Where Should the HVAC Register Be on Each Wall? Because heated air rises, return registers should be installed high on the wall. In the summertime, the return registers will be well-positioned to pull the hottest air out of a room.
Return air vents are usually found in the lower wall of a room or hallway. Ideally, your return air vents and supply vents should be on opposite sides of the space. Otherwise, you may be pulling some of the heated or cooled air back into the system before it has a chance to circulate.
Up High: having an air return higher up on a wall will be better at sucking in hot air that rises. Making it more efficient at transferring this hot air back into your system to repeat the cooling cycle. Down Low: if you have your air return lower on your wall it will function better as a cold air return.
Placing the supply registers in the floor is most efficient becasue heat rises. Normally they are placed around the perimeter of the house where the room is coldest. Some would argue that it is better to place them on the inside walls and take advantage of natural convection.
Return air vents should be located at the interior of the room, and preferably in the ceiling. Air, heated or cooled will basically set up a ``wall'' of heated or cooled air and then move that air towards the interior of the room. That provides a more even and efficient system.
In winter, enable the bottom cold air to return and in the summer, enable the upper return. It's that simple.
Ideally, every room except the kitchen and bath should have its own return air grille. At the very least, each level of the house should have one. Even so, many homes were built with just one or even no return ducts in an attempt to cut costs.
Efficiency and Air Flow
Further, adding the vents here prevents your home from having a convection current that draws cold air in. It instead buffers the cold air from outside and prevents cross drafts which could make you less comfortable in your home during the winter.
For optimal comfort, supply registers need to be installed on outer walls and under windows, whereas return registers are ideally located on inside walls.
This means that a 10-foot by 12-foot bedroom (120 square feet) would need one air vent, while a 20-foot by 20-foot family room (400 square feet) would need two or three.
Hot air rises and cool air sinks. Therefore, opening the right return vents in the summer and winter significantly improves the distribution of air by your forced-air system. You'll also enjoy more even heating and cooling throughout your home. In the summer, open your high returns and close the low ones.
Symptoms include weak airflow and uneven cooling or heating throughout your home, with some rooms feeling much cooler or warmer than others. Homeowners should regularly check vents for consistent airflow. If you notice a significant drop in air pressure or uneven temperatures, it could indicate return air issues.
Instead, there should be at least one return vent in every room, with two or three being ideal. If your house has only one return vent, this is not a problem — make sure to keep the doors open in every room so the air can circulate properly. Make sure there are no furniture, draperies, rugs, etc. blocking return vents.
Air Ducts Near the Ceiling Are Most Effective
Many people don't realize this because it is common to see air vents located near the floor in older homes. With vents near the floor, however, furniture often ends up blocking vents and causing the air to get trapped.
1. Openings shall not be located less than 10 feet (3048 mm) measured in any direction from an open combustion chamber or draft hood of another appliance located in the same room or space. 2. Return air shall not be taken from a hazardous or insanitary location or a refrigeration room as defined in this code.
While return vents don't always require filters, adding them provides additional filtration, improving indoor air quality and keeping dirt and debris out of your system. However, there are pros and cons to consider.
To maintain an even temperature throughout the room, return air vents should ideally be positioned higher on the walls or near the ceiling to capture the rising warm air effectively.
Usually, a register is placed near a window or door, which is where the greatest heat/cooling loss occurs. In contrast, returns (grilled ducts which suck air back into the HVAC system for heating or cooling) are usually placed in the wall or ceiling nearest the center of the building.
Return registers can be large and centrally located in your home, or they can be in every room. HVAC professionals recommend that each room have a cold air return vent to help with flow and temperature control. These vents are typically found on an interior wall.
For heating, floor registers should go near windows or interior walls. For cooling, ceiling registers should go over the center of the room or above windows to optimize air circulation.
Trickle vents are required by Building Regulations when replacing windows that already have trickle vents fitted. For new window frames that are replacing old windows without vents, it must be demonstrated that ventilation will not be made worse by the installation of the new energy-efficient window.
While living in the south, you may have noticed that extreme heat is more common than extreme cold. If you remember basic science, you'll know that hot air rises, and cold air sinks, making ceiling vents the delivery location of choice for places that often experience warmth and humidity.
If you have a combined heating and cooling system and need to decide between placing the return vents high or low, consider your climate. If you live in cooler climates, it might be wise to install them towards the floor, whereas if you reside in warmer areas, they should ideally be installed close to the ceiling.
Adding a return air vent will cost homeowners $350 per vent on average, depending on the vent size and duct material. A professional can assess the right duct material you need for your home and can give you an accurate estimate.
If there's not enough return air, your living room can be 10℉+ warmer or cooler than, for example, the bedrooms. Not enough return air in summer can cause rooms close to the central unit to be cooler and those farther from it to be warmer. In winter, rooms farther from the furnace can be too cool.