Workings of a Furnace-Mounted Whole House Humidifier

Last Updated: February 26, 2024

The humidity level inside the house can fluctuate depending on many factors. These include a change in weather, seasonal change, water leakage in the structure, and so on. A humidifier is an ideal solution for keeping the humidity from dropping below the required levels, keeping you, your belongings, and your home safe. 

Depending on the area you need to humidify, which humidifier you require differs. A smaller, more portable unit is adequate for single rooms, closets,  storage units, RV’s, etc., however, for larger spaces, and even your entire home, whole-house humidifiers are the best choice. 

The Furnace-mounted whole-house humidifiers are helping a lot of people for keeping their homes cozy. These humidifiers are efficient and save users the trouble of regular interference. Furnace humidifiers cover the entirety of your home, so you don’t have to worry about each area individually. 

In this article, we’ll be discussing furnace humidifiers and how they work. Before we delve into the workings, however, let’s find out more about the humidifier. 

Types of Furnace humidifiers

Furnace humidifiers are a preferred choice of a lot of homeowners. For user convenience, there are a few types of furnace humidifiers that users can choose from, according to their requirements. Let’s find out more about these types. 

1. Reservoir Type Furnace Humidifier

The reservoir type furnace humidifier, also called the drum style humidifier, is the most basic type of furnace humidifier. This type requires a reservoir to contain the water and a rotating drum, which is responsible for creating moisture. Since the model requires a large amount of water in the tank, mold formation is more probable in this type fo furnace humidifier. Users can avoid this by doing regular maintenance. 

This type is quite inexpensive, but in terms of efficiency, it lacks as compared to the other types. 

2. Steam Type Furnace Humidifier 

As the name suggests, this type of humidifier uses water heating to generate the moisture needed for the environment. Steam type furnace humidifiers come with self- regulating steam heater, which boils the water when there’s a requirement and mixes the generated steam into the air for distribution. Water is heated, and the steam is fresh and pure, with little to no chance of impurities. Although these humidifiers are generally more expensive than any other types of furnace humidifiers, they are safer, efficient, and require very little maintenance. 

3. Flow-Through Type Furnace Humidifier

Flow-through type humidifier is aptly named flow-through as it uses the existing water or pipe source to move the water through the unit. The flow carries the water as it drips across a specially coated screen. With the help of a blower, the water then evaporates as the furnace runs. This type of humidifier is more reliable and efficient than the reservoir type humidifier even though it consumes more water. It’s also less trouble when it comes to maintenance, and any excess water that’s leftover drains out. 

These are the different types of furnace humidifiers. Now, let’s move on to the various parts that play a crucial role in the working of a furnace whole house humidifier. 

Additional types of furnace humidifiers also include Disc wheels, spray mist, non-bypass flow-through, impeller, and under duct type. 

Components of a Furnace Humidifier

Water Supply line

The water supply for humidification comes from an existing water pipe, the nearest tap etc. It depends on the location of your humidifier and the closest water supply source. 

Water Valve

The water goes through the water inlet orifice at a reduced capacity, and the water valve helps regulate the quantity of the water flow to the humidifier. It can be a float or a solenoid controlled by the humidistat. 

Water collection unit 

The water collection unit can be a reservoir or an evaporation pad that holds the water for the evaporation process. Water to the evaporation pad comes from the water feed tubes that supply the water to the distribution trough under the top cover. 

Blower 

The blower is also a significant part, as it produces the required air for the evaporation process in the furnace models which need it. 

Drain Pan

The drain pan moves the water coming from the evaporative pads to the nearest household drain. 

Air Duct/Damper

In some models, the air duct on the warm air side provides the air to the unit on the cold- air return. The damper is useful in homes that have central air conditioning. 

Humidistat

A humidistat is a crucial part of the humidifier. It is useful in setting the controls, regulating the humidity, and turning the unit on and off. 

These are the most crucial parts that carry on the workings of various types of furnace humidifiers. Now, let’s see how these parts play their role and run the machine.

So, how does it all work?

Firstly, the steam type furnace humidifier works by heating the water. The water that is in the reservoir is heated by the steam humidifier. Then, the furnace helps in the distribution of the steam throughout the house. The humidistat regulates the process and sends a signal goes to the steam humidifier whenever there’s a drop in the humidity. 

In the case of a flow-through furnace type humidifier, freshwater passes through the system and then drains away. This type typically is mounted to the cool-air return duct of the furnace, and through a humidifier supply takeoff duct, is connected to the warm- air supply. The humidistat or hygrometer lets in the water using the valve when the humidity is low. The heated air goes in the humidifier, and it absorbs moisture from the evaporator pad, and then through cold- air return duct and furnace, return to the warm air stream. In some cases, they’re connected directly to the warm- air supply duct. 

In the reservoir type humidifier, the water comes to the reservoir directly through a pipe. The pan (water reserve) is attached to the furnace. The level of water is adjustable using the float valve. When the humidity is low, the motor inside is turned on, which turns the drum with a wick (foam pad). The wick soaks water from the water reserve, and as the warm air enters the drum from one end, it leaves with moisture from the other end. 

Conclusion

Depending on the type of furnace humidifier, the process slightly differs. But, ultimately, the result is moisturized air.  However, you need to be careful about maintenance, and never let mold or other dangerous things pollute the system. Steam furnace humidifier is low- maintained and safer, but ultimately, you should assess your own house to determine which type suits you the best before making a purchase.