How to Position Supply and Return Ducts Correctly
- Height Considerations. Return vents are flexible when it comes to height. ...
- Room. Proper AC register placement promotes even cooling throughout the house. ...
- Window Placement. We recommend installing air supply vents right under the window opening to cool any outdoor air entering your home.
What's the best location for return air ducts?
What's the Best Location for Return Air Ducts? Supply air from furnaces and air conditioners should be on outside walls. The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room. If the supply ducts are in the floor, then the return air should be located up high.
What are return ducts in air conditioning?
Return air ducts channel air from rooms back to the air handler. They’re connected to the air grilles you might find on the walls or ceilings of your hallways and larger rooms. The return ducts help maintain good air circulation, preventing hot and cold spots, and keeping your rooms from feeling stuffy.
Where are my supply ducts located?
If so, your supply ducts may be on inside walls. You may have a single giant return air grill on the floor or at the bottom of a staircase. This is all wrong. Supply ducts should be located on outside walls, preferably under windows and near doors.
What happens if you don’t have a return duct in your home?
That’s right, your heating and air system is nothing more than a big circulation unit. Without the return duct, the air in the home would not be able to properly circulate. This would not only cause your energy bills to rise, but it will cause your entire system to not function at full efficiency.
Should return air ducts be high or low?
For optimal efficiency, it's ideal to have return registers installed. To ensure efficiency during the cooling season, your home should have high registers. High return registers draw hot air that rises to the ceiling back into the system to repeat the cooling cycle.
How many return air ducts should I have?
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.
Do you need return air ducts in every room?
While it is a myth that air return grilles are required in each and every room in the house, it is definitely necessary to have more than one of these grilles installed at strategic places in the house. The most important place to have these would be the bedroom.
Can you have too many air returns?
To answer your question, no, you normally cannot supply too much return air. If installed in a certain fashion, with bedroom doors closed, it is possible to put a single room or two under negative pressure but that won't affect the amount of heat entering the room substantially.
What happens if there is not enough return air?
Not Enough Return Air Vents Each area that is receiving a measured amount of air should also be able to return the same amount of air to the system. If the return is not sufficient: The area becomes pressurized. The amount of airflow it can receive is limited.
Can a house have too many return air vents?
Having several return vents (ideally one in every room, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine. Keep the doors to each room open so air can properly circulate.
How far away should a return vent be from a supply vent?
Ideal Distance Between a Return Vent and a Supply Vent In most cases, the distance should be at least 5 feet.
How long can a return air duct be?
Duct Size - Single Return For most systems, the minimum duct size (see Table 1) is sufficient for up to 25 feet (8 m) with no more than three 90° bends.
Can you have 2 return air vents?
Having several return vents (ideally one in every room, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine. Keep the doors to each room open so air can properly circulate.
Why do I have two air returns?
Having two air return vents allows you to seasonally control which air is returning to the HVAC system. In older homes, this may not be an option. The theory is that in the Summer cooling season, you want to be circulating warmer air back through the HVAC system to be cooled.
Can a return vent be too big?
Return ducts and vents cannot be too big. A big grille won't help if the duct is small.
How many vents should a house have?
But how many roof vents does one home really need? A general guideline is homeowners need one square foot of roof vent for every 300 square feet of ceiling space, if your home has a roof with a vapor barrier, or 1:300. If not, you should have one square foot of roof vent for every 150 square feet, or 1:150.
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Where should HVAC return air ducts be?
"An HVAC return air duct should be in every room except a bathroom and kitchen. They should be on interior walls across the room from the supply ducts that should be washing exterior walls with conditioned air."
Where to put return air?
It's best to put them on an interior wall across the room from the supply duct. © 2018 Tim Carter
Why does my furnace need return air?
The reason for return air is simple. Your furnace is simply a recirculating pump. Instead of pumping water, it is pumping air. We need to get the air back to the pump. Furthermore, without a return air duct in each major room, the supply duct air has to "push" all of the air in the room out of the way as it makes its way towards you.
What is the air duct in your house?
The air ducts in your house should be designed exactly like the blood vessels in your body. Think about it. The veins and arteries supplying blood to the different parts of your body, even out to your fingers and toes, are the same size as the veins and arteries returning that blood back to your heart.
What is the purpose of a return air grill?
The intent is to wash the exterior walls with heated or cooled air. You are trying to combat the heat or cold at its source. The single giant return air grill in the floor balances the load at the furnace motor but does nothing to promote cross-ventilation in each room.
How to get the most bang for your return air buck?
If you want to really have a way to get the most bang for your return air buck, think of installing grill covers on the wall that have operating louvers. This will allow you to choke down rooms possibly on the first floor that are drawing too much air.
Where should the air conditioner be located?
Supply air from furnaces and air conditioners should be on outside walls. The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room.
Who installs return ducts?
Return ducts are installed by the HVAC contractor. Return duct locations should be indicated on the HVAC design plans. Tasks associated with this installation should be included in the contract for the appropriate trade, depending on the workflow at a specific job site.
Why install ducted returns?
Install ducted returns to address pressure differences in an existing home.
What is a ducted return?
Install ducted returns or a combination of ducted returns, transfer grilles, jump ducts, and/or door undercuts in bedrooms to allow pressure balancing between bedrooms and the rest of the house in homes with ducted heating and cooling systems by providing a path for room air to return to the central air handler, thereby increasing the volume of conditioned air circulating in the room.
