GREENer HOUSE

His                                          Hers

I received an email today from someone asking whether Jetmasters use a lot of gas. It’s a question that I answered best a few years ago when I wrote about heaters for Fairlady magazine. So I’m reprinting that article below.  Other GreenerHouse posts on heating can be found here and here.

Warm House, Cool Planet

The battle of the sexes erupted in our lounge one recent winter when our creaky Westpoint oil heater finally conked out. To replace it, my wife demanded something that flickered yellow, glowed orange and suggested romance. I insisted on something calculated to maximize efficiency, easy on my green conscience and not too hard on my wallet over the long-term, either. In the end, there was only one way to keep the peace: His and hers heaters.

Chilly consumers today are faced with a wider range of home heating options than ever before. You can plug in convection heaters, oil-filled radiators, or fan heaters. You can light anthracite in a fireplace, a convector, or an airtight stove. You can install electric heating wires underfloor, undertile or undercarpet. Gas heaters may be radiant or convective, flued or unflued, rollabout, built-in or freestanding, and any combination of the above. To add to the confusion, what looks cheap today may cost more down the line. And more importantly, what appears clean may force the environment to pay a price for generations to come.

South Africans have made electricity their first choice for home heating, encouraged by some of the cheapest kilowatts in the world. But Eskom derives 88 percent of its power from the dirtiest of fossil fuels: coal. Think of the electric main arriving at your house as a little pipeline of coal slurry. For every 100 rand on your electric bill, more than a quarter tonne of carbon dioxide has been pumped into the atmosphere on your behalf. The Australian Consumers’ Association has calculated that in equally coal-dependent Sydney, where winters are a little cooler than Cape Town’s, but considerably warmer than Johannesburg’s, warming a house with electric heaters can contribute 3.4 tonnes of CO2 toward global warming each year, far more than any other energy source they investigated.

In the resulting global greenhouse, the last of Mt. Kilimanjaro’s glacial ice will melt in 2015; South Africa’s drought-plagued maize crop will fall by a fifth in the next 50 years; and rising temperatures will trigger massive extinctions of sensitive fynbos flowers. It may be too late to stop some of these catastrophic projections from becoming reality, but I would rather not have them on my conscience. I moved down the list to other heating options.

Ironically, burning anthracite coal at home can produce far less carbon dioxide than heating with electricity. It depends on how you burn it, however. Throw the nuggets into a hole-in-the-wall fireplace, and up to 90 percent of your heat and coal-budget goes up the chimney. This black option makes electricity look positively green. Modern, tapered fireplaces and convectors improve the heat output, but the cleanest, most efficient option is an airtight heating stove. These pricey heaters—nearly R8 000 for Franco Belge’s popular Belfort stove—combine high-tech inner construction with an old-fashioned, cast-iron exterior to convert 65 to 85 percent of coal energy into heat for the room. In contrast, three-quarters of the coal energy that goes into electricity is lost in generation and transmission.

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Before                                         After

I have always considered our refrigeration set-up to be rather modest. No bar fridge. No chest freezer. No massive side-by-side fridge-freezer. (That’s the least efficient configuration; freezer on top is the most efficient.) We manage to keep five people fed with a single, rather small, 300 litre LG refrigerator-freezer that receives an A rating for energy efficiency from the European Union.

So I was a little bit disappointed when I used my Watts Up meter to measure the actual consumption of this appliance recently and found that it was chewing through 2.5 kilowatt hours a day, about 10 percent of my household consumption. When I researched the issue on the internet, I saw numerous references to dirty coils lowering efficiency, so I pulled the fridge out of its slot in the kitchen. I feel a little embarrassed to publish the photograph above, because it is a stiff indictment of our housekeeping, but you have to see it to realize that when I say years of dust had clogged the vents, I really mean it.

