Gas/Electric Debate Not Objective

First, such a comparison would be a total misuse of the rating system. The guidelines stay fuel neutral by scoring a home compared to a reference home using the same type of appliances. Second, even if comparisons of differently fueled appliances were valid, the outcome would not be as described in the article. The guidelines require that the reference electric-heated home use a North American Energy Conservation Act (NAECA) minimum-efficiency heat pump as the reference space conditioning system. Therefore, replacing the gas furnace and water heater with electric counterparts (an electric-resistance furnace and water heater) in a home just meeting the gas reference home criteria (score = 80) would require that the home be compared to the electric reference home. This would significantly lower the score of the home below the reference home score.

The methodology described in your article, which was developed at Florida Solar Energy Center (FSEC), incorrectly normalizes the point score to "account for the differences in potential for improvements" in space conditioning and water-heating equipment. Even assuming that FSEC has accurately captured the full range of efficiencies for commercially available equipment in the development of their methodology, this effectively means that the FSEC methodology increases scores for homes with fossil fueled equipment because this equipment has less efficiency improvement potential than electric equipment. The result is that homes with fossil fueled equipment with efficiencies above that of the reference home will get higher scores under the FSEC method than under the HERS Council method. Scores for homes with electric equipment will essentially remain the same with the FSEC method as with the HERS Council method. Relaxing the scoring criteria for homes using the fuel with the largest market share (gas) does not seem to be an effective way to increase national energy efficiency, encourage new technologies, or promote the use of home ratings.

Harold L. Crowder Jr., AIA, CEM
Timothy A. Bernadowski Sr., PE, CEM
Conservation & Customer Technology Division
Virginia Power Company
Glen Allen, Virginia

Home Energy responds:

On September 19, 1999 the board of directors of the National Association of State Energy Officials (NASEO) unanimously voted to adopt the method of normalization for scoring that FSEC developed.

A house actually could improve its HERS rating merely by replacing the gas furnace and water heater with electric counterparts. It is true that, if the equipment is switched at the minimum-efficiency standard, there is no impact on HERS score. However, if the equipment is switched at the best available market equipment level, there would be a substantial HERS score advantage to switching from gas to electric. The new FSEC method removes the advantage at these high-efficiency levels, but it does not affect HERS scores in any way at the national minimum-standard efficiencies.

Furthermore, although it may be inappropriate--according to the HERS Council guidelines--to compare homes across fuel types, it is human nature to do so, and this does and will continue to occur.

Regarding the guidelines approach: The example you provide is very misleading. In accordance with any version of the HERS Technical Guidelines, whether used by the HERS Council, DOE, or NASEO, the electric counterpart to a gas-fired heating system is NOT an electric-resistance furnace; it is a heat pump with HSPF of 6.8.

The main opponents to change are the electric utilities. Examination of the 150 or so public comments that were received regarding NASEO's recent decision supports this observation. These comments may be viewed on the Internet at www.natresnet.org/techguide/comments.htm.

COSTCO Replies

Thank you for providing us with the opportunity to respond to your recent editorial regarding the energy usage of our appliance line, Kirkland Signature by Whirlpool Corporation ("My Discouraging Visit to Costco," Nov/Dec '99, p. 2). According to Whirlpool, in every case, the models we offer rate above the standards established by the federal government for each product category. You mentioned that the models we sell are "pinned to the highest edge of the scale--or even off the scale." The energy scale you referred to is derived from all the models from all the manufacturers that are on the market. Therefore, it is impossible to be off the scale, as a new higher (or lower) rating would then redefine the parameters of the scale.

While we are sensitive to the energy consumption levels and environmental factors for all of the products we sell, due to our limited assortment we are unable to offer all things to all people. We have chosen to offer the products with the most highly demanded features, with energy usage ratings that are comparable with the majority of similar products on the market. In the refrigerator category, for example, we offer models with built-in icemakers, a feature that is not the most energy efficient, but one that consumers demand.

The lower end of the EnergyGuide range is set by "high-efficiency" models that tend to cost at least $200 more than regular models. For dishwashers, it is natural that our full-sized units do have a higher consumption than the smaller-sized units that occupy the lower energy usage part of the scale. For washers and dryers, we fall slightly higher than midway on the EnergyGuide scale. Clearly, the $1,000 Maytag washer model that you referred to is unlikely to pay for itself in energy savings when compared to the fully featured, super-capacity washer that we sell for well under $400.

We will continue to offer the highest energy efficient models that provide the features and benefits that our members want.