How to determine if an adequate pathway exists for air to return to centrally located returns?
To determine if an adequate pathway exists for air to return to centrally located returns, the following room-to-room pressure measurement can be used: Turn on the air handler to high. Close all interior doors. Using a manometer, connect tubing to the input port.
What is return air pathway?
Return air pathways that leak will draw air from unintended places in the house and can lead to undesirable pressure differences. A fully ducted return system will be easier to air seal and will have better airflow characteristics than building cavities used as return air pathways.
Where to place tubing from manometer?
While standing in the center of the house or hallway, place the tubing from the manometer under each door and record the pressure difference from each room with respect to the main body of the house (note the presence of a negative or positive sign).
Can building cavities be used as return air pathways?
Do not use building cavities as return air pathways.
Where do you put your ducts?
If you make a careful not you will probably notice right away that most of your supply ducts are either installed by the windows or doors. This is because this is where most heat enters the home. The ducts are installed strategically in these locations to help battle this heat loss or heat gain. And, this is just one of the reasons that the return ducts need to be installed directly across from the supply vents.
What Exactly Is A Return Ducts Function?
A return duct is the part of the system that carries the air back to the furnace or air handler where it will then be circulated back out through the supply vents. That’s right, your heating and air system is nothing more than a big circulation unit. Without the return duct, the air in the home would not be able to properly circulate. This would not only cause your energy bills to rise, but it will cause your entire system to not function at full efficiency. Since the return duct is basically applying negative pressure to the system it is the one that houses the filter.
Why is it important to clean air ducts?
You also learned that return ducts aren’t supposed to be installed in bathrooms and kitchens because they will just circulate the odors and moisture from the rooms throughout the duct system. This is just another reason why cleaning the air duct is important. A dirty return duct will just cause the system to circulate dust and debris throughout the home over and over again.
What does it mean to choke down ducts?
Choking down the ducts that are located on the first floor or close to the return duct will allow you to allocate more air to the ducts that don’t have as much suction power.
What is a supply vent?
The supply vents would be the vents that blow air into the home. Even though your filter is located in-line with the return duct it is one that is oftentimes forgotten about. Of course, it could be forgotten about during the installation because without the return duct the system just wouldn’t heat and cool the home properly.
Do return air ducts work?
Yes, some systems are designed to work this way, but most modern duct systems will just usually have one or two returns accounting for the entire system. And, these systems are more than effective. But, before you think about installing a new return air duct you should think about cleaning air duct service to make sure your ducts are clean ...
Do you need a return duct in every room?
Now, this does not necessarily mean that you need a return in every room.
How far away is the return air inlet from the unit?
These rooms could be 50' away ( laterally) from the return air inlet and yet the occupants comfort isn't compromised and so locating the return air inlet 6' higher or lower on a wall isn't going to make any measurable difference.
Where are heat registers placed?
Some heating authorities opine that more effective and economical design places these registers on the interior walls - the outside walls and perimeter of some rooms may be chilly even when the heat is operating.
What is short circuit in ventilation?
Short-circuiting of ventilation air occurs when ventilation air enters and leaves a space or duct before it has a chance to mix well enough with the room air to do the job it was intended to do - that is, to adequately dilute pollutants, or to break up stratified air in the occupied space.
What are the features covered in depth?
Features covered in depth include: descriptions of typical styles, characteristics and requirements, testing, listing, reporting, certifying, packaging and product marking.
Where is the octopus furnace located?
Our photo above shows an octopus furnace located in the basement of a pre-1900 home. All of the return air to this system is drawn from the un-heated basement floor - a "one-way" air movement heating design that increases heating costs as well as risking pick-up of dust, debris, or anything else undesirable from the basement area.
Is it dangerous to cut an air register?
At UNSAFE DUCT OPENINGS we describe other air register location mistakes that can be dangerous, such as cutting a return air opening near heating equipment or in hazardous areas like a wet moldy crawl space .
Is a stairway a good location for an air return duct?
If you are asking whether or not the of of a stairway is a good location for an air return duct opening, my view is yes it is, particularly for air handling system when it is in cooling mode. That's because warm air rises in buildings; locating an air return where warm air naturally rises (up the stairwell) .
What is return air duct?
Return air ducts channel air from rooms back to the air handler. They’re connected to the air grilles you might find on the walls or ceilings of your hallways and larger rooms. The return ducts help maintain good air circulation, preventing hot and cold spots, and keeping your rooms from feeling stuffy. Balanced airflow prevents indoor pressure ...
Why do return air ducts matter?
Return air ducts play a significant role in your home’s energy efficiency. Why Return Ducts Matter. Your duct system has two types of ducts: supply and return. The supply ducts channel conditioned air from the air handler out to the air registers in your rooms. That is, they supply your rooms with warm or cool air.
What to do if your home has no return ducts?
If you find your home has insufficient return ducts, ask a heating and cooling technician about adding more. In some cases, additional ducts can be installed in the wall cavities and connected with the main return duct. Depending on the construction of your home, however, your technician may opt for other methods. Door undercuts and transfer grilles can also help ensure sufficient return airflow.
Does every room in a house have a return air grill?
Optimizing Your Return Ducts. 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.
Can door undercuts help with return airflow?
Depending on the construction of your home, however, your technician may opt for other methods. Door undercuts and transfer grilles can also help ensure sufficient return airflow. Maintenance matters, too. Make sure your return grilles aren’t blocked by drapes, furniture or other items that could interfere with airflow.
