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.

Using wood in such an efficient stove can be even better for the planet. In fact, some scientists argue that if a tree is planted for each one harvested, fuelwood has virtually no net impact on atmospheric carbon dioxide, as the new tree absorbs as much CO2 as the old one releases. South Africa has too few hardwood trees for very many people to adopt this option, however. I also wondered where I would fit splitting wood and stacking kindling into a busy homelife with a family of six. I still hoped for a solution as simple as it was clean.

I knew that my wife had her heart set on a gas Jetmaster to fill the gaping hole where our oil heater had been. (Oil-burning heaters are no longer sold in South Africa.) Gas has a well-founded reputation as the cleanest of fossil fuels, releasing one-third less carbon dioxide than coal for the same amount of energy. The minister of minerals and energy wants to see gas consumption quintuple in South Africa as part of the nation’s commitment to address global warming. Surely a gas fireplace would prove to be the formula for marital bliss.

Alas, the first Jetmaster salesman I consulted quickly dashed any hope that I had found a panacea. “At least half of the heat goes up the chimney,” he acknowledged as we basked in front of the glowing “coals” and dancing flames. The words “gas” and “efficient” are most fully united, it turns out, in gas heaters that have no flue, exhausting all of their heat into the room.

I had seen the rollabout heaters with their 9 kg LP gas bottles bulging out the back. These heaters, selling for around R1 000, met my requirements of environmental and financial efficiency. They have become increasingly popular, with 40,000 purchased in South Africa last year. Yet even I had to admit that they looked better suited to the garage than the living room. And I felt a vague unease about changing gas bottles inside the house and keeping them within reach of little hands.

Then the salesman pointed to something white on the floor that barely looked like a heater. Svelte and curvilinear, this unassuming package of Japanese electronics–smaller than a magazine rack—displayed no flame, no glow. But it packed enough gas heat to leave the fireplace I had just examined shivering in its wake. The Rinnai 329 heater, one of the smaller flueless heaters in the company’s large line, also boasted 5.7 stars on the Australian Gas Association’s six-star rating of energy efficiency. And instead of toting a 9 kg gas bottle, it was designed to hook up to a gas line leading to town gas or a 48 kg bottle of LPG stored outside the house.

The solution became clear: a Jetmaster 700 Convector for her and a Rinnai 329 for me. The added expense—the Rinnai costs about R4 500 in addition the Jetmaster’s R5 700—would be covered in time by the gas savings from not being restricted to one, less-miserly heater. In practice, the heaters have worked according to plan. The flueless Rinnai is our guilt-free, day-to-day heater, popular with the kids for quick morning warm-ups. We opt for cozy flames in the fireplace when guests are due to arrive.

In my own tests, the heaters have also lived up to their promise. The flueless heater consumes about a quarter of the gas used by the convector to create the same increase in room temperature, releasing one quarter of the pollution in the process. When I dragged our oil-filled radiator out of the bedroom to duel with the gas appliances, it took three times as long as either gas heater to warm our lounge. (Electric heaters are limited to 2400 watts in order to connect to ordinary plug points.) It fared even worse against the Rinnai in the carbon dioxide stakes, contributing about nine times as much CO2 to the atmosphere.

No matter how clean gas may burn, venting its emissions inside a house does raise questions about indoor air pollution, especially carbon monoxide. All flueless heater makers warn that rooms must have access to fresh air. If we have run the flueless heater for more than a couple of hours, we turn it off, switching to the fireplace if necessary to keep warm. But after spending a week with an industrial carbon monoxide meter, most of my concerns have been put to rest. Not once did the instrument register 1 part per million in my lounge, even after the heater ran on high for three hours. Clearly our drafty windows and ventilation blocks provide adequate air to the room.

The only way I was able to create measurable carbon monoxide was by breaking all of the rules. I closed myself into our tiny TV room—where we have a second gas point—and ran the heater on high until the temperature had risen a stifling eight degrees and the CO level hit 11 ppm. I would not be comfortable letting my family breathe such levels on a regular basis, but it is still less than a quarter of the CO levels that the strict U.S. Dept. of Labour allows workers to breathe for an entire day. When I repeated the experiment with the TV-room door open, the meter read 0 ppm.

A few parts per million of carbon monoxide would seem like a breath of fresh air to the 4.4 million South Africa households choking on the fumes from burning wood, dung, paraffin and coal in crude braziers. For them, the first priority must be indoor air pollution. Philip Lloyd of the University of Cape Town’s Energy Research Institute estimates that 16,000 South Africans die prematurely each year just from breathing inside their homes. “Go inside an informal shack in mid-winter,” he suggests, “then you’ll find out what passive smoking is really all about.” When Lloyd accompanied a U.S. Department of Energy pollution expert on a tour of Cape shantytowns, the danger alarm on the American’s carbon monoxide detector was ringing almost constantly. For the poor and poorly ventilated, Lloyd recommends electric heat, where possible.

For those South Africans who want plug-in heat, but need guidance in choosing among the options, four Tukkies have already done the homework for them. These students were enlisted by Prof. Johan Delport, former head of the University of Pretoria’s Centre for New Electricity Studies, as guinea pigs in a heating experiment. Delport knew that all electric heaters convert electrons into heat more-or-less equally efficiently. “Resistive load is resistive load,” as he says. The difference is in how people experience that heat. So Delport used students, instead of thermometers, to measure “kilowatts per comfort level.”

The popular electric oil-filled radiators, Delport learned, mostly bypassed the students to warm up the ceiling. Glowing infrared heaters, such as the common quartz two-bar heaters, warmed the students quickly and cheaply, but only if they stayed near the heater. Such radiant heaters do little to warm the air itself. The best performance in warming both the students and the space without wasting electricity came from 2000-watt fan heaters with thermostats.

Delport says that the increasingly popular underfloor systems are particularly costly to power. Even David Wantling, who sells underfloor heating, as well as gas, coal and wood heaters, agrees that claims of efficiency by underfloor heating companies are exaggerated. “It’s a bit like companies claiming, ‘my V8 engine is 30 percent cheaper to run than my competitor’s,’ but the bottom line is: All V8 engines are heavy on fuel consumption,” explains the owner of Jay MacDonald & Sons, Cape Town. Delport, for all his expertise in electric heating, recommends gas heat for all but the smallest houses, since a couple of electric heaters, in conjunction with a geyser and a stove, will frequently overload circuit breakers.

So which does Delport use in his own house? None of the above. He keeps his Pretoria home warm with a well-insulated ceiling and hot air that he blows down from his attic with a system he patched together himself. He claims to get 4 600 watts of free heat with nothing more than a 40 watt fan. Now all I have to do is convince my wife that what she really wants is a hole in the ceiling.

Postscript: The main change since I wrote the article is that Rinnai has discontinued my 323 model. The most similar Rinnai heater today is the Enduro 13, which Cosy Heating in Randburg sells for R8284, though you can buy it from many other heating and gas specialists.

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.