If your home feels humid even though the air conditioner is running, the first step is determining why the system or home is not properly controlling humidity.
At Guardian Heating & Air, we take a whole-home approach. We start with the mechanical equipment, verify that the system is properly sized, and, when necessary, evaluate the home itself for pressure, infiltration, duct leakage, attic conditions, and air-sealing issues.
The goal is to test first, identify the actual problem, make the appropriate corrections, and then test again to verify the results.
The first thing our technicians inspect is the mechanical equipment.
We look for:
- Impacted or dirty coils
- Incorrect blower-speed settings
- Static pressure within the duct system
- The system’s overall refrigerant charge
All of these items can affect how the air conditioning system performs and how well it handles humidity inside the home.
Guardian evaluates these conditions using our Vitals Report, which allows us to look at how the HVAC system is operating as a whole rather than focusing on just one component.
If everything checks out with the mechanical equipment, our next step is to validate that the HVAC system is sized correctly for the home.
With newer construction, the homeowner may already have an energy calculation that we can review. If that information is unavailable, Guardian can perform a load calculation to determine whether the equipment is appropriately sized for the space.
There are many factors that go into properly sizing an HVAC system. Even a small error in the information entered into a load calculation can change the results altogether. This is why it is important that the information used to perform the calculation is accurate.
If the mechanical equipment is operating properly and the system is correctly sized, the next step—if the homeowner wants to dive deeper into the issue—is to evaluate the home itself.
Guardian can measure the pressure inside the home in Pascals using specialized equipment that allows us to compare the pressure inside the home with the pressure outside. This can help identify whether the home is operating under negative pressure.
From there, we can perform a blower door test to determine whether the home is suffering from excessive air infiltration and help identify where leaks are occurring.
We can also inspect the attic to determine whether it is properly ventilated and whether the ductwork is properly sealed.
An improperly sealed duct system can leak CFM from the air conditioning system into the attic. This can create a pressurized environment in the attic while contributing to negative pressure inside the conditioned space.
That negative pressure can pull hot, humid air into the home, contributing to:
- Humidity problems
- Indoor air quality problems
- Increased energy use
Once we have a full understanding of the issues within the home—whether that is improper attic ventilation, leaky ductwork, or a lack of air sealing—Guardian can develop a prescribed remedy based on what we actually found during testing.
Testing may identify air leakage around top plates, drywall connections, wall voids, or other areas allowing the home to pull air from the attic space.
Depending on what we find, Guardian may recommend:
- Insulation removal
- Attic air sealing
- Insulation installation
- Duct sealing
Some projects may require multiple contractors working together. In many cases, Guardian can perform much of the corrective work because we performed the testing, identified the problem areas, and marked where corrections need to be made.
After the corrective work is completed, we can perform another blower door test to verify the results, as well as another load calculation on the home.
If roof penetrations or additional roof ventilation are required, Guardian will typically work with a roofer so they understand where ventilation needs to be added.
A whole-home dehumidifier is a great option in Florida for homeowners looking for lower indoor humidity levels and better overall indoor air quality.
Dehumidifiers can also be a good option for attic spaces, particularly homes with large spray-foamed attics.
Because these attics are sealed from outside influence, humidity can become trapped inside the attic space. It is important to treat a spray-foamed attic much like conditioned space, which means addressing the humidity in that space as well.
For homeowners in Jacksonville, a whole-home dehumidifier can be introduced into the conditioned space to help control humidity.I would also recommend considering a dehumidifier for a home with a spray-foamed attic, especially when there is a large volume of attic space.