After a quick vacuuming, I was eager to test whether the improved air-flow to the coils would lower my electricity consumption. I measured at night so that the comparisons would not be thrown off by family members opening the doors during the day. Consumption fell by more than 17 percent after the fridge was freed of its dust blanket. Since the condenser works much harder during the day than at night, the true improvement may be much larger. I have now set an annual memo on my Outlook calendar to remind me to keep the vents clean and my refrigerator green.

Watts up? Pro meter

I have a new toy. It’s called a Watts up?, and it will measure the watts used by anything with a plug, up to about 2200 watts. It will calculate watt hours, as well, which is essential for appliances that cycle on and off. Watt hours are what you and I and the environment pay for. Quite simply, a 1 watt device running for an hour has used 1 watt hour. The electricity meters on houses measure kilowatt hour, or 1,000 watt hours, and that’s what we pay for in our electricity bills. For each kilowatt hour we use, Eskom sends about 1 kg of carbon dioxide into the atmosphere.

I’ve been playing with my toy for about a week, and I now have a good idea of how much electricity is used by what.

Here, in no particular order, are some of my findings.

•Washing Machine: 214 watt hours for full load. My mother-in-law always believed that clothes fare better in a cold wash, so we have always set our washing machine on cold. (Who am I to argue with my mother-in-law?) The washing machine is rated at 2360 watts, so it might burn out my Watts Up meter if I tested a hot load, but my calculations are that if we washed in warm or hot water, that number would rise by 10 times.

•Philips 29-inch CRT Television. 73 watts on, zero on stand-by. You won’t find a big flat-screen LCD or plasma TV that uses anywhere near that little.

•DSTV Personal Video Recorder PVR: 29 watts. This is worse than it looks. Forget the fact that the PVR tells you it’s “going to sleep,” or “coming out of sleep.” It uses 29 watts all day every day, three-quarters of a kilowatt hour per day, 270 kWh per year. What irritates me is that the designers could have engineered a PVR that powers down the hard drive when it’s not needed, as my laptop does every time I stop using it for several minutes.

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This week, my favourite little Rinnai gas heater stopped working when load shedding began on a cold night. It may use gas, but it also has an electric fan so it isn’t Eskom-proof. I’ve been looking at alternatives.

Last year at about this time, I wrote an overview of home heating options. In it, I ranked an open fireplace heated by gas 8th out of 11 options, well worse than average. This is because gas may burn cleanly, but any open fireplace loses most of its heat up the flue.

I failed to mention then that I own a Jetmaster open gas fireplace. In the past, I only used it a few times a year for ambience when we had guests, but I’ll have to use it a lot more during load shedding this winter since it’s my only heater that runs without electricity. That’s a problem, because LPG has risen in price from R367 for a 48 kg bottle when I installed the Jetmaster in 2001 to R820 now. And according to my own ranking, I’ll be using one of the least environmentally friendly options around.

When I first installed the Jetmaster, I briefly considered a wood stove, but I knew that wood burning was a source of carcinogenic particulates, and I didn’t see how wood made sense in a semi-arid country with so few trees.

I’ve learned two important things since then. First, I got a quick lesson in urban forestry a few years ago when I had to remove a giant dying oak from my garden. It broke my heart to see tons of potential firewood being carted away by a tree-feller who told me he was taking it to the dump. (The trunk and limbs were too large for me to split.) The logs would ultimately decompose, releasing greenhouse gasses without benefiting anyone. I called around and learned that some other tree-fellers cut and split the wood they retrieve to sell for firewood. In the future, I would only use a tree-feller who recycled this way.

Johannesburg is sometimes called the world’s largest urban forest. I suspect that this is hyperbole that could not be proven, but the fact is that the city creates enough firewood to heat many more local homes than it currently does. (Though not all of the homes, of course.)

The second education I received was when I began researching the latest wood stoves and fireplace inserts. They aren’t just better than open fireplaces, they are unrecognizably better. An open wood fireplace loses 90 percent or more of its heat up the chimney and releases about 50 grams of particulates per hour. Anyone who has read what I have writing about diesel emissions in the Mail & Guardian and on this website knows that particulates are a serious health risk.