Bill Prescott
Costco Wholesale
Issaquah, Washington

Home Energy's executive editor, Alan Meier, replies:

I stand by my observation that most of Costco's appliances are pinned to the maximum energy use of appliances in that category. I invite readers to visit Costco or Home Depot and confirm my impression. Costco errs regarding the impossibility of models having efficiencies worse (or better) than the range shown on the label. The Federal Trade Commission (FTC) updates the range only every few years, so a new efficient or inefficient model may fall outside the published range. The distance outside the range is usually small (but the confusion it causes is large).

Costco argues that the comparison is unfair because it sells models with special features demanded by its customers that consume more energy. In fact, the FTC prepares different labels for each major size and category of appliance. So, for example, large refrigerators with through-the-door icemakers are compared only against other through-the-door models in the same size range. Costco appliances are therefore the least efficient among similar appliances in that size and with those features.

I am not suggesting that Costco sell the most efficient appliances available, because the additional cost is not always justified by the energy savings. But I think everybody can win if Costco sells slightly more efficient ones. Costco can sell them for a small premium (probably under $50), and Costco's customers will recoup that premium through reduced utility bills in only a few years. Furthermore, Whirlpool--which makes some very efficient appliances--will be eager to provide them if asked.

Two More Tools for Diagnostics

Thank you for the helpful article about finding the source of moisture near a chimney ("Solving a Chimney Moisture Problem," Sept/Oct '99, p. 40). My experience has taught me that two diagnostic tools in addition to those mentioned are essential for dealing with these problems.

First, I install a permanent stack gas thermometer on every combustion appliance I work on. As moisture is commonly believed to condense at 212°F, the thermometer will show how close to condensing the exhaust gas is. The lower limits depend on many, many factors, but I expect trouble for exhaust temperatures below about 350°F for oil and 400°F for natural gas (natural gas contains more hydrogen, and thus more moisture is present in the exhaust gas) relevant for condensation in the stack after the draft control or hood.

The other tool I use is a work light with a 100-ft extension cord and a rough service light bulb. I shut the boiler off, then lower the light down the chimney and have a look. A flashlight is useless during the day, and I'm not climbing up there at night. The light twirls on the cord on its way down, giving you a complete view of everything.

If all the obvious checks out, I look for a potential water leak in the boiler that would add large amounts of moisture to the situation.

Henry Gifford
Gifford Fuel SavingIncorporated
New York, New York

Technical Editor Steve Greenberg responds:

Actually, water boils at 212°F at normal atmospheric pressure. Condensation happens at and below the dew point temperature, which depends on the amount of water vapor in the mix of gases in the flue. Typically the flue gas temperature must drop below about 150°F to get significant condensation in the flue, though temperatures over 250°F may be needed to prevent condensation of vapor from high-sulfur fuels, especially at low rates of excess combustion and dilution air. The water vapor distinction between flue gases in gas and oil may be outweighed by the difference in sulfur content (natural gas is normally very low in sulfur, while oil contains significantly more).

By the way, how long do you let the stack cool before lowering in a power cord with plastic insulation?

Healthy Home Needs Low Humidity

In a recent issue of your magazine, the Field Notes article was about a Virginia builder marketing a "healthy house" (see "Virginia Builder Reaps Success with Healthy Houses," July/Aug, '99, p. 43). I was interested to read that "air quality is tightly controlled" and that families who buy these homes are provided with a healthy living environment. The special steps taken to bring this about are impressive, but I'm disappointed to see no mention of a humidity control system.

On page 10 of the booklet Indoor Air Pollution: An Introduction for Health Professionals (published by the American Lung Association, the American Medical Association, the U.S. Environmental Protection Agency, and the U.S. Consumer Products Safety Commission), there are specific recommendations for ventilation and keeping relative humidity (RH) below 50%. In homes not kept below 50% RH, problems with mold and dust mites can develop.

The mechanical ventilation system discussed in the article can be a double-edged sword. Is it ever 70°F and raining in Virginia? Under this condition, every 100 CFM of outdoor air brings in 70 lb of water in a 24-hour period! The house becomes a ripe environment for the growth of mold and dust mites. If the air conditioner is the only method of dehumidification, it's no help without a reheat system (and if there is a reheat system, then there goes the heating and cooling budget!).

In short, a home that does not keep RH constantly below 50% can't have true indoor air quality. And yes--I'll admit it--my company manufactures a whole-house dehumidifier that is the most cost-effective way to provide this environment.

Bernie Mittelstaedt
Therma-Stor Products
Madison, Wisconsin

The builder, Jay Epstein, has declined to respond to this letter.

Home Energy can be reached at: contact@homeenergy.org
Home Energy magazine -- Please read our Copyright Notice