Understanding How a Whole-home Humidifier Works

Dry indoor air is an extremely common problem during the winter. The colder the outdoor air temperature is, the less humidity there is in the air. This is why it always feels much drier in the winter than in the summer. The problem is even worse when your furnace is running as it will basically suck most of the remaining moisture out of the air and cause your home to be even drier.

A whole-home humidifier is the most effective option for overcoming dry winter air so that you can breathe easier. These units are sometimes referred to as “furnace humidifiers” since they add moisture to the hot air coming out of your heating system. Here’s what a whole-home humidifier is and how it works.

The Difference Between Portable and Whole-home Humidifiers

Humidifiers work by heating water to the point where it evaporates and then pumping out this warm, moist air to increase the indoor humidity level, and this is true for both smaller portable units and whole-home humidifiers. The difference between a portable and a whole-home unit is that whole-home humidifiers work in conjunction with your heating system so that the moist air is circulated throughout the building to increase the humidity level in the entire home. Portable humidifiers have no real way to circulate the moist air and thus will only be able to raise the humidity level in one room or area.

Where Are Whole-home Humidifiers Installed?

Whole-home humidifiers are installed directly inside a building’s ductwork to increase the moisture content in the hot air produced by the furnace. These units can either be installed in the return duct where cold air enters the furnace or in the supply duct where hot air exits the furnace.

If the unit is located inside the return duct, it raises the humidity level of the air before it is heated. A humidifier located in the supply duct adds moisture to the heated air before it is circulated throughout the home. Both options work equally well, but it is almost always better to have the unit installed within the return duct before the furnace if possible.

Unlike portable humidifiers where you constantly need to refill the unit’s water reservoir, whole-home humidifiers are connected directly to your home’s cold or hot water supply. A pipe is run from a nearby water line and feeds into the humidifier to supply it with water. There is always the potential risk of the pipe springing a leak or that water could start leaking out of the humidifier itself.

If the unit is installed within the supply duct, it will typically sit directly above the furnace. This has the potential to cause major issues if the humidifier or water line leaks as the water could easily drip inside the furnace and damage its components or cause an electrical short. If the unit is installed in the supply duct, leaks won’t be as major of an issue since no water would ever be able to enter the furnace and damage it.

How Whole-home Humidifiers Work

Whole-home humidifiers are designed to run whenever the furnace is currently producing heat. As soon as the furnace kicks on, the humidifier will also start running and pumping out moist, warm air. In drier climates, the humidifier will generally run every single time the furnace is heating and will continue to pump out moist air until the furnace shuts off. As soon as the thermostat signals the furnace to shut down, the humidifier will also stop since air is no longer being circulated through the duct system.

In less dry climates like that of Florida, a whole-home humidifier may not run every time the furnace is heating and instead may only need to operate a few times a day. In order to determine when it needs to run, the humidifier uses something known as a humidistat. This is similar to a thermostat except that it measures humidity instead of temperature.

The humidistat enables you to program the system based on your desired indoor humidity level. Most experts recommend that your home’s humidity level stays constant at around 50% moisture saturation. If you program the humidistat to this percentage, the unit will only ever run when the humidity level is below 50%. As soon as it reaches 50%, the humidifier will automatically shut down even if the furnace is still running. This ensures that you have complete control over your home’s humidity to prevent any issues that can occur when the air is either too dry or too moist.

At Dr. HVAC Inc, we install and service a range of indoor air quality equipment for residents of Margate and the surrounding areas including whole-home humidifiers and dehumidifiers. Our technicians also specialize in the full range of heating and cooling repair, maintenance, and installation services. If you have any questions about managing your home’s humidity or need any other cooling, heating, or indoor air quality service, contact us today.

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