Tuesday, June 30, 2009

A True of False Quiz

It's easy. What's amazing is how many people fail it. [More]
Posted by David Codrea at 6/30/2009 12:33:00 PM

6 comments:

TJP said...

Like the post, except for this part:

"a) Given that most of our homes require heat for the majority of the year, and that incandescent light bubs are "inefficient" because most of the electricity is "lost" in the form of heat rather than lighting, conversion to fluorescent lighting will require additional output from the home's heating system for at least part of the year (unless you live in Florida or Hawaii...). This transfer of heating cost must be considered when determining the overall "savings", as must the additional costs of proper disposal of the fluorescent bulbs due to their mercury content."

Yeah, I've heard that one before. The truth is that residential heating is ballpark engineering, because everyone's home is different. Since most people have been buying 2,500+ square-foot homes, a standard furnace package includes a burner designed to heat a home this size. Heat output is controlled by the cycle and adjusted by swapping nozzles, not by flipping light switches. Since furnaces have a required minimum efficiency, the furnace will kick on and run for the specified amount of time, because the fuel burns much more efficiently in a hot burn box with plenty of oxygen. Your 60 watt bulbs put out about 190 BTUs--your furnace as delivered will likely be fitted with a nozzle that will make it run around 90,000 BTU. Unless you have 500 incandescent lights on a timer, you're really not going to see any difference in fuel costs over a heating season.

Disposal cost is nearly a non-issue because, at least in my experience, a CFL lasts 8 years while a filament bulb goes 6-12 months.

I suspect that the author's purpose was to take a stab at CFL mandates, with which I do not agree, but I do prefer a more easily defended argument. The biggest difference in energy savings will come from finding a way to to severely reduce the consumption of the Big Three: fridge, stove and dryer. Switching to CFL bulbs for the cost savings is like parking your car six feet further back from the garage to save on gas. The best answer to conspicuous consumption is market pricing.

6/30/2009 1:45 PM
Axeanda45 said...

TJP totally forgot about electric furnaces, and the FACT that most furnaces are thermostat controlled.

6/30/2009 4:40 PM
TJP said...

My entire comment is based on the premise that furnaces are controlled by conventional thermostats. Or does yours check which lights are on and then find the median temperature of the entire house before signaling the furnace?

6/30/2009 7:15 PM
Anonymous said...

ITJP -
I suggest you buy a few of the Chinese-made CFLs (which are rapidly becoming all that are available) before you talk about their 8 year life span. I have, and about 50% of them are good for about three months of on-off cycling. Granted if you turn one on and leave it on it will last a long time - as long as it isn't mounted upside down). But then Edison's first successful incandescent was still burning 50 or 60 years later.

Oh, and did you ever try to light a cigarette off a CFL, heh?

6/30/2009 8:50 PM
straightarrow said...

Anon, I will be lighting them from a kerosene lamp if the Cap and Trade goes through.

7/01/2009 1:36 AM
TJP said...

Actually, I'm still using some decade-old GE Chinese-made CFLs. Ya pays yer money, ya takes yer chances.

If you'll excuse my disappointment, I figured that in the face of the largest "social economics" power grab in the history of this country, I was expecting our side to argue some points about paleoclimatology, absorption bands, principal component analysis or measurement irregularities, (and there are more than a few.) I didn't expect that the bulk of criticism would be directed toward a 99-year-old technology which, up until recently, no one questioned.

7/01/2009 11:23 AM

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