How To Your Home’s HVAC System: Heating, Cooling, and Ductwork


IMPORTANT: A semi-annual service contract with a qualified HVAC (heating, ventilation and air conditioning) contractor to inspect and service your heating and air conditioning equipment will keep your system operating efficiently and extend its life.


Keeping Your Home Comfortable

Due to changes and variances in temperature and humidity, your heating and air conditioning system is one of the more important features your home has to offer. Inspect the combustion chamber in gas-fired furnaces to be sure a bright blue flame is visible along the entire length of burner pipes. A yellow flame or excessive scaling, rust or soot indicates improper combustion and/or a possible leak in the heat exchanger that could allow combustion gases and carbon monoxide to enter your living area. This potentially dangerous situation requires professional inspection and repair. Electric heat requires little homeowner maintenance. Simply be observant, and if the unit does not seem to be heating adequately, or must run all the time, call your HVAC contractor to evaluate it. If the system is installed in midsummer, it cannot be checked for operation of the heater. At the first sign of cool weather, you should turn on the heater to check it. Even if heat is not yet needed! The first time you turn on the heat, the unit may blow smoke for a minute or two because of the oil used on the furnace to prevent rusting during shipment. (This could cause your smoke detector to sound its alarm.) Your heating and air conditioning system not only controls temperature but also controls the humidity in your home. Do not leave windows or doors open while your system is in operation. If they are left open, condensation will form on the air conditioning vents and on the inside of the windows. Often, this moisture will stain the drywall or woodwork and may cause the unit to freeze up, possibly causing permanent damage.


Thermostats and Controls

Visually inspect the wall thermostat for any damage or missing parts, and repair as needed. Programmable thermostats have a battery that must be changed if the LCD readout indicates the battery is weak. There is also a “fan limit switch” that ensures greater energy efficiency. If the blower either runs continuously after turning off the heat or shuts off immediately, the fan limit switch may not be functioning properly; a qualified HVAC contractor should service the unit. Your air conditioning may include a “set-up, set-back” thermostat to keep a comfortable temperature during those hours you’re at home; and to run on more efficient temperatures when you’re away or asleep.


Outside Condenser Units

Maintaining your cooling equipment is largely a matter of keeping the inside and outside units clean. This means a regular filter replacement or cleaning program, an occasional duct cleaning (every five years) and keeping the outside unit clear of weeds, dirt, debris, coil pings, and dents from lawnmowers, baseballs, etc. Inspect coil fins for damage and make repairs if needed. HVAC contractors have special tools for straightening bent coil fins. Manufacturersrecommend at least two feet clearance around and five feet above the unit. Remember that dirt and dust are insulators and they, therefore, make it more difficult to transfer heat from the inside air to the transport medium (refrigerant) and ultimately from the outside coils (Condenser) to the outside air. Listen for unusual fan or motor noise that might signal impending failure. Watch for fire ants that may invade the unit and cause serious problems. Use of an insecticide around the condensing unit to control fire ants is a wise preventive measure.


Energy Efficiency

Electric Compressors and Heat Pumps are now rated (for cooling purposes) by their “Seasonal Energy Efficiency Ratio” or “SEER”. The SEER is the ratio between the total cooling output during the normal season divided by the total electric power input for the season. For example, a 10 SEER means that the BUT/h is ten times the input. The higher the SEER, the lower the operating cost and the higher the efficiency. However, past a certain SEER level more is not necessarily better because the system can cool the house off too fast to remove significant humidity from the air. A properly cooling system should drop the temperature 15 – 23 degrees across the inside coils (evaporative coils). Remember, however, that on an extremely hot day you may not get the same performance. Air Conditioning, by definition is the equipment’s ability to drop the inside temperature 15 degrees below outside temperatures. Therefore, if the outside temperature is 95-105 degrees, and the inside temperature is 80 degrees, then we have properly operating air conditioning. Try to keep your thermostat set at 80 degrees if you are relaxing and 75 degrees if active.


Condensation Drains

Most air conditioning systems feature a double drainage system. The primary drain is connected into your main plumbing system. An auxiliary or back-up drain from your air conditioner is tied into a pipe leading outside your home. While this drain acts as a back-up system, it also can be considered a “red flag” warning that your primary drain is not functioning properly. If you notice water coming from the auxiliary drain, you should inspect the primary drainage system for an obstruction or blockage in the pipes. To kill fungus and keep your air conditioner running smoothly, pour one cup of a 50/50 solution of chlorine bleach and water into the opening at the condensate drain line where it exits the evaporator coil. Doing this in Spring and Fall will also prevent condensate from backing up into house and flooding the area. Check the flow of water through the condensate drain by observing flow at its termination or the flow of water in the pipe. If the drain does not flow freely, simply blowing it out may solve the problem. This drain line should terminate at least five feet from your home’s foundation to prevent a wet area at the foundation edge. If the system is installed in midwinter, it cannot be checked for operation of the cooling. At the first sign of warmer weather, temperatures averaging above 60 degrees Fahrenheit, you should turn on the air conditioning system to check it… even if cooling is not yet needed.


Ductwork and Air Filters

The single most important thing a homeowner can do to keep the HVAC (heating, ventilation, and air conditioning) system operating at peak efficiency is to keep the return air filters clean and properly secured in place. The filters should fit snugly. If they lift when the blower comes on, unfiltered air is bypassing the filter. The heating and air conditioning filter should be changed on a regular basis. For best results, we suggest installing a new filter every 30 days. A good overall filter is a pleated polyester type. If you have allergies try an electrostatic filter. These require no external power source and can be purchased in various sizes. In a perfect world, the electrostatic filter would be cleaned monthly. Also, be careful not to block the return air grill with furniture or other obstructions.


HVAC Ductwork

Significant amounts of conditioned air can be lost to the attic through leaky ducts. Inspect ductwork for leaks at connections and joints, proper support, tight bends and general condition. During the 1980s a flexible duct with a gray plastic covering was used extensively. This gray plastic covering deteriorates in attics. Damaged ductwork should be replaced as necessary. If there are rooms in your home that are not being used, we suggest that you shut down the airflow to those rooms, this can be done by closing the register or vent located in the ceiling, floor or wall of each room. This serves two functions: heating or cooling is not wasted in an unoccupied room, and you increase the airflow to the rest of your home.



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