Jeffrey Anderson | Improvement Center Columnist | January 30, 2012
Times change and by the late '60s and early '70s many new houses were being constructed with HVAC systems to help families beat summer heat. Early systems were expensive to operate; due to continual improvements, the HVAC types available today are more energy efficient, and do a good job of keeping homes cool on hot summer days.
3 modern HVAC types
Most homes today are heated and cooled with a forced air arrangement that pushes conditioned air out into rooms through a series of supply vents. These vents are located in just about every room, and larger spaces may have several vents. As conditioned air circulates through a home, it's gradually pulled back to the HVAC system through return registers and the process starts again.
This forced air system works with HVAC systems such as:
- Heat pump: The electric heat pump is based on early HVAC designs, but has been refined since those early models. This system has an indoor air handler, and an outdoor condenser, which work together to pull heat out of the home during summer, and pump warm air back into a home when switched into heating mode. When outdoor temperatures drop to a point where there isn't much available heat to pull back into your home, resistance heaters kick in to supplement the system. Most thermostats have a light that indicates when your HVAC system is using this more expensive heating source.
- Split system: Newer homes often have a split system featuring an indoor gas furnace, and an exterior, electric air-conditioner. Many families prefer the warmth of gas heat, and on cold days, this system can be less expensive to operate than the resistant heat of heat pumps.
- Dual fuel: This system is a recent development and has become popular with homeowners desiring the ultimate in energy efficiency for their homes. A dual-fuel arrangement uses an electric heat pump, when outdoor winter temperatures are moderate, but switches to gas heating, when a heat pump's expensive resistance heat would normally start up.
The size of your HVAC system is normally based on the square footage of your home, and factors such as insulation and the size and location of your windows are also considered. Most HVAC contractors prefer to do a load calculation on your home before they quote pricing.