insulated windows do not make economic sense if your existing windows are in good condition. However, if you need new windows for any reason, replacing them with the best is a good idea. That is because the cost of labour attached to window replacement is very high, and this labour cost is no higher if you choose the most costly window which may be 10%-20% more than an “ordinary” one!

The heat loss through a low-emissivity* (low-e), argon-filled window is ½ that of a standard double-glazed unit. Add triple glazing and the insulating value increases by another 50%. Make sure the windows you choose also have well insulated frames – avoid aluminum frames. Most modern well insulated window frames are vinyl. The best ones (may be hard to find) are fiberglass. They are sturdier and more resistant to deterioration in sunlight, although well made vinyl frames are very long lasting anyway.

* Low emissivity means the window reflects infra-red (heat) energy – keeps it in during winter and out in summer.

Glass looks perfectly transparent, but actually absorbs (& reflects) 10% of the light falling on it. About 90% of the light falling on a single window actually enters the room. With double glazing, this becomes 0.9 x 0.9 = 0.81, or about 80%; with triple glazing this falls to 73%. Since triple glazed windows are also more costly than double glazed windows, it becomes sensible to install these only in north-facing walls with double glazing in the other walls. The additional insulation is applied where it is needed most, but more sunlight enters the double glazed windows, giving those rooms additional “solar heat gain”. This “passive solar heating” more than compensates for the poorer insulation of double glazing.

 

Washing Machine & Drier

Washer:

Some 40 years ago, the “front load” washing machine began to appear in Europe. This was the industry response to the high cost of electricity and particularly water. Compared to “top load” machines these reduced water consumption by at least 50%, with a less impressive reduction in electricity consumption. Almost 30 years ago, when I bought my very first house (in England), top load washing machines were no longer available new, although they were common in 2^nd-hand shops. They “arrived” inCanada about a decade ago, although European models could be found in the “better” appliance shops.

Where a top load washing machine tops itself up with water taking over 80 litres (depending on model and capacity, this could be up to 120 litres) – and again for the rinse, the front load washer washes clothing in 15-25 litres and employs two or more rinses of similar volume – approximately 160-200 litres compared to 40-80 litres. Instead of agitating 100litres of clothing and water back and forth, a horizontal drum lifts clothes up, allowing them to fall back into the water. This gentle action uses much less energy than forcing 100kg to change direction, but the electric motor isn’t a large electricity load. On a weekly basis, the refrigerator uses far more power. Even heating the larger volume of water (if you wash in warm or hot water) isn’t a particularly large energy use.

Top load washing machines spin clothing at 300-400rpm (recent models built to compete with front loaders spin at up to 800rpm), and front load washers spin at 1000-1600rpm. Since the centripetal force which spins water out of the clothing depends on the velocity squared, 1200rpm is 9 times as effective at drying clothing as 400rpm!

 

Drier:

Modern driers label themselves “energy efficient” and do use less energy than older models, however the improvement is relatively small. The improvements are due to better detection of “dryness” in the clothing. Early driers simply used a timer which you set based on previous experience. Modern machines detect humidity in the exhaust air or moisture remaining in the clothing and stop the drying process when a pre-set value has been reached.

The “bottom line” is that evaporating moisture – what a drier does – requires energy: 540calories per gram of water. The only way to improve on that number is to dry clothing in a vacuum – a costly technology we are unlikely to see any time soon!

        Where the front load washing machine saves most energy is not in washing, but in drying! It takes far less energy to dry clothes whose moisture has been wrung out by a fast spin speed. Purchasing a washing machine with a fast spin speed is the best way to save energy required to dry clothing.

 

Air Conditioner

As a general rule, window A/C units are less efficient than central A/Cs. It is relatively difficult to insulate the hot end of the unit from the cold end. Window A/Cs are often installed in sunny windows, because they need more cooling than shady ones. An A/C unit exposed to the full glare of the sun will find it harder to lose heat than one put in a shady place.

However, a window unit cools only the space it services. If that’s the only space you want cooled, a window unit will use far less energy than a central A/C cooling the entire house!

