It doesn’t get more uncomfortable than lying in bed on a hot summer night. You move constantly in an effort to put your skin in contact with any cold portion remaining on your sheets and pillow, but it doesn’t do any good. You might end up surrendering to the heat and constructing a makeshift bed on the couch in the basement. This scenario is common in far too many households today—often times the issue is with the home's return air ducts.
Return air ducts are to blame for imbalanced temperatures resulting in a scorching top-floor, south-facing room and a chilly basement in the same house. If the ducts aren't sized and placed properly, you’re doomed to live the above scenario forever.
Installing Return Air Ducts
A return duct should be located in every room except the kitchen and bathroom, where fumes which you don’t want to spread around the house are generated. Think of your HVAC system as a recirculation pump; it’s simply pumping air instead of water. You need to get air back to the pump at the same rate and from the same rooms where air is being delivered. That’s why one central return air duct doesn’t do the job effectively.
When you’re looking to add return air ducts to your existing home, you have a few options:
- Convert wall cavities into ductwork: A contractor simply cuts a hole in the floor where the return register will be located. Then the wall cavity is lined with sheet metal up to the point where it connects to your existing return air system.
- Convert a laundry chute: Two-story homeowners may choose to sacrifice the laundry chute for the cooling cause. This conversion is usually tremendously successful.
- Utilize a pantry or closet: Often this closet lines up with an interior hallway upstairs, making for a fairly straightforward duct installation.
- Collect second-floor air in flexible pipes installed in the attic: These pipes connect in a central location where all the air circulates down into the furnace room.
- Build ductwork: As a last resort, you can build a duct run from scratch in the corner of the room. You can build another one several feet away and build a bookcase between these juts in the wall for a natural, built-in look.
Balancing Return Airflow
Haphazardly installing a few return air ducts here and there won’t cut it. Get the biggest bang for your return-air buck by ensuring the contractor you hire knows about balancing return airflow.
Once the installation is complete, you can further control airflow by installing grill covers that feature operable louvers. This lets you close certain registers, such as those in rooms you use sparingly or in rooms that need less heating and cooling. Do not, however, close more than 20 percent of the system’s registers or you could create more pressure than the system can handle.
Reverse Airflow in Older Homes
If your home is 80 years old or older, it probably has reverse airflow, which means supply ducts are installed in interior walls and one giant return register is located in a main area, such as at the bottom of a staircase.
This is all wrong. Supply ducts should run through exterior walls, preferably with registers under windows or near doors, to stop drafts as they form. A single large return register does nothing to promote cross ventilation and even temperatures in every room. If this situation exists in your home, you might need to redo the entire duct system with the help of a knowledgeable contractor.
Sizing HVAC Equipment
Proper sizing and placement of return air ducts is essential for home comfort, as is properly sized HVAC equipment.
- Undersized equipment obviously has the drawback of not being able to keep up in extreme weather.
- Oversized equipment has short cycles, which means it turns on for a few minutes, supplies mass quantities of hot or cold air, and then shuts off again. This causes uncomfortable temperature fluctuations, distracting and noisy operation, higher energy bills and improper humidity control. Air conditioners need to run for a certain amount of time to remove moisture from the air and prevent a clammy feeling. Then, whole-house humidifiers can only add moisture to the air while the furnace is running.
To learn more about sizing return air ducts and HVAC equipment, contact Comfort24-7.com. Our contractors proudly serve homeowners in Chicago, as well as northwest Indiana and southwest Michigan.