Letters: July/August 2013
Fixing Problems, Saving Lives
I enjoyed your article “Air Sealing and the CAZ” in the Mar/Apr issue (p. 10).
I started in the HVACR business in 1987. My main focus was service. When I did installs and removed a furnace from the common vent with the water heater, I would recalculate the vent size according to the venting tables and usually run a chimney liner inside the common vent or chimney to serve the water heater by itself. This solved many spillage problems.
PG&E Energy Training Center
Author A. Tamasin Sterner replies:
Thanks. That is a common fix around here, too. Even with the liner, we’ve seen many water heaters spill because of suction on the CAZ from the stack effect and unsealed attic floors. Scary.
Comparing Apples to Apples
The claims of the editorial (“Heating and Cooling No Longer Majority of U.S. Home Energy Use,” May/June ’13, p. 2) are based on site energy consumption, which is not a very useful way of talking about energy use. It tells us how much energy is used on site (which is essentially meaningless), without making any distinction between electricity, gas, and other fuels, even though there are great differences among them in price, natural resource depletion (primary energy factor), and global warming potential. In other words, it groups apples and oranges together in an unacceptably inaccurate way. For example, if our concern is energy security, we should be looking at primary energy use. When I do, I see that primary energy (PE) for heating has dropped by about a quad (~20%), cooling has risen by about half a quad (~20%), domestic hot water has stayed the same, and appliances/electronics/lighting have gone up by a whopping 4 quads (~50%). As a result of this one category, total primary energy use in the residential sector has risen by about 20%. As home energy use shifts from combustion fuel towards electricity, continuing to express that use in terms of site energy will mask the severity and source of a real trend in increased energy use in homes.
Author and Senior Executive Editor Alan Meier replies:
The reader is completely correct about the misleading nature of the Energy Information Administration’s (EIA) pie chart. The situation is perhaps more ironic than he imagined. When the data are recalculated and displayed in terms of primary (rather than site) energy, one discovers that heating and cooling was already less than half of residential energy consumption in 1993! Thus, EIA’s “news” was actually 20 years behind the event!