Another option is the wall-mounted split unit. The evaporator part is installed in the room needing cooling. The condenser unit is installed on an outside wall, but not necessarily very close to the evaporator and connected to it by tubing carrying the refrigerant. This arrangement allows the evaporator to be in a sunny room while the condenser is in the shade.

If you are installing a central A/C system, try to have the condenser unit put in a shady place. The next best place would be against a wall which only gets (summer) sun in the morning. If the condenser is in the sun for even part of the day, build a shady wall of some sort for it. The cooler your condenser is, the less energy it will use.

Always ensure that the condenser unit is clean and free of leaves, grass etc. Anything which obstructs air flow will impair performance and use more energy.

If there is a reliable source of water on your property (eg: a private well or a stream), consider installing an A/C unit equipped with a water-cooled condenser. These are extensively used in grocery store refrigeration cabinets and can easily replace the air-cooled unit generally installed in the garden. You’re A/C would then be a small box in your basement with a cool water inlet pipe and a warm water (20-25^oC) outlet pipe. The cool water would need a dedicated water pump. The warm water leaving the unit could be discharged onto your lawn or back into your well or . . . A water-cooled A/C would use around 25% of the energy of a conventional air-cooled unit.

 

Stove

If you are buying a new stove, always choose one with a self-cleaning oven. A self-cleaning oven heats up to a very high temperature, charring any organic material inside, allowing this to be swept up as dust. Because of its potentially high temperature, it must be well insulated. This extra insulation will save you energy every time you use the oven.

Electric cooking surfaces employing coiled rings may be perfectly flat when made, but quickly become slightly deformed. When this happens, they do not contact the cookware efficiently, using more energy than they should. This patchy contact may also create hot spots inside the pot which may burn food.

Electric cookers with solid cooking surfaces remain perfectly flat “forever”. However, if your cookware isn’t also perfectly flat, the contact patch may be small and inefficient. Also solid cooking surfaces tend to take a long time to heat, and a similarly long time to cool, so are less controllable.

Radiant cooking surfaces do not depend on contact, but I don’t know how efficiently they heat the cookware. Radiant cookers also respond fairly rapidly to your “instructions”.

 

Induction Stove

Best of all electric stoves are induction units – first seen inEuropeabout 30 years ago. These create a high frequency oscillating magnetic field which heats ferrous surfaces within range (less than 1cm). All utensils must contain iron or steel to respond to the magnetic field. Induction cookers respond immediately to “instructions”.

Induction stoves tend to be costly, but the price will probably drop.

 

Gas Stoves

Gas stoves do not rely on contact. The hot gases from the flame contact the cookware which can be beautiful or battered. The gas flame is – of course – very easily controlled. Efficiency is pretty good – depending on the relative size of the flame and the cookware, but not excellent; just feel the heat above the pot!

 

Pressure Cooker

A particularly efficient way to cook on any kind of stove is a pressure cooker. These utensils have a screw-on lid and develop up to one atmosphere pressure. A stew or pot-roast which might take 45 minutes in an ordinary pot will cook in about 15 minutes under pressure. Since there is very little evaporation (a little steam escapes) the amount of energy required for cooking is very low.

 

Other Appliances & Devices

 

Television & DVD player/recorder

The State of California has done everybody in North Americaa huge favour. Several years ago they measured the energy consumption of a large range of appliances and devices. They noted that, while energy use when “on” was fairly standard, some used a lot of energy when they were turned “off”. In other words, some brands used a lot of electricity when “on standby”, while others did not. They challenged manufacturers & importers to match the standby energy consumption of the best units, and threatened to ban their sale in the state if they did not.

I suspect that many of the less efficient electronic devices may be on sale inNorth America, but notCalifornia. So it is worth checking. You might own a television orDVDplayer for a decade, during which time it could well use more electricity than its original purchase cost!

There are basically two types of flat-screen televisions on sale now: LCD (Liquid Crystal Display) and Plasma Displays. The LCD uses less energy than the same size of cathode ray TV (CRT), but people tend to buy flat-display TVs with larger screens than their oldCRT units, so may end up using the same amount of electricity, or even more!

The Plasma televisions tend to use more power than LCDs for a comparable screen size. Moreover, Plasma units tend to be made in larger sizes than LCDs. They may also have a shorter lifespan than LCD televisions, although the product replacement cycle is relatively short these days so lifespan may not be an issue.

