FAQ HVAC Questions

  • It’s the single, most important thing you can do for your central heating & air conditioning system!We suggest checking filters monthly. If you have a disposable type filter, (these usually have a cardboard edge), and if it is dirty, just replace it. Don’t attempt to clean it. Some higher efficiency 1″ pleated air filters can go up to three months before needing replacement. But in the higher-use seasons, it’s better to check more often.Different systems have different filter locations. If you don’t know where your filter is located, now would be a good time to locate it. Usually, there is a removable filter access door in the return air duct next to the furnace or indoor unit. This can be in a basement, crawl-space, utility closet, garage, or attic. Sometimes, especially with older systems, the filter is located inside the furnace itself, next to the blower motor. And some systems have a central filter grille installed in a wall or ceiling. The grille swings open, revealing the air filter. Many air filters are directional – the air is meant to flow through the filter in one direction only. Look for an arrow or airflow symbol indicating direction. The arrow should point towards the furnace or air handler. If your air filter does not have any arrows, see if one side of the filter looks rougher than the other side; that would be the side to collect the dust, so the other side would face the equipment.

  • Well this question comes up alot. Other than replacing an air filter, all other maintenance or service should be performed by a trained technician. There are many dangerous components to every heating and cooling system. Hazards including, property damage and even death can result from untrained individuals interacting with heating and cooling systems components. Whiddon’s Air and Electrical highly recommends a service maintenence agreement and leave the dirty work to our team of highly trained technicians. Call us today to schedual an appointment for one of our technicians to assist you with all maintenance on your equipment.

  • We recommend yearly inspections to your equipment.

    Benefits include:

    • Increased dependability
    • Find potential problems and fix them quickly
    • Provide maximum efficiency which lowers energy costs
    • Prolongs the life-span of the equipment
    • Maintains safe and healthy operation
    • Can help to protect the environment
    • Drastically reduces the chance of a break-down which usually happens at night or on weekends when repair rates are higher

    Service Plans may also include:

    • Discounts on repairs
    • Discounts on purchases and future replacement
    • Priority Status for Scheduling
    • Increased warranty duration
  • SEER stands for Seasonal Energy Efficiency Ratio. It refers to the efficiency level of your air conditioner or heat pump. The higher the SEER rating the more efficient the unit is. The minimum SEER is 13 on new units. Whiddon’s Air and Electrical recommends one of our home consultants to help you with your decision with purchasing your next unit. We would be honored to have you as a new valued customer! Call Whiddons Air and Electrical today for a free estimate.

HVAC Common Words

Air Changes per Hour • ACH  

The number of times per hour that the volume of a specific room or building is supplied or removed from that space by mechanical and natural ventilation.

Air Conditioner• A/C  

An appliance, system or mechanism designed to dehumidify and extract heat from an area. Usually this term is reserved for smaller self contained units such as a residential system.

Air Handler [Unit]• AH or AHU

A central unit consisting of a blower, heating and cooling elements, filter racks or chamber, dampers, humidifier and other central equipment in direct contact with the airflow. This does not include the ductwork through the building.

British Thermal Unit• BTU  

Any of several units of energy (heat) in the HVAC industry. One BTU is the energy required to raise one pound of water one degree Fahrenheit. In the US the power of HVAC Systems is sometimes expressed in BTU/hour instead of watts.


Equipment that performs heat transfer to air when mounted inside an air handling unit or ductwork. It is heated or cooled either by electrical means or by circulating liquid or steam within it.


A component in the basic refrigeration cycle that ejects or removes heat from the system. The condenser is the hot side of an air conditioner or heat pump. Condensers are heat exchangers and can transfer heat to air or to an intermediate fluid.


A device that controls the operation of part or all of the system. Most controllers are automatic but have user input such as temperature set points (i.e. a thermostat). Controls may be analog or digital.


A component in the basic refrigeration cycle that absorbs or adds heat to the system. Evaporators can be used to absorb heat from air or from liquid. The evaporator is the cold side of an air conditioner or heat pump.