Dirty filters, leaky ducts, and poor insulation can cause cold return vents. Leaky ducts often cause cold air to blow even after cranking the heat up. 20-30% of air, especially hot air, is lost because of leaky ducts. Cracked, holey ductwork needs sealing or replacement.
Return vents tend to be bigger than supply vents, and you won't feel any air coming from them. When an HVAC system delivers air to a room, it increases that room's air pressure. Return vents exist to remove the extra air.
For your furnace to run efficiently and your home to heat evenly, this airflow must be in balance. In other words, the amount of air that your furnace “breathes in” must equal the amount of air it “breathes out.” Cold air returns are what allow your furnace to “inhale” your home's air.
Ensure that all the ductwork connections are sealed properly on the interior and exterior points of the ductwork. You can seal gaps using metal tape, foaming insulation spray, or mastic sealant. You do not need to remove any existing sealant and may build up the sealant over top of any current filler.
The heat exchanger uses coils to transfer heat from the ignited gas to the air. When cold air blows from a furnace the heat exchanger, furnace burner, or exhaust are likely the cause. This may be due to dirty components, broken parts, or the many safety mechanisms within the gas system.
Dirty filters, leaky ducts, and poor insulation can cause cold return vents. Leaky ducts often cause cold air to blow even after cranking the heat up. 20-30% of air, especially hot air, is lost because of leaky ducts. Cracked, holey ductwork needs sealing or replacement.
You Have Cold Air Blowing Out The Vents When The Heat Is On Because of a Dirty Air Filter. Hiding in the filter of your heating system is dirt and debris. If you aren't cleaning it regularly, this will accumulate over time, leading to problems with your heating system's efficiency.
Should Return Air Vents Be Open Or Closed In Winter? Once again, NEVER close a return air vent. If you have operable cold air SUPPLY vents in your home, you can close upper supply air vents and keep lower return air vents open in the winter to keep your home cozy while allowing your heating system to work efficiently.
**Clogged Air Filter:** A dirty or clogged air filter can restrict airflow, causing reduced air output from the vents. Check the air filter and replace it if it's dirty or clogged. 2. **Blocked Vents:** Make sure that all vents are open and unobstructed.
Now, from the example above, with 75 degree air being pulled in at the air filter, what temperature should we expect to be blowing out? Well, the general consensus is somewhere between 14 to 20 degrees colder than the intake temperature. From my example, 55 to 61 degrees would be an acceptable range.
While it can be tempting to block the cold air returns for rooms you're not using to save energy or place furniture against them to arrange a room, blocking these registers is one of the most common ways to undermine your cooling and heating system.
Down Low: if you have your air return lower on your wall it will function better as a cold air return. This will allow your air return to draw in cold air as it sinks to the bottom of the room. Making it more efficient at recirculating this cold air through your furnace to repeat the heating cycle.
Use your vacuum cleaner's hose attachment to clean the return's interior and surrounding areas. Then use a soft-bristled brush to clean the grille thoroughly. Wipe down the grille with your microfiber cloth and cleaning solution before reinstalling.
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.
Return vents are usually larger than supply vents and are in large rooms in the home. The return vents in your home help equalize the pressure that changes as your HVAC system heats or cools your home. These vents should never be fully closed because closing them off restricts airflow and strains the system.
A low level of refrigerant is normally the result of leaks within the air conditioning system, which usually originate from a fitting, faulty valve or the evaporator coil itself. Since the chemical blend typically evaporates as it leaks out, any dripping will hardly be noticeable.
Common Issues with Return Ducts: Clogs and Leaks
The blockage usually comes over time, by a buildup of dust and debris that just accumulates until it begins choking the system. To alleviate this, perform consistent air duct maintenance, as well as utilize the help of a professional with professional HVAC maintenance!
Obstructed Vent
One of the most common causes for poor airflow is a blocked vent. To properly heat or cool your home, the air needs to be unobstructed. To see if there are any blocked vents, look by the baseboards or on the ceiling. Furniture, bedding, and the vent damper could all be possible obstacles to the vent.
Signs of an air duct clog include: One room in your house is hotter than all the others. Dirty air coming from vents. Unusual spikes in electric bills.
Reduced efficiency: Your HVAC system will work less efficiently if you block a return air vent. This will make the units use more energy and will raise your utility costs.
Does Every Room Need Air Return Grilles? 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.
Maintenance Needs
Return vent filters, if used, also need regular replacement to avoid airflow issues. By properly maintaining both types of filters, you can get great airflow, reduce strain on your HVAC system, and rest easy knowing you have cleaner air.
Accidentally leaving your thermostat set to "cool" or setting the fan to "on" can cause cold air to come out instead of hot air. It also could have run out of batteries. Either way, the solution here is simple. Head over to your thermostat, make sure it has plenty of battery, and verify that the heating function is on.
Blower Motor Problems
If your blower motor isn't working correctly, you may experience cold air blowing from the vents. Check for loose connections or have a technician inspect and replace the motor if needed.
If your reversing valve has a leak inside, it's splitting the refrigerant from the hot to the cool side. To check this in the heating mode, compare the temperatures of the suction line from the outside to the suction valve at the bottom. If the difference is more than 3°F, the valve needs to be changed.