 

Computer & Accessories

People are increasingly buying laptop computers instead of conventional desktop units. Even desktop computers are mostly equipped with flat screens. The flat screens are considerably more-energy efficient than the older cathode ray tube monitor. If you are buying a laptop computer, they are universally energy efficient because they are expected to operate off batteries and cannot afford to be wasteful.

Nevertheless, ask about power consumption before you buy and remember to check their standby power consumption too. Do the same when considering printers, modems, wi-fi, etc.

 

 

Motor Vehicles

 

If you are still reading, you might also be interested in motor vehicle energy efficiency . . .

Fueling motor vehicles has become expensive. We are unlikely to ever again see gasoline or diesel fuel below $1.00/litre. Even so, keep in mind that gasoline is far more expensive in almost every other country except the USA. Thus Europeans pay 2-3 times as much for their gasoline than we do, although their diesel is perhaps only 1½ – 2 times more costly. That’s why Europeans tend to drive smaller cars, and why pick-ups and SUV’s are rare.

 

The Vehicle you Have Now

Most people cannot afford to replace the vehicle they have now just because they want one which uses less fuel. If that’s you, let’s see where you are.

Most North Americans drive a vehicle with an automatic transmission – indeed, most models are not available with manual transmissions. Also, the majority do not drive a “car” but a minivan, SUV or pick-up truck – the least fuel efficient vehicles. They are less fuel efficient because they are (a) large, (b) heavy, (c) 4-wheel drive, and have (d) poor aerodynamics, (e) large engines and (f) automatic transmissions. Of course not all vehicles suffer all of the above penalties.

Consider a large vehicle like a pick-up or large SUV. Usually powered by a V-8 engine coupled to an automatic transmission, these weigh around 3 tonnes and 4 wheel-drive is almost universal in this class. According to Natural Resources Canada, if you drive 20,000km per year (typical for Canadians) you can expect to burn 3000 litres of fuel for a total cost of around $3750.

A more modest vehicle such as a Honda Accord or Ford Fusion might cost $2000-$2500 to fuel while a small car like a Mazda 3, Ford Focus or Honda Civic would burn $1500-$1800 of fuel per year. Clearly, fuel consumption depends on driving style and traffic conditions.

 

First Steps

The first steps to reducing fuel consumption are the usual ones of ensuring the engine is properly adjusted, tires inflated to the recommended pressure, and any roof rack or other accessory removed unless actually required. Roof racks left on year-round increase fuel consumption by about 10%. If you have heavy things in the trunk, leave them home unless they are actually needed. Extra weight must be accelerated along with the car and more fuel is burned to do this. If you use snow tires in winter, remove them when the snow goes. Snow tires have higher rolling resistance than summer or all season tires. Winter tires have a soft rubber compound which tends to wear rapidly on hot pavement. In winter the roads are cold and this is not a problem.

 

Driving Style

The automatic transmission “loads” the engine when the vehicle is stopped. When you take your foot off the brake, the vehicle will move forward, and may reach 15km/hr even if you do not touch the accelerator. When you are stopped, the engine actually consumes more fuel than it would if you allowed the car to roll along. Do not allow your car to idle un-necessarily. If you must keep the engine running (eg: to keep the car warm or cool), do not leave it in “Drive” – put the transmission in “Neutral”; this takes some of the load off the engine.

You can expect your car to use 1.5litres per hour while idling – and more than that if left to idle in “Drive”. Think about that when you are stopped in traffic or lining up for access to the fast-food takeout window!

In general, the more vigorously you accelerate, the more fuel the engine will use. Gentle acceleration improves fuel economy. Probably even more important is judging your braking. When driving in moderate traffic, try to adjust your speed to avoid coming to a full halt. That way your transmission will stay in a higher gear, using less fuel. If you see a red light ahead, slow down well in advance with the intention to reach the intersection as the light turns green and the other cars ahead of you begin to move – less acceleration, less fuel burned.

