When we think about cooling or heating our homes, what comes to mind is the temperature setting. Rarely do we think about humidity and its role in making the air in our home moist or dry. For most people, this is because their HVAC unit already takes care of the humidity issue and ensures the air is comfortable.
But what happens when your HVAC unit is not designed to manage your home’s humidity automatically?
That’s where a humidifier comes in.
To understand this concept, let’s define humidity first.
What is Humidity?
Relative humidity refers to the level of water vapor in the air. It is measured in percentage and indicates how much water vapor the air can hold before it becomes liquid (condensation). For example, when relative humidity is 50 percent, it means the air holds half the amount of water it can before condensation happens.
To determine your home’s exact humidity levels, you need a hygrometer to measure water vapor. Most local hardware stores will stock these, and they are not expensive.
The amount of water in the air plays a significant role in your home’s comfort. If humidity is too high, the air feels moist and murky, which is quite uncomfortable. High humidity primarily occurs when it’s hot because the air can hold more water.
On the other hand, low humidity leaves the air feeling dry. In the winter, it feels like the air is cutting through your skin, which leads to skin issues like dryness and itchy eyes.
The secret is to have a balance where the air is not too moist or too dry. According to experts, the ideal house humidity is between 30 and 50 percent. This is subject to some adjustment depending on how hot or cold the outdoor temperature is.
Also known as a whole-house humidifier, a furnace humidifier connects directly to the HVAC system to moisten the warm air your furnace is pushing throughout your home. The humidifier holds a water reservoir.
Naturally, moist air feels warmer and more comfortable to the skin, hair, and nostrils. This means you don’t have to crank up the heater to make your home warmer during the winter. As a result, the furnace uses less energy, and that saves you money.
Furnace humidifier settings affect the amount of moisture released with the air. During the summer, the HVAC unit should not add any moisture to the air because it’s already moist. In the winter, however, the settings will be determined by how dry the air feels and how cold it is outside.
Here’s what you need to know about humidifier summer/winter settings.
Best Humidifier Setting for Summer
Heat is not the only thing that’s high during summer; the humidity is high too. Besides feeling sticky and muggy, high humidity can also cause hyperthermia, or overheating. Other effects include the following:
- Mold growth
- Discomfort when sleeping
- Damage to furniture, wooden musical instruments, and wooden floors
To combat this, you want a humidity level between 40 percent and 50 percent. You can achieve this balance in two ways depending on the kind of unit you have.
First, if your HVAC unit and furnace are old, you should not turn off the humidistat completely. Instead, leave the humidifier setting to low, so it’s still working but not too much. This is because fighting the summer heat can be too much for the AC, and the humidifier helps cool things down a bit.
If your unit is modern, the humidistat should have several humidifier settings. One of those settings is Summer or S, and the other one is Winter or W. Turn the switch to S, and it will work the same way we have described above.
At this setting, the AC will do what it normally does and absorb most of the humidity from the air, leaving your home cool and comfortable.
The humidistat (humidifier thermostat) can be located on the return air plenum near the humidifier or the wall near your AC thermostat.
Best Humidifier Setting for Winter
Conversely, when the outside air is extremely cold, the humidity goes down. This is because cold air holds less water vapor.
Interestingly, dry air has worse effects than humid air. Some of them include:
- Static electricity build-up
- Easy spreading of viruses and bacteria
- Dry and itchy skin and eyes
- Damage to wooden furniture, floors, and musical instruments
- Sinus reactions
- Chapped lips
- Nose bleeds
During the winter, the furnace humidifier setting should be high to supply enough water vapor to the air. If you have a modern HVAC unit with a humidifier, the W position on the thermostat will suffice.
In fact, you should add a portable humidifier and some live indoor plants to increase moisture in the air. The best humidity level during the winter is 20 percent to 30 percent.
Can you use portable humidifiers in place of the whole house humidifier?
Absolutely. Portable humidifiers are relatively inexpensive, though you might need to buy one for each room. When the indoor air is cold and dry, the humidifier will add moisture to the air and keep your room habitable.
However, they come with a couple of issues. Firstly, you need to fill the canister with water daily and then turn it on. This means the humidifier may not provide a constant moisture supply.
Secondly, portable humidifiers need to be cleaned regularly. This ensures the moisture coming from it has no bacteria, mold, or other microorganisms that can be harmful to your health.
For these reasons, a furnace humidifier is ultimately the best way to moisten your home during the winter. Because it is connected directly to your HVAC unit, it constantly works with no supervision needed.
If you are concerned that your furnace humidifier is not working as it should, consult a trusted professional to check it out. Sometimes, the issue may not even be your humidifier. For example, it could be your insulation.
Again, only a professional can advise on the best way forward to ensure the air in your home is comfortable all year round.