People today are more conscious than ever about the costs of energy, which have risen dramatically since 1973, due to the oil embargo. The prospect of continuing increases in energy costs has made many homeowners and prospective buyers take a very critical look at energy costs. Haphazard, hit-and-miss tactics for conserving energy are not effective in significantly reducing energy costs. While some savings may be realized, many things that can provide great savings are overlooked altogether.
Any energy-related project should be justified by comfort and economic benefit. If the amount of money spent will be returned to you in approximately 7 years or less, that is an improvement that should be considered. If it will take much longer, it is probably not economically beneficial. For example, if an attic does not have any insulation and you know that you can save 60% to 70% of the losses through the attic/ceiling by installing 9 inches to 12 inches of insulation, you should evaluate the cost versus payback.
In a house with a standard fossil fuel heater and a fuel cost of $1000 to heat the house for one year, the losses through the ceiling (assuming that there is no insulation) would be approximately $200 to $250. If it costs $1.20 per square foot (SF) to insulate a 1000 SF attic, the total cost will be $1,200. This will be about a 5 to 6 year payback. If the homeowner insulates the attic, and does a good job, it will cost him about $300 for the insulation. This would yield a payback in less than 2 years.
Insulating the walls is much different. If it costs $1.20 per SF to insulate the walls, plus possibly some cosmetic repairs, and the house has 3,500 SF of wall area, the cost would be approximately $4,200. If the savings are $200 to $250, the payback will be about 20 years. This would not be beneficial. A simplified breakdown of where the $1000.00 fuel cost goes is as follow:
- Approximately 1/3 goes up the chimney to carry moisture and unburned gases and hydrocarbons: $333
- Approximately 1/3 of the remaining goes straight up through the house: $222
- Approximately 1/3 goes through the walls: $222
- Approximately 1/3 is lost to normal entry and exit and at the windows and doors: $222
- There are other considerations, such as air infiltration, relative humidity, and occupants of the property. One adult adds approximately 50 BTUs per hour to the living space.
Windows and Doors
- Good quality, tightly sealed windows and doors greatly aid in the comfort enjoyed by the occupants of a structure and likewise reduce the energy costs associated with that comfort.
- Insulating windows, double and triple glazed, are very energy efficient if they are high quality and are well maintained. The greater the space between panes, the more efficiency they offer; 1/2 inch spacing between panes is becoming the norm. When inspecting insulated glass windows, look for signs of failed seals, (i.e. condensation stains that may barely be visible and whitish stains that obscure visibility); if such is noted, the entire window unit should be replaced to re-establish the effectiveness and purpose of the window. Thermal pane windows lower heat conduction by approximately 60% over single pane windows.
- Storm windows are recommended for installation over all windows in the structure, including the basement. Storm windows are typically made of aluminum and can be made for just about any size window. Storm windows should fit tightly and be caulked/sealed, except for weep holes at the bottoms, which should be left open to allow rainwater and condensation to drain. They also help to reduce the amount of condensation that might develop, because the temperatures on each side of the glass will be closer together. Obviously, to serve their intended purpose, the sashes on storm windows should be kept closed. Storm windows over single pane windows can reduce heat loss by approximately 40%-60%.
- Windows should have good weatherstripping and the locking mechanisms properly adjusted so that the sashes create a good seal with each other and the frames. Many types of weatherstripping are now available, but one of the easiest to use is rope caulking applied around the inside of the sash and window stops. However, the windows cannot be raised or lowered unless the caulking is removed. Wood and vinyl windows are reasonably weather-tight, especially the better quality windows. Aluminum windows are typically lower end, or inexpensive, and will be colder than wood or vinyl.
- Doors should be properly weatherstripped at the side jambs and the head to prevent most of the air infiltration; a variety of materials (e.g. spring, felts, foams and plastics) can be used and are available at hardware and building supply stores. Doors should fit tightly to the threshold. Installation of a metal/vinyl threshold may be recommended. To be effective, the vinyl insert should fit tightly against the bottom of the door when closed. Fiberglass insulation should be stuffed under the threshold to stop air currents from entering the structure. An inexpensive alternative to a new threshold may be the installation of a metal/vinyl sweep to the bottom edge of the door.
- Installation of storm doors over all standard exterior doors can reduce heat loss by approximately 40%-60%, when compared to a door without storm doors. However, if the sun strikes on steel or aluminum doors (entrance or storm) that have plastic trim, the heat may melt the plastic. Installation of storm doors over large doors, such as sliding doors leading to a deck, is expensive and may not be economically justified. In such cases, use of insulated draperies may be the wiser choice.
- Caulking around windows and doors should be checked at least annually and maintained in good condition to reduce the amount of air that may infiltrate the structure. Such caulking will also prevent the entry of water, which may cause structural damage.
Heating and Air Conditioning
- Most heating and all air conditioning systems should be serviced annually, and many may require periodic maintenance to ensure a high degree of efficiency and energy savings.
