Balancing your forced air heating system ensures all the rooms in your home are at the right temperature. Understanding of the room heating demand, individual preference and good amount of patience is required to get it right.
When the outdoor temperature is the same and the insulation of the building should be consistent, good or bad, what causes some rooms to be cold and others too hot? Balancing the forced air system will ensure all variables are considered.
5 steps to find the balance in your home heating system
1. Working from the furnace find the ducts that lead to the rest of the house. Some defining to ensure we are all on the right page;
a. Ducts that take air to the various rooms of the house typically run off the furnace in large square plenums, which are warm (depending on time of year) and running under floor joists. These square ducts may also quickly transition all or some of the air into smaller (6,8,10”) round ducts.
b. Cold air returns are on the opposite side of the furnace pulling air from the house to the furnace. Cold air returns typically are flat tin nailed onto joists and cold to touch.
c. The furnace pushes warm air to the house through the ducts and draws air through the cold air returns.
Work your way from the furnace along the ducts finding the levers which activate dampers inside the ducts. Open all ducts by turning the lever parallel to the duct which provides maximum airflow.
2. Registers in each room are another area that air flow can be adjusted, open all registers completely.
3. Turn on the heat and start checking room by room temperatures. Often room temperatures take some time to adjust. Attempt to check temperature in the center of the room at about the same height from the floor.
4. Adjusting both the dampers on the ducts and the registers until the right temperature is achieved in each room for each use or user.
5. Once the right temperature has been reached mark the lever (w for winter) handle so that a starting point is easy to find next heating season.
Repeat the process for the cooling season, except write an S (for summer) where the damper handle should be positioned.
5 reasons there is room to room temperature changes.
The assumption is that all parts of the building are insulated equally and the outdoor temperature is the same therefore the cause of uneven temperature room to room. Balancing the forced air system takes all considerations into the equation.
1. Distance from furnace; the further the duct travels the less air and ultimately heat will reach the room. Typically forced air systems consider distance and initiate a run with a large volume duct reducing diameter as it extends from the furnace. Suggestion; inline fans can work at drawing warm air into a room.
2. Room is over a cold area; unheated crawl spaces or rooms over garages typically have challenges as the air cools due to limited insulation. Suggestion; increase insulation, alternative heating sourced in these rooms.
3. Windows; even the best windows have lower performance than solid walls. Windows can be a source of heat loss and heat gain depending on exposure and season. Suggestion; insulated window blinds are a great convertible option.
4. Exposure; a general term relating to the orientation of the home and more specifically one room compared to another. Take two rooms, one with full sun exposure and the other little sun and full wind, which will need more heat? Rooms with excessive windows or corner rooms will require more heat than a small room with limited windows and a short exterior wall.
5. Furniture; even the best systems and house hold insulation can be foiled if furniture blocks the free flow of air out of a heating duct. Suggestion, move furniture or get deflectors to let heat out away from furniture.
Routine filters changes and yearly professional inspections of your heating system extends the life of your furnace. Balancing the system is often a game of trial and error over cold winter nights, to be replayed each season.