But modern stoves typically emit 2 to 4 grams of particulates per hour, and some are closer to 1, that’s just 2% of the particulate pollution from a wood-burning open fireplace. And about a quarter of what a typical diesel car might produce. In addition, they retain 75 percent or more of the energy in the wood to heat the room, losing just a fraction to the flue. A free-standing stove unfortunately doesn’t suit my lounge, but the fireplace inserts are only a few percentage points less efficient and just as clean.

Perhaps most important, burning wood is widely considered to be almost carbon neutral, because a decaying dead tree would release carbon dioxide anyway, while a new tree growing in the place of the old one absorbs the greenhouse gas. Firewood from the urban forest is even closer to carbon neutral than most because it was going to be cut anyway and involves minimal transport.

Only two fireplace inserts fit my opening, but they seem like good units. I’m seriously considering the Scan DSA 3-5, which rates at 76 percent efficiency. I haven’t yet found particulate emissions data for this fireplace, but it seems similar to the DSA 4 which emits a very low 1.1 grams of particulates per hour. If I could choose among a wider range of wood stoves, I would look for one with the Swan eco-label. Among the brands in South Africa, Scan, Morsø, and Jötul all have stoves that meet the wide variety of environment criteria to earn the Swan logo. A list of Swan stoves can be found here.
These advanced, closed-combustion stoves are not cheap. Expect to pay at least R10 000, and up to R40 000 for a top-of-the-line wood burning stove. But the wood is cheap. Malcolm Sims of Cosy Heating has done calculations suggesting that gas now sells for R1.23 per kilowatt hour of energy, whereas wood is about 30 cents per kwh if burned in a 75 percent efficient stove-cheaper than electricity. (Cosy Heating sells both gas and wood heaters.) Comparing my inefficient Jetmaster with the Scan fireplace, I could heat with wood for one-tenth the price, though the Jetmaster offers greater control in adjusting the flame, which would mitigate that somewhat.

Sadly, Cosy Heating says that my Scan fireplace is out of stock because of the load-shedding rush. So for the next seven weeks we’ll be huddling next to the open gas fireplace when the lights go out, and thinking about how warm that chimney must be.

A warm, green towel, served medium-well

A friend of mine stopped by yesterday on his way home from shopping for a heated towel rail. He had been fretting for years at his wife’s extravagant use of the tumble dryer simply to warm and dry a single towel before bathing. He worries that tumble dryers use vast amounts of electricity. I used to have a similar affliction, until my tumble dryer broke down last year. I simply didn’t bother to repair it, and I have been a happy man ever since.

The towel rail my friend wants to buy, he told me, uses about as much electricity as a single light bulb, or 100 watts. Though my friend is a former maths teacher, I wasn’t convinced that he had done his calculations.

Heated towel rails are designed to run constantly; they generally don’t come with timers or thermostats, other than a safety shut-off to prevent overheating. If he runs this towel rail constantly for a year it will consume 876 kilowatt hours of electricity and add nearly a ton of carbon dioxide to the atmosphere. In my house, that would mean a 10 percent jump in total consumption most months. And at the rates just proposed by the Johannesburg municipality for the coming year, the towel rail would increase his annual electricity bill more than R350. If rates triple over the next several years, as predicted by some experts, the annual cost would approach R1000.

Tumble dryers use roughly 2000 to 3000 watts. That’s terrible. But presuming that his wife doesn’t leave the tumble dryer running all day to keep her towel warm and dry, it might use less electricity than the towel rail. Run a 2500 watt tumble drier for a 30 minutes a day and it will use less than half the electricity—and contribute half the carbon dioxide—of  a round-the-clock towel rail.

