January 20, 1995

Save Energy While Still Preserving History

Amy Michelson Washington State Energy Office
 

You’ve finally found the perfect Victorian house. Just the right amount of gingerbread and that great turret, a definite candidate for the historic register.

Energy efficiency was probably the last thing on your list of “must haves,” right? Everybody knows old houses are a little drafty.

So, how come nobody mentioned drafty could really be a howling wind sucking all your heat out the window frames? Or hinted that the quaint old furnace just might give you a heating bill equal to the national debt?

Don’t panic yet. There are some simple things home owners can do to both conserve energy and preserve historic integrity.

Though true of most existing homes, some problems are more likely to occur in a historic house, due to past construction techniques used. Some of these are air leakage, inadequate insulation, faulty thermostats, an out-of-date furnace and leaky duct work.

As with most home improvement projects, it’s best to start with the simplest measures first. Caulking and weather-stripping are two most homeowners can easily handle.

Caulking can help with one of the biggest problems in older homes, air leaks. These leaks tend to occur around hollow walls, closets, plumbing cutouts, electrical service panels or even behind kitchen cabinets. Leaks in the ceiling should be your first priority.

Window frames are another notorious contributor to air leakage. One simple test you can perform yourself is to place a fan in a partially open window so the air blows out of the house. Seal around the fan with foam rubber or rags and close all other doors and windows.

Then light an incense stick and walk around the most likely-to-be-leak places. By watching the smoke, you should be a fairly good idea of where currents are sucking air (and your heating dollars) out.

Another method involves making a draft gauge. Tape a plastic sandwich bag or a piece of light tissue paper to a coat hanger. Hold the “gauge” by the handle of the hanger close to the edge of the frame. Any incoming breeze from gaps in the caulking will move the plastic or paper. (Your hand can feel drafts that this gauge may not detect.)

Concentrate your caulking efforts there. Use weather-stripping products around larger gaps like door frames, windows, electrical outlets, attic vents and plumbing penetrations through the walls or ceiling.

There are two important things to remember when undertaking air sealing.

First, you should always be sure that adequate ventilation is available. You need to ensure that combustion appliances such as furnaces, water heaters, fireplaces or wood stoves have adequate air. They need to have sufficient air to both operate efficiently and pull gases such as carbon monoxide up flues or chimney.

If you have any doubts, have your home tested by a registered heating contractor or air quality expert.

Second, be sure to do all your air sealing before adding any insulation, while the areas are still accessible.

Inadequate insulation is often a drawback of the historic home. You’ve probably heard stories of homeowners finding 50-year-old newspapers used as insulation.

Modern insulation might not be such fun to read, but it will improve your heating efficiency much more effectively. Generally, you’ll get the most savings from your insulation dollar by concentrating on attics, floors or exterior walls and cavities that separate heated from unheated spaces.

Aim for at least 6 inches of insulation in heated basements walls and exterior walls. Floors over an unheated space such as a crawlspace or unheated basement should be insulated.

Ideally the insulation between floor joists should be R-30. Attics should have a slightly higher level of insulation. Look for products labeled R-38.

The R refers to the product’s R-value, a rating of its ability to resist heat flow; the higher the R-value, the greater the resistance.

Since historic commissions are often most concerned with the exterior integrity of homes, try to use interior-based insulating techniques.

You might not have thought about it, but thermostats, like any other mechanical equipment, can wear out over time. Most people set a thermostat based on comfort not temperature.

If you are curious about the relative accuracy of your thermostat, place a thermometer in the vicinity of your thermostat. Both should read about the same temperature, plus or minus a few degrees. If you have a major difference between the two, it might be time to replace your thermostat.

When shopping for a new one, check to be sure it will be compatible with your old heating system. Check the installation manual and wiring of the old and new models to see which is the best match for your needs. Look for thermostats featuring a programmable automatic setback.

Many historic homes come equipped with prehistoric heating equipment - older oil burners, or coal furnaces that have been converted to natural gas or oil. Older furnaces, called “gravity air furnaces,” used natural convection heating principles to heat your home rather than the more common forced-air setups. Hot air rises, and thus eventually, your bedroom got warm. Gravity air furnaces required large duct work to move the warm air upward.

Converting an older furnace did not always mean converting the ductwork to a more appropriate size. And ductwork in older homes was often never sealed or can be prone to leaks where duct tape has deteriorated or pieces have come loose within crawlspaces. Consequently, you might be losing a great deal of heat.

Duct leaks can also cause heating equipment to backdraft, bringing dangerous combustion byproducts into the home.

Because of combustion safety concerns, the actual duct sealing should be done by a professional. Some symptoms of duct failure are discomfort despite a high thermostat setting, high utility bills and foreign matter or odors coming out of heating registers.

To assure that the heating equipment is venting safely, periodic inspection of the heat exchanger and chimney is also recommended. And depending on your resources, you might want to consider converting to higher efficiency heating equipment.

For more information on energy and the historic house, you might want to check at your local library for the following publications:

“This Old House Heating, Ventilation, and Air Condition: A Guide to the Invisible Comforts of Your Home” by Richard Trethewey (Little, Brown and Company).

A House For All Seasons: Rousing Home Renovations and Heating the Historical House (PBS Video, 1988).

The Old House Journal also covers similar topics. Check with your local library for locating appropriate articles.

You may also want to check out the Corbin Art Center’s home restoration class series. The first class in the series will be “Restoration Techniques for the Historic Home,” an eight-week class to be held on Wednesdays from 7 to 9 p.m. beginning next Wednesday. This class will provide practical information on products, research methods and restoration techniques.

For more information on this class and others in the restoration series, contact the Corbin Art Center at 625-6677.

Ellen Levesque contributed to the writing of this column.

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