Feeling uncomfortable in our homes can be an unpleasant experience. Unbalanced HVAC systems lead to poor energy efficiency, increases utility bills, poor air quality, and decreased indoor comfort. If you are experiencing these issues, your home might need air balancing.
HVAC systems integrate two ductwork branches: return and supply. Supply ducts deliver cool or heated air to our rooms and buildings. Return ducts bring the air in our rooms and buildings back to the A/C or furnace. Air balancing ensures equal amounts of volume of air are distributed and returned proportionally.
If you are experiencing higher utility cost while certain rooms are harder to heat or cool, this could be a sign of improper air balancing. Rooms further away from the air conditioner or furnace have duct runs longer than other rooms. Long duct runs can cause a decrease in supplied volume or air. Ductwork located in the attic also increases the chance of uncomfortable rooms. Attics usually are the exact opposite temperature of the air inside the duct line. The longer the duct run, the more time the air inside the duct spends in an unsavory attic environment. Adjusting the thermostat to compensate uneven room temperatures, causes longer cycles which increase energy used. Higher utility cost is the net result.
Rooms with only a supply duct providing cool or warm air is fine- as long as the door to the space the return is located remains open. When doors to rooms are closed, the return path is eliminated. When air paths are cut off by closed doors, the air being supplied to the room pressurizes the room. Less air can now be delivered because of the pressurized room. Rooms that are now back pressured causes disproportionately delivered air to other rooms where air is being sucked out- which sucks more air out of the rooms supply ducts. When rooms suck out more air, we increase outside air being pulled into the room from structural gaps and cracks, and improperly sealed doors and windows. Outside humidity and air pollutants enter the room unfiltered. The result leads to uncomfortable rooms where temperature balance cannot be maintained. Another note of concern with depressurization, is the backdraft of gas fumes from gas-fired appliances like hot water heaters and furnaces. Two-Story homes that have a centrally located return on the second floor is often done to cut cost when building the home. Unfortunately, this practice leads to the forementioned problems.
The good news- we can fix your problems! There are a few different solutions to restore proper air flow, reducing energy usage, and improving indoor air quality. Proper air balancing results in homes that maintain a slightly positive air pressure. The first step is a qualified technician to measure air flow volume in each room. Some of the easier fixes include adjusting internal dampers and correcting duct leakage issues.
Depending on the room layout and initial construction- if returns can be added to individual rooms that lack returns, this is your best option.
Installed in a wall or above a door, transfer grills provide air pathways from a room to the central return
As the name implies, air is jumped from one room to another. Placed near the door, sheetrock is cut, and a jumper duct grille is installed in the ceiling. Another grille is placed in the ceiling by the central return. Ductwork is run through the attic connecting the two grilles. This allows air to flow from a pressurized room to a room that is depressurized, creating more equalized airflow. For every cubic foot of air that traveled through the jumper duct- it allows a heated/cooled cubic foot of air out of original rooms supply duct.