Insufficient return air can lead to higher energy bills. When your HVAC system doesn't receive enough return air, it must work harder to maintain the desired temperature, increasing energy consumption. Homeowners might notice a spike in utility costs without a corresponding increase in usage.
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.
If the return duct is too small or there are an inadequate number of return grilles, your HVAC system won't be able to return enough air to recirculate into the system. Again, it's like if you were breathing in through a straw while jogging.
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.
One per room is ideal, but placing two or three in central locations can provide enough air circulation to maximize the energy efficiency of your HVAC and optimize indoor air quality, so your family stays healthy. If your home has multiple stories, you should have at least one return air vent per floor.
However, most HVAC contractors use a rule of thumb to determine the number of air vents needed. For example, for a standard residential HVAC unit, you'll generally need one supply vent and one return vent for every 100 to 150 square feet of living space.
Blocked or Clogged Air Filters
Blocked return vents are common causes of insufficient return air. It is crucial to keep return air vents unobstructed to ensure efficient operation of your HVAC system. Furniture placement, dust buildup, or closed vents can obstruct airflow.
You can add a vent to existing ductwork if your AC can handle it. This can provide comfort in rooms not served by your HVAC system. It can even improve indoor air quality and increase your home's resale value.
Duct replacement costs typically range from around $20–$60 per linear foot, based on our team's market research. For example, if your home has 100 feet of ductwork, a complete replacement can cost between $2,000 and $6,000.
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.
Add Return Ducts
There will be times when even a properly-sized return drop and trunk won't deliver needed air. In those cases, we look for alternative ways to get additional return to the system. Some house layouts are easy to add a floor return in an open area , others require more creativity.
The building codes do not allow “active” returns to be installed in closets.
Typically a 16X20 would be fairly standard for most applications on a 3 ton unit. However if you want superior air flow I would highly suggest putting in a 20X20 as that gives you far better airflow hands down.
Poor ventilation will result in an eventual build up of carbon dioxide and little oxygen, which means you could suffer from shortness of breath, headaches and fatigue.
You should never close your HVAC return vents, but supply vents can be adjusted to improve home comfort. In this blog, the trained professionals at Damiani's Comfort Design explain the strategy behind opening your supply vents and the dangers of keeping your return vents closed.
You should never block your air return vents. Period. However, if you're looking to keep your home cooler in the summer, you can try closing lower supply vents and keeping upper ones open, allowing cooler air temperatures to come in from above and sink throughout your house.
Your homeowner's insurance won't cover cleaning, repairing or replacing your ductwork. What does a home warranty cover when it comes to AC units and ductwork?
A return air drop replacement will run around $300-$400, including installation. In rare cases where a second drop needs to be added, the cost can be up to twice that amount.
OLD HOME, OLD DUCTS
Ductwork has a maximum lifespan of 20-25 years, and starts to deteriorate around year 15. If your ductwork is more than 15 years old, you may need to have the ductwork inspected to see if it is time to replace it. If it is older than 25 years, you almost certainly need to replace the ductwork.
Hiring a local duct installer near you to add a vent to an existing duct system can cost anywhere from $200 to $500, depending on the complexity of the project and your location. This cost includes labor, expertise, and sometimes materials.
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.
Low airflow can make your ears hurt in one room compared to another. Use a barometer to measure the pressure in the kitchen, living room, bedroom, and other rooms in the house. If you notice different pressure measurements throughout the house, this is a sign there's not enough return air.
If your boiler or furnace is in an enclosed space and relies on indoor air for combustion, you run the risk of incomplete combustion, which produces toxic byproducts like carbon monoxide.
While furnaces can stop operating for complicated reasons, home owners should check a few usual suspects first behind a lack of hot blowing air: Electrical problems causing a loss of power. Blocked air vents and ducts restricting airflow. Improperly configured thermostat settings.