On the highway at around 80km/hr, about 75% of your car’s fuel is burned to overcome aerodynamic drag. Aerodynamic drag rises as the square of velocity. So the drag at 85km/hr is double that at 60km/hr; and at125km/hr drag is double that at 90km/hr! Above 110km/hr, aerodynamic drag is responsible for 85% of fuel consumption. Leave yourself a little more time and save money!

 

Car Air Conditioning

A modern car behaves a little like a greenhouse – it becomes really hot parked in the sun. This is largely caused by the steep slope of the front and rear windows. Many years ago, windshields were more vertical and less sunlight entered the car.

Countering solar heating can be accomplished by either opening the windows or by running the A/C. Opening the windows increases drag, using more fuel. The A/C is powered by the engine, also using fuel. In general, at urban driving speeds, the A/C will use more fuel than driving with open windows. At highway speeds, the A/C should use less fuel than open windows.

When you get into a parked car in summer the interior, including the seats, will be really hot. With the seats transferring heat to you, you will tend to run the A/C on a high setting for a long time – until you can cool down the seats. If you managed to park in the shade, you will feel less uncomfortable and run the A/C at a lower setting, saving fuel. If shade is available, don’t park where the shade is now, but where you anticipate that the shade will be when you return to the car!

If it is not likely to rain, open all the windows slightly. The car will be considerably less hot inside when you return. If there is nothing in the car to steal and there is little chance of vandalism, consider leaving the windows completely open.

 

Your Next Car

 

If you are serious about burning less fuel, consider the following points in no particular order:

 

– Do you really need a large vehicle? A small car burns less fuel than a large one. You can always rent a large vehicle (minivan, pick-up, etc) for the few occasions when you really need one

 

– If you do a lot of highway driving, look for a car with a low Coefficient of Aerodynamic Drag (C_d). Have fun with the sales people by asking them for the C_d of their models. The information is available, but they will not know!

 

– If you drive mostly in a city, look for light weight. The heavier the vehicle, the more fuel is needed for acceleration!

 

– Do you really need 4 wheel-drive? The machinery associated with 4WD increases vehicle weight and creates more friction – both increase fuel consumption. Instead, buy snow tires for winter and take them off in summer – a far cheaper option than 4WD which yields as good or better traction than 4WD without winter tires.

 

– Do you really need an automatic? In almost every case an automatic uses more fuel than a manual transmission. They are particularly thirsty in congested traffic. Manual transmissions are more fun and tend to keep you more alert to driving conditions.

 

– Hybrids claim excellent fuel consumption, but

(a) don’t operate as hybrids until they are warmed up, so don’t perform well in short journeys, particularly in

winter. (Hybrids work best as urban taxis; the engine is kept warm, & the vehicle operates in traffic where its unique capabilities can be fully used.)

(b) cannot use their hybrid capabilities in steady-speed highway driving.

(c) are costly to purchase and may not save more money than the premium you paid to buy it.

(d) batteries have a lifespan. Will a canny 2^nd-hand buyer reduce his/her offer on the grounds that the battery pack             may need replacement soon? (Hybrid car batteries cost around $4000 to replace!)

(e) are very sensitive to driving style – more so than a conventional vehicle. (Some of the hybrid’s fuel economy depends on its

          ability to capture some of the vehicle’s kinetic energy on braking. On light braking, the electric motor works as a generator as it slows the car, recharging

          the battery. If you brake forcefully, the friction brakes are used and that kinetic energy is lost as heat – gentle driving is rewarded!)

 

– All-electric cars work well in urban driving, particularly in summer (Batteries deliver their best performance when warm.) In

winter, some of the battery’s energy must be used to heat the vehicle greatly reducing its operating range. Cold

temperatures also reduce range. Also, batteries have a lifespan and the vehicle’s 2^nd-hand value may be less than

you hope or expect because of this. (All-electric car batteries cost around $10,000 to replace!)

 

– Consider a diesel. Overall fuel consumption is as good as a hybrid. They are less sensitive to driving style than a gasoline-powered vehicle – much less than a hybrid. Unfortunately, very few vehicles are available as diesels in Canada (70% of all European cars are diesel powered!) The only manufacturer offering as wide selection of diesels is VW; Mercedes offers a few as does BMW, but these are very expensive. In 2014, Mazda and GM will be offering some of their cars with (clean)