When builders put together home automation systems for their customers, HVAC is rarely on the list. Most builders are more than comfortable installing traditional energy-efficient, set-back thermostats and don't have any intention of changing until more customers start asking for automated HVAC.

Aprilaire is starting to alter that equation, at least for custom builders. With its model 8870 thermostat, Aprilaire was one of the first to develop an industry model for integrating HVAC with most standard home automation systems.

Joe Hlavacek, a product manager for Aprilaire, says the 8870 lets builders integrate multiple thermostats with standard home automation systems from AMX, CorAccess, Crestron, and Elan using just one Cat-5 cable. Hlavacek says the 8870 connects to the home automation systems via an adapter that changes an RS232 computer signal into an RS485 thermostat signal. The RS485 signal goes through a distribution panel that routes any changes to one or multiple thermostats throughout the home.

Homeowners looking for thermostat-free walls can also opt to use remote sensors in selected zones throughout the house. The sensors, which can be painted or wallpapered over, send climate information back to the thermostats, which can be placed out of view in closets or utility rooms.

"Builders think of HVAC as a separate entity,'' says Hlavacek. "But with prices coming down for automation and people spending more time at home, the HVAC system is becoming a natural for buyers to specify after security and lighting. The basic idea is for homeowners to get all the services on one point-and-click screen."

Hlavacek says consumers stand to save 20 percent annually on home heating costs by automating HVAC systems and programming temperature levels based on use throughout the house. Automating HVAC with the 8870 typically costs about $500 to $600 per unit, but total costs vary based on the system the integrator installs.

Automated HVAC: Integrating HVAC into a standard home automation system is still found mostly in custom homes, but that will change as the technology becomes more affordable and easier to install.