In order to save money on utility bills it is imperative to know what you are spending, why and where.
Most people know what electric service, gas, and water are costing each month and that fuel prices are projected to rise dramatically before winter sets in. (The one good result of the current financial mess is that its impact on the price of oil will mean that increases will not be as dramatic as previously thought, however, the current state of the pocketbook in many homes means that every wasted penny means pain.)
Homeowners and renters may not be quite as aware of why and where their utility dollar is being spent so an energy audit may be in order. A superficial audit can be a do-it-yourself project and there are a lot of tools available to help in this task and we will cover some of these another time. But to get a true measure of where energy and money are both being wasted, a professional audit is the way to go.
State and local government energy offices often maintain lists of companies and individuals who conduct these offices and local electric and gas companies may also have lists of reputable contractors but they also may offer the service, and sometimes at a reduced rate, to their customers. Contact information can also be found in the Yellow Pages under various "energy" headings or on-line (search "home energy audits" or "residential energy audits.")
Before hiring an auditor, you should do thorough due diligence as you would before engaging any contractor. In this case ask for and check references from previous customers; contact the Better Business Bureau for any record of unresolved complains, and ask about price and if the auditor offers a blower door test and a thermographic scan.
A competent auditor will do an examination of every room in the house and the basement and attic if relevant and possible. He will also examine previous energy bills, ideally for a full year. If you have thrown these out, call your utility company for a printout. The auditor will also ask questions about patterns of energy usage in the home. Is anyone home during the day? How many people and of what ages live in the home? Where is the thermostat typically set both winter and summer? Does the family tend to congregate in one or two rooms or do they spread out all over the house, using multiple televisions and electronic devices?
As the energy auditor surveys your home, walk along with him. He should be willing to answer questions and explain what he is doing.
Typically the auditor will start outside, looking at the dimensions of the house, exterior sheathing and roofing material, visible penetration of the building by flues, vents, and fans; and the number, size, condition, and age of the windows and doors.
Inside he will measure the temperature and humidity and attempt to get as much information as possible about existing insulation, and wall framing and will test electrical appliances and outlets.
The major systems he should evaluate include ducts (insulation and leakage), water heaters, and HVAC systems (efficiency and air balance.) He will also look at lighting use (a 100 watt bulb in a closet or a continuously burning light in an attic or on a porch use more power than one might think.)
As mentioned above, two tests that are needed are the blower door test and a thermographic scan.
In the blower door test the auditor uses a powerful fan mounted in an adjustable and flexible temporary door. The door is placed in the frame of an exterior door; it evacuates air out of the house, lowering the pressure inside. Air from outside then rushes in through cracks and other openings to correct the imbalance. The auditor uses smoke or some other visible vapor to find these leaks. There are two types of blower doors - calibrated and uncalibrated. The former has several devices that measure the amount of air pulled out of the house, allowing the auditor to estimate the effectiveness of any air-sealing job. An uncalibrated door can only locate leaks; it cannot determine the tightness of the building.
Thermographic scans use infrared still cameras and video which see light as colors indicating temperature. Pictures are taken of the building skin with white being a sign of heat, black of cooler areas. The images indicate spots where insulation is needed. Scanning can be done at the auditor's discretion either inside or outside usually depending on weather conditions; indoor scans are more common. Thermography is usually done in conjunction with a blower door test as the door increases air leaking through cracks and other defects. (Note to potential do-it-yourselfers; infrared film in a conventional camera will not detect heat loss to any useful extent.)
The auditors report will include, along with an assessment of the energy health of the home, suggestions for retrofits and improvements and sometimes costs for these improvements and estimated time for recovery of the expense.
Prices for professional audits are in the range of $250 to $500 and some companies will offer a discount on necessary improvements. We found one utility in the Dakotas that offered a basic audit for $25 and a more comprehensive audit for $100 (including a door blower test.) The utility and others include free weatherization supplies with their audits including such things as heating blankets for hot water heaters, lo-flow aerators for faucets, weather stripping, door sweeps, and spray cans of expanding foam insulation depending on what the inspector judges as helpful. Utility companies offering low-cost audits seem to be more prevalent in colder areas of the country.