HVAC Zoning forTwo-Story Homes

Two-story homes in the Las Vegas valley face a unique cooling challenge. During the summer, heat naturally rises to the second floor, while the cool air from your air conditioner settles downstairs. The thermostat is usually located on the first floor. When the downstairs reaches the set temperature, the thermostat shuts the entire air conditioning system off. This leaves the upstairs bedrooms warm and uncomfortable. The Las Vegas climate makes this issue even more noticeable. With July bringing an average high of 104.5 degrees Fahrenheit, and about 78 days a year reaching 100 degrees Fahrenheit, your cooling system works incredibly hard. Outdoor units sit in direct sun and dust, pushing cold air through the house. When that cold air cannot reach the second floor evenly, it creates a frustrating living environment.

Many homeowners wonder if they need to purchase a second air conditioning unit. In some cases a second system makes sense. A more practical method for many houses is HVAC zoning. A zoning system divides your home into different areas, or zones, giving you separate temperature control for each level.

How an HVAC Zoning System Works

A zoning system uses motorized dampers installed inside your ductwork. These dampers open and close to send air where it is needed. Instead of one central thermostat controlling the entire house, you have multiple thermostats. You might put one thermostat downstairs and a second one upstairs. These thermostats connect to a central control panel.

When the upstairs thermostat calls for cooling, the control panel opens the dampers leading to the second floor and closes the dampers leading to the first floor. The air conditioner pushes the cold air only to the area that needs it. This lets you set the bedrooms and the living room separately.

Important Ductwork Considerations

Before installing a zoning system, the condition of your existing ductwork must be evaluated. According to ENERGY STAR, in a typical house about 20 to 30 percent of the air moving through the ducts is lost to leaks, holes and poorly connected ducts. Pushing air through a zoned system requires tight, well-sealed ductwork to function correctly. If your ducts leak, the conditioned air will escape into your attic or between the walls before it ever reaches the registers.

• Duct sealing improves the air delivery to the farthest rooms in the house.
• Duct size matters when dampers close part of the system.
• Airflow balancing helps each zone get its share of air.

Equipment Sizing and Compatibility

Zoning works best with certain types of heating and air conditioning equipment. Single-stage air conditioners run at full capacity whenever they turn on. If a single-stage system tries to push its full volume of air into just one small zone, it can cause air pressure issues and excessive noise. Variable-speed or two-stage systems often pair better with zoning. These systems can run at lower capacities, matching the specific amount of air needed for the calling zone.

Your current air conditioner also needs to be properly sized for the home. When looking at replacement estimates, it is important to look at the whole home before recommending a size. This includes the rooms, insulation, windows, sun exposure, the existing ductwork, and how the family uses the house.

Maintaining Your Zoned System

A zoned system requires the same regular maintenance as a standard system, plus a few extra checks for the dampers and controls. Maintaining your equipment helps it manage the intense Las Vegas heat. Remember to check the filter every month and change it at least every three months, as recommended by ENERGY STAR. A dirty filter restricts airflow, which puts unnecessary strain on the blower motor and the compressor.

You should also have a cooling tune-up performed in the spring. A technician will check refrigerant pressures and temperatures, rinse the outdoor coil, check and tighten electrical connections, and clear the condensate drain line. For gas furnaces, a heating tune-up in the fall is important. The CPSC says fuel-burning heating equipment should be inspected every year.

How Kestrel Heating & Air Can Help

If you are tired of dealing with uneven temperatures in your two-story home, we can help you evaluate your options. Kestrel Heating & Air provides thermostat and zoning installations across the Las Vegas valley. We will find the cause first, show you what is happening, and give a written price before any work begins.