That’s still not good for the environment, however. The almost-environmentally-friendly solution is to have an electrician install the towel rail with a switch and a timer and then use it a few hours a day in the winter and turn it off entirely in the summer. The hundreds of rand you will save each year will easily pay for the timer. The problem with this solution is that it contributes to load-shedding because it will add to your electricity consumption at the exact morning and evening peak hours when Eskom has no spare capacity.

If you really can’t see a way to keep your spouse happy without warm towels—and I am very conscious that sometimes we must compromise to avoid marital misery—I suggest trying the microwave oven. WARNING: YOU CAN BURN YOUR SKIN OR EVEN START A FIRE IF YOU HEAT A TOWEL IN THE MICROWAVE FOR TOO LONG. I would not even attempt this in a microwave without a digital timer, and children should not be allowed to try this unsupervised. For my 750-watt microwave oven, 30 seconds warms a small towel nicely and 45 seconds heats a large bath-sheet towel to perfection. Thirty seconds at 750 watts is a mere 2 percent of the electricity used by a 100-watt towel rail in 3 hours. If you don’t have a doting lover on hand to run the warm towel from the kitchen, warm two towels for 30 seconds each and wrap one inside the other to keep warm while you bath or shower. Just because I’m opposed to global warming doesn’t mean that I don’t support wet-body warming.

My article on televisions and electricity consumption is now available on the Mail & Guardian website at this link. The previous post contains all of the practical advice that a television buyer could glean from the article, but the original text does provide more context. It also includes a salient comment by Professor Ernst Uken, head of the Energy Institute at the Cape Peninsula University of Technology.

Uken says households play a larger role in the South African power crisis than their overall consumption would suggest. The morning and evening spikes in power usage are caused by the domestic sector, he says, “and spikes are the reason for the power outages. The tail is wagging the dog.”

Perhaps you have heard of Moore’s Law. Named after the founder of Intel, Gordon Moore, it states that computing power of integrated circuits doubles every two years. In the latest issue of the Mail & Guardian, I have introduced what shall heretofore be known as Boroughs’s Law. Named after the founder of Greenerhouse, Don Boroughs, it states that for each additional ten inches in flat-panel television screen size, its electricity consumption approximately doubles.

I discovered this law by plotting the consumption of TVs sold in South Africa on a graph, and it’s the most important thing you need to know when buying a television. Because just to look at it, you might think that a 50 inch TV—manufacturers measure these things on the diagonal in inches—would use 20 percent more electricity than a 40 inch TV. You would be wrong.

Forty-inch TVs shouldn’t use more than 250 watts. (The worst ones use more.) Fifty-inch TVs typically use 500 watts, more than six 60-watt lamps. Boroughs’s Law works all the way through the range of television sizes available in South Africa, from 20 inches to 60 inches.

This tells you that the first thing to do is when buying a television is to convince your partner—or yourself—that you can get by with a TV one size smaller than the one you have been considering. A 32-inch LCD TV, which would have been considered large not many years ago, should use a reasonable 150 watts. That’s not much more than the average large CRT TV—the kind of TV we’ve all been using for the past few decades—and even less than the least efficient CRTs. (Cathode Ray Tubes.) Sony sells a 20-inch LCD which uses an amazing 60 watts. The incredible efficiency of LCD screens at small sizes—and only at small sizes—explains why they are the greenest choice for computer screens.

Once you have decided on a size, there is still a wide range of power consumption, even within the same brand of television. Thirty-two inch TVs, for example, vary in consumption from 132 watts to 380 watts. Televisions should come with big labels stating their consumption, and one day they will. In the meantime, there are only two ways of learning the wattage of a television: through the internet or checking the label on the back of the TV. If you are researching from home, try these websites:

www.philips.co.za
www.sony.co.za
www.samsung.co.za

Once you find a TV that interests you on the web page, click on “technical specifications,” or similar wording. The wattage is usually hidden near the bottom of the list.