Heat pumps should be serviced annually, at either the beginning or end of the heating or cooling season. The exterior compressor/condenser units should be kept clean and free of all leaves and debris. They should not be covered or otherwise boxed-in, which restricts the free flow of air, thus reducing efficiency and possibly causing damage to the compressor. Generally, the manufacturer’s recommendation is 2 inches clear all around and 5 inches clear above the unit.
- Oil-fired heating systems should be serviced or cleaned annually to ensure that the barometric draft control is functioning properly, that the nozzle is sized properly and clean. An overall burner and system check should also be performed for efficient operation and functionality.
- Gas heating systems require servicing every 2-3 years to ensure they are burning efficiently and to remove rust deposits. Little rust should be accumulating, even after 10 years. If more rust than expected is present, there could be a draft problem or draft-related inequities. The burner flame should be a stable deep blue with a somewhat greenish center; yellow/orange in the flame is an indication of inefficient combustion, while a wavering flame is an indication of a cracked heat exchanger introducing air and thus a waste of energy. However, residential gas units will always have yellow/orange tips. It is when the flame is yellow/orange or whitish that it needs adjustment.
- Electric resistance furnaces and electric resistance baseboard units require little maintenance. Resistance furnaces should be serviced periodically to ensure that all of the heating coils are functioning and the fan motor is properly lubricated. Baseboard units should be vacuumed at least once a year to remove dirt and lint.
- Air conditioning systems should be serviced every year at the beginning of the cooling season. The exterior compressor/condenser units should be kept clean and free of all leaves and debris; they should never be covered or otherwise boxed-in, and shrubs and hedges should be cut back. All of the above restricts the free flow of air, which reduces the gas to liquid process and efficiency of the system. In extreme cases, this may cause damage to the compressor. Window units should be removed during the heating system, because they allow an excessive amount of heat loss when they are left in.
- Air filters on forced air systems, whether the filters are electrostatic, reusable, or disposable, should be checked at least monthly in the heating and cooling seasons and cleaned/replaced as necessary. A dirty filter will reduce efficiency tremendously and, in some cases, (e.g. heat pumps and air conditioners) cause possible damage to the unit (i.e. compressor).
- All duct joints on forced air systems should be tight and sealed with duct tape. It is not unusual to find poorly fitted joints in crawl spaces or attics, which permit conditioned air to escape into these areas or draw in air from these unconditioned areas.
- Ducts and pipes, which transport cool or hot air or water, should be insulated. The insulation should be at least 2 inches thick and, if cool air is being moved through the ducts, the insulation should have a vapor barrier on the outside because moisture only moves one way, from warm to cold. All seams of the insulation should be sealed with duct tape. The insulation used for wrapping ducts or pipes may be special duct wrapping insulation or standard fiberglass batts/rolls. Ductwork in attic areas is chronic conditioned air losers, even insulated ductwork. Ductwork is no match for the relentless temperature extremes that you find in an attic, even with adequate insulation.
- Installation of a humidifier, preferably the evaporator type without a reservoir, on the cold air return, will increase the relative humidity during the heating season and thereby make it feel warmer, while not increasing the temperature. Obviously, such a recommendation is for the forced air systems, but stand-alone humidifiers can be used regardless of the type system, although their effectiveness is somewhat limited.
- Every 8% change in relative humidity (RH) changes the comfort level of the air approximately 1 degree Fahrenheit (F). For example, if in the winter you use a humidifier and you raise the RH in the air 24%, you will be able to lower your thermostat 3 degrees. If you are comfortable when the thermostat is at 70 degrees and the RH is 20%, you will feel the same comfort level if you raise the RH to 44% and lower the thermostat to 67 degrees.
- Humidifiers, regardless of type, require periodic maintenance in accordance with the manufacturer’s instructions.
- Reducing the temperature differential between the inside and outside will reduce energy costs for heating and cooling. This is accomplished by changing the setting on the thermostat (setting the thermostat at 68 degrees F instead of 72 degrees F) during the winter.
- Installation of a setback thermostat, which is a timer, reduces the demand on the heating/cooling system when the house is vacant for relatively long periods of time or at night, and reduces energy costs. If heat pumps are involved, a special, more expensive thermostat is required that wires out the auxiliary heat strips. They have a manual override for times that you demand heat.
- Insulation of a structure is another important factor when considering the comfort of the occupants and energy costs. The “R” value referred to when speaking of insulation signifies the resistance to the flow of thermal energy through a material at 70 degrees F; the greater the “R” value, the better its insulation characteristics. The following are approximate “R” values per inch for the material indicated:
|Insulating material||R value|
- Cellulose and rock wool insulation have much the same insulation qualities as fiberglass, however, they are prone to settling over time, thereby reducing their effectiveness. Moisture in the insulation also reduces its effectiveness, because it changes the density of the insulation.
