HVAC systems generally require rebalancing with seasonal changes. Warm air rises and cold air falls, requiring adjustments to airflow distribution to ensure the efficient and effective operation of your HVAC system. Tenants are responsible for simple adjustments and basic maintenance of the HVAC system, including rebalancing the airflow when winter gives way to summer and summer to winter. The following information will help you get the most out of your system while spending the least on utilities.
Step 1 – Check Your Furnace Filters
The proper operation of your HVAC system depends on using properly sized and correctly installed furnace filters and changing them regularly. Filters must be sized to fit the cold air returns. Filters are directional and must be installed with the directional arrow (denoting the direction of airflow) pointed into the wall.
Filters should be changed according to the manufacturer’s recommendations. Some inexpensive filters require replacement every 30 days. More expensive filters last longer. Red Door Company recommends using moderately priced pleated filters that last 90-120 days.
Step 2 – Clear Registers and Cold Air Returns
Air must flow freely from the registers to the cold air returns or the HVAC system will struggle to heat and cool the home efficiently. For even heating or cooling in all rooms, the airflow must be balanced. Uneven airflow allotment will cause the temperature to differ throughout the house. Balancing the airflow begins with clearing registers and cold air returns of obstructions like furniture, drapes, or clogged filters.
Registers are usually found on floors and ceilings and sometimes on walls. Most registers look like this: 
Cold air returns can also be on walls or ceilings, and you may have more than one in your house. Cold air returns usually look like this:
Step 3 – Prepare to Balance
Balancing airflow will be faster and simpler if you establish a starting point and make incremental adjustments.
For single story dwellings, begin by opening all the registers fully in every room.
For multi-story dwellings, the starting point depends on the season. To balance furnace airflow in preparation for winter, open the registers on the lowest floor all the way and close the registers on the highest floor. For dwellings with more than 2 stories, open registers on the middle floors half way.
To balance A/C airflow in preparation for summer, open the registers on the highest floor all the way and close the registers on the lowest floor. For dwellings with more than 2 stories, open registers on the middle floors half way.
Step 4 – Identify Hot and Cold Spots
Turn the system on let it run for several minutes. Locate the areas in your house that are being heated or cooled unevenly. We recommend using a thermometer to speed the process of identifying trouble spots. Note areas that are especially hot or cold.
Step 5 – Adjust Vents in Especially Warm or Cool Rooms
Adjust the register levers to open the vents part way in the rooms you feel are too cold in winter or too warm in summer. Just increase the airflow for now; do not open up registers completely. When you adjust the airflow in one room, it has a proportional impact on the airflow in other rooms.
Step 6 – Assess the Heater’s Performance
Run the system for several minutes and check for changes. Remember, increasing or decreasing airflow in one room will have a proportional impact on airflow into the other rooms. Continue adjusting registers until you feel the delivery of warm or cool air is balanced throughout the house. Generally, in a two-story home, downstairs registers are more open and upstairs registers are more closed in winter and vice versa in summer.
Step 7 – Run the Fan
If the weather is exceptionally hot or cold and your system is struggling to heat or cool the house evenly, change the fan setting from “Auto” to “On” and let the furnace fan run continuously. Once the hot or cold spell abates, return the fan setting to “Auto”.
Basic maintenance of your HVAC system, together with seasonal rebalancing, is usually all it takes to keep your home comfortable year-round. If you have any questions, please contact your property manager.