You should be able to find a 32-inch TV using 140 watts, a 42-inch screen using 240 watts, or a 46-inch model using 270 watts. LCD TVs tend to use less electricity than plasma TVs. If you really feel that you must have a larger TV, the only models that use acceptable amounts of power are rear-projection TVs. Experts say that their picture quality is as good as flat-panels, they cost a lot less, and the Sony models use about 200 watts, all the way up to a 60-inch screen. They are bulkier, however, and will not be available for too much longer, as they are losing the battle for market share. This may lead to close-out bargains.

If you don’t want to sift through a hundred models, I suggest starting with the Philips brand, as they tend to be more energy efficient. I would avoid LG, as they tend to be more power-hungry and they often don’t state the wattage on the label at the rear of the TV. If you like Sony, and money isn’t much of an object, the European Imaging & Sound Association gave its most recent Green Television of the Year award to the Sony KDL-40D3000. That exact model isn’t available in South Africa, but its local equivalent is the 40-inch D Series Bravia model KLV-40D300A, which uses 180 watts.

Their voting panel looks at ease of recycling and other environmental issues in addition to electricity consumption, so this should be an all-around good choice if you need a big TV.

Or of course you could just stick with your existing CRT television. I checked my 2-year-old, 29-inch Philips CRT television, and it uses 73 watts. If you use an older TV, it is doubly important that you switch it off at the box, rather than using the remote to put it into stand-by. (This also reduces the chance of damage from a lightning strike.) Almost all new flat-panel TVs use one watt or less in stand-by, but older TVs draw enough power in stand-by that in a day you may use more electricity not watching TV than you do watching it.

The 35 degree solution

For years I’ve had to avoid my wife, for fear that she would again ask me how long she must wait before I will replace our leaky, ineffective dishwasher. This Indesit was so old that the last few repairs have required salvaging used spares. I had been procrastinating that decision even though I knew that it would reduce wasted water and electricity. My procrastination had nothing to do with a fondness for mopping the floor or scraping crud off the bottoms of teacups. I simply feared the amount of research that would go into finding an energy-efficient, water-conserving dishwasher that gets dishes clean. I am happy to report that my new Bosch SGS44E12EU (also called the SGS43E02EU) arrived today, and the investigation was not quite as painful as I had anticipated.

Not that I got everything that I wanted. My first goal was to find a dishwasher that could make use of the spare hot water my solar panels produce for nine months of the year. Alas, a Bosch technical representative explained to me that no domestic washer has hot and cold intakes, and the intake valve on a Bosch dishwasher could not tolerate a temperature above 40 degrees. This would require me fitting an expensive mixer valve to cool the water before it entered the machine. Besides, he explained that the way modern dishwashers work is to start with cold water and gradually raise the temperature. Use hot water in the first cycle, he warned, and you will bake the food onto the plates. I gave up on that track.

The next step was to compare water and electricity usage of various dishwashers. In Europe, Australia and many other markets, this is a simple task. Each appliance is labeled with a large sticker showing energy consumption, water consumption and an overall A-G rating. Dishwashers in Europe get three ratings: one for energy consumption, one for washing efficiency and one for drying efficiency. The Department of Minerals and Energy has long been promising South Africans a similar system, starting with refrigerators in May of 2005. Two and a half years later, the only appliances with an energy labels are a few imports with their European label intact.

Still, through the Internet, brochures and the Which? website, it was possible to get information from overseas efficiency ratings. Bosch’s South African website, for example, clearly displays the European ratings and consumption data for all of its dishwashers. (Curiously, they don’t display that information for their tumble driers, which, like the vast majority of these energy hogs, get Cs.) All of Bosch’s dishwashers get European As for energy consumption, which means that they use less than 1.06 kilowatt hour for a standard 50 degree wash. Not coincidentally then, many dishwashers, including all of the Bosch dishwashers sold in SA use exactly 1.05 kWh. The one I chose also uses a modest 17 litres of water for a standard wash. The top-of-the-line SGS 46 E 28 GB uses a mere 12 litres. But it costs R6399, a full R3000 more than mine, which is a lot of money to pay to save the equivalent of less than a flush of the toilet.

