Home Retrofit

Tech tip: Optimizing central heating systems


In the last two decades, a high-efficiency central forced-air heating system has changed from a high-end consumer product to a practical necessity in most homes. What can an HVAC specialist do to improve the efficiency of a home that has already received a high-efficiency heating upgrade? Distribution efficiency and controls are two key opportunities.

Inspect the system to maximize distribution efficiency
The entire distribution system should be inspected during any heating system upgrade to:

  • Ensure it meets optimum duct velocity ratios
  • Confirm the pressure is balanced
  • Identify energy losses within the system

A distribution system can lose energy through air leaks and thermal conduction. To cut energy loss, make sure ducts have adequate insulation and are sealed properly with mastic. (Energy Trust’s incentive for duct insulation require duct sealing for incentive eligibility.)

Upgrade controls
Advanced control units are inexpensive to install and can help save energy. Homeowners may need extra assistance to get the most benefit out of these sophisticated systems.

  • A graphical thermostat control interface might offer weekly programmable schedules, provide local weather conditions and even connect with a smartphone or computer. While consumers may love the vast number of control options, the complexity can be overwhelming. As an HVAC technician, you are best equipped to teach homeowners how to operate a new control unit. Show them how to program a weekly schedule that optimizes energy efficiency and comfort for their lifestyle.
  • For heat pump systems, effective control is especially critical and complex. When backup resistance heat kicks in, a heat pump system becomes as much as three times more costly to operate. Advanced controls minimize the use of backup heat. The control system uses an external temperature sensor to determine if the heat pump will sufficiently heat the home, and locks the resistance heat during that time. (With web-enabled products, such as a Nest thermostat, local weather data is retrieved from the Internet.)

A house is a system, and all parts of the system must work together to optimize efficiency. HVAC is no exception to this rule. Many installers already understand the value of optimization because it maximizes the number of customers who are fully satisfied with their new heating equipment.