FAQ
HVAC System Design
When replacing an older furnace, proper air movement is crucial for efficiency. For example, a 95% efficient furnace will move more air at lower temperatures than a less efficient furnace. This means ductwork upgrades may be required to get the most out of your new furnace.
Which is the best system for my home or condo?
Matching the size of the old equipment is not accurate since windows and insulation may have been upgraded. Older ducting may not be capable of handling the additional air requirements of new high efficiency furnaces. If you do not move the proper air through these furnaces, you will not get the advertised efficiency and will probably have nuisance fault problems. Air conditioner capacity also requires minimum air requirements to prevent freezing and excess condensation. Duct condition, air leakage and insulation are also directly linked to total system efficiency.
Why is a properly sized system important? And which system is best?
Bigger is not better! The furnace or air conditioner should be sized to meet the needs of the home under the most extreme conditions. This is usually an 80 degree temperature difference for heating and a 20 degree difference for cooling. Oversized equipment requires larger ducting and tends to cycle on and off excessively. Systems that have short run times do not condition and circulate the air resulting in uneven temperatures and uncomfortable air.
An oversized heating system cycles frequently and runs for short periods of time, creating uneven heating and using more energy. Likewise, a system that is too small will run constantly, costing more, and not effectively heating the residence. An oversized air conditioning system will also cycle for short periods of time, not properly removing humidity from the air. This means the temperature will have to be lowered for comfort, leading to a cold, damp condition. A properly sized air conditioning system should run constantly, and even loose two to four degrees during the most extreme weather.
Benefits of a Two-Stage, Multi-Stage or Modulating Furnace
Ideally a system that runs all the time and only adds the amount of heating or cooling that is being lost, is the most efficient and comfortable way to condition a space. This is the concept behind a two-stage, multi-stage or modulating furnace.
Which brand of equipment is best?
The answer depends on your specific needs. Even the least expensive furnace or air conditioner, though, can last for years with few problems if installed properly. Proper installation is the single most important factor affecting the operation of any equipment.
Is assistance available?
The United States government offers a variety of rebates and tax credits when you purchase energy efficient equipment.