More important, the upper-range dishwashers have 45 degrees as their coolest setting. The economical dishwasher I chose goes down to 35 degrees. My sister-in-law uses a Bosch similar to mine and says that she never moves it from that coolest setting. She doesn’t rinse anything before putting it into the dishwasher, and even sticky porridge bowls come out clean. I haven’t succeeded in getting the data from Bosch on the electricity consumption of a 35 degree wash, but I did my own calculations. Since it uses 1,05 kWh for a 50 degree wash, and since heating 17 litres of water by 15 degrees should theoretically require 0,28 kWh, the 35 degree wash should use approximately 0,77 of a kWh.

A while ago, I checked the consumption of my old dishwasher at home, using the same, moderately precise methods I used to check electricity lost to chargers, transformers, appliances on standby and other vampires. It used 1.35 kWh on its lowest setting and guzzled 35 litres of water. Worse yet, because it cleaned so poorly, we used many more litres rinsing dishes. This is a purchase my gardener will appreciate. (Why? See here.)

My dishwasher only gets a C for drying efficiency, but that’s because it doesn’t have the electricity-wasting drying feature. It should get an A+ for leaving that off.

If you want to read a good overview of dishwashing written with a sense of humour, check out the Appliance Advisor’s guide to green dishwashing. By the time you are finished reading it, you will be convinced never to rinse your dishes again before putting them in the machine.

But do you even need a dishwashing machine? Advertisements for dishwashers often claim that they use far less water and energy than hand washing. I’m not so sure. Washing carefully, with 5 liters of solar-heated rinse water in one sink and 10 litres of solar-heated soapy water in another, I could beat any dishwasher on energy consumption. But my new dishwasher is a big step in the right direction. And it’s a lot better for my marriage.

Three aging appliances in my kitchen have been declared beyond repair, which has led me to undertake a lot of research on appliances. A good starting point I have found is Which?, the British non-profit magazine and website that thoroughly tests and reviews consumer products. I will report on my research on dishwashers, etc., when I have completed it. In the meantime, I stumbled upon this page in on the Which? website that has interesting, straightforward, and surprising information on television electricity consumption.

I had always assumed that LCD televisions use far less power than standard CRT (Cathode Ray Tube) televisions, since this is the case with computer monitors, as I reported here in my post on saving electricity in the office.

Which?, however reports that after testing dozens of TVs, it found that a 32-inch CRT TVs use 50-100 watts, similar sized LCDs use 100-200 watts, and 42-inch Plasma TVs (they aren’t made in the 32-inch size) consume 200-300 watts. That’s up to 6 times more than a CRT only 10 inches smaller.

Though I believe the Which? does very thorough and unbiased research, I do think that the full story is slightly more complicated. A revealing chart produced by the Australian government when researching electricity consumption by TVs shows that in the smaller sizes (below 40 cm) , LCD TVs are more efficient on average. This would explain why they are the greener choice for a PC monitor. But CRT TVs don’t experience as great a leap in consumption as they get larger. LCD and Plasma TVs use a lot more electricity with each step up in size. Beyond 60 cm, most CRTs are somewhat more economical, though there is enough variation between models that it is possible to find a large LCD that outperforms a same-size CRT at the plug.

As for Plasma TVs, they are simply energy hogs. The larger ones can draw 500 watts or more. Some guides to televisions will divide the consumption by the size of the TV, which makes plasma televisions look a little better. But I think this is beside the point. One of the most important decisions a television buyer must make is the size, and it is important to know that making do with a smaller television is much better for the environment. If you already own a plasma TV, you can reduce its power usage by turning down the brightness. (Dim the room lights at the same time and you’ll save again.)

And, as I explained in this post, when you’re finished watching, take the consumption all the way down to zero. Don’t put it into standby with the remote; turn it off at the television itself.