- There should also be at least a 1-2 inch space between the top of the insulation and the bottom of the roof sheathing for ventilation purposes. Another problem to watch for and caution against is covering soffit vents with insulation, especially the blown-in type.
- Adding attic insulation may be done in different ways. If the insulation already installed is blown-in type, fiberglass batts/rolls of fiberglass may be laid directly on top. If the space between the trusses/joists is filled, and batts/rolls are used, they should be laid perpendicular to the trusses/joists. It is not recommended that heavier type insulation be installed over top of a lighter type (e.g. cellulose over fiberglass, as it will compress the lighter insulation and reduce its effectiveness).
- Recessed light fixtures are not to be covered with insulation, but rather should have a 3-inch clearance on all sides. Covering such fixtures with insulation could cause overheating of the fixture and create a fire hazard.
- Attic doors should be weather-stripped and insulated on the attic side using fiberglass batts, foam sheet, etc. If a vapor barrier is used, it should be against the door or warm side. If the structure has a walk-up attic stairway, the walls should be insulated as well as under the steps, keeping in mind the vapor barrier should always face the heated side of the wall/ceiling. For those attics with pull-down stairs, weatherstrip the door (all 4 sides), consider constructing a cover over the opening in the attic and insulate the box.
- In crawl spaces, insulation should be installed between the joists and against the band joist, completely filling the cavity. The insulation should be at least 5 ½ inches thick, have a vapor barrier facing the heated area, and be held in place by friction, staples or retaining wires.
- Removing an electrical cover plate on an exterior wall and fishing beside the electrical box with a hook can sometimes determine whether or not insulation was installed in the walls. However, the quality of the insulation job can only be determined with infrared photography of the structure. Benefits versus costs of installing wall insulation after construction are considered minimal at best.
- Urea Formaldehyde Foam Insulation (UFFI) is a foam insulation that is usually white to pale yellow in color, it is soft, and crumbles very easily to baby powder consistency. There was considerable excitement about this insulation in the past due to emission of formaldehyde gases, which could cause respiratory problems and allergies. The formaldehyde was used as a binder, as has been the case with some glues/adhesives for decades. UFFI is not now being used. Use of UFFI was generally during the 1973-1983 time frame. Note: It takes 2 to 5 years for the formaldehyde to offgas, depending on the relative humidity in the area and exposure to the sun. The higher the RH, the faster it would offgas.
- Feel the water heater jacket: if it is warm, you should insulate, if it is cool, you do not have to insulate.
- Newer heaters have warnings posted on the jacket not to add an insulation blanket, so be aware.
- When the heater is gas or oil-fired, the insulation should be kept away from the burner area and no insulation should be installed on the top of the heater.
- Heaters should be turned down to approximately 125 degrees Farenheit for safety, however, this could cause spotting of glassware in dishwashers if the dishwasher does not have an element to raise the temperature of the water. If spotting becomes a problem, increase the water temperature by several degrees at a time until the problem is resolved. When the dishwasher has to be replaced, you should consider installing one that will heat water in the dishwasher to the temperature required, thereby permitting the water temperature in the water heater to be reduced.
- Peak timers may be installed on electric heaters so that water is only heated during specific times of the day. However, this concept requires that all activities using hot water (e.g. bathing, laundry, dishwashing, etc.) be accomplished at generally the same time. The electric utility company discounts the rate for the electric that is used through the peak timer.\
- Consider insulating the hot water supply lines wherever they are accessible, using either insulation specifically designed for pipes or 3 ½ inch faced fiberglass insulation, cut to size and held in place with duct tape; the vapor barrier should face the pipe.
Recommended Conservation Measures
- Install storm windows and doors and/or upgrade existing units.
- Install thermal drapes.
- Increase attic ventilation. High-low is the most effective.
- Install attic fan with thermostatic and humidistatic controls and/or upgrade existing unit.
- Install band joist insulation.
- Install insulation on the boiler lines.
- Install insulation on the water lines.
- Install insulation on the water heater.
- Evaluate the weatherstripping and determine the need for more or upgrade the existing weatherstripping.
- Evaluate the basement insulation and need for upgrading.
- Evaluate the existing levels of attic insulation and/or need for upgrading, if necessary.
- Evaluate the existing crawl space insulation and the need for upgrading, if necessary.
- Evaluate and comment on the temperature of the water from the water heater.
- Evaluate installing a timer on the water heater.
- Evaluate installing a “setback” or “programmable” thermostat.
- Evaluate the need for the installation of a humidifier.
- Evaluate the need for the installation of a dehumidifier.
- Inadequate insulation
- Vapor barrier facing the cold direction
- Water lines not insulated
- Missing band-joist insulation
- Window and door opening not properly sealed
- Duct work not insulated or joints not sealed
- Water heater not insulated; temperature above 125 degrees F
- No storm windows
- Inadequate crawl space ventilation
- Exposed lines not insulated