How to Install a Humidifier on a Furnace? – A Complete Guide on Whole-House Humidifier

Written by Priyanka

It is apparent to find dryness in the air during winter causing trouble while breathing, skin itching, sore throat and a lot more. People with allergies, asthma, and similar breathing issues have to deal with sore throats. The easiest solution in this scenario is to get a humidifier to maintain optimal moisture levels in the room.

To take it one step further, getting a whole house humidifier can provide you a better resolution like improved air quality, ease with respiration, comfort to skin, and eyes and a lot more. So, getting a whole-house humidifier is the perfect choice for people who have HVAC installed.

The market is flooded with a huge variety of humidifiers for the whole house. However, one should make sure of four key features in a quality humidifier – capacity, water auto-refilling, drain pipe and safety features. If you have bought a whole-house humidifier, then let’s begin with the installation.

Let’s Begin with the Preparation

If you are new to the use of a humidifier and buying it for the first time, then it is recommended to set a baseline by checking the humidity levels in your house.

There are many types of humidifiers that you can choose from as every one of them is capable of fulfilling the need. However, the right type helps with effectiveness, easier installation, and efficiency. Consider factors like the number of rooms in your house or the area of your house, moisture level in your house, and type.

Choosing the right Type: There are two types of HVAC – forced air and central heat pump. Both types of HVAC have ductwork. So, you can choose a humidifier based on fan-powered, bypass model or stream functionality. Here, we will be sharing the installation of furnace-mounted humidifiers.
Taking Permission: In some regions, it is mandatory to obtain necessary permits from the municipality before installing a humidifier. If not required in your case, you can still check online for better clarity.
Getting Extra Supplies: While installing a humidifier, you might need some extra supplies such as a long water supply, plumbing valves, extra-long drain pipe and whatever you feel is required based on your HVAC installation in the house.

After completing the initial work, it is time to check everything you bought and read the installation manual that came with the humidifier. Even though we are sharing a universal installation guide, some humidifier models have different requirements based on the working mechanism.

Installation Guide for Humidifier on Furnace – A Step-By-Step Guide

Step 1: Finding the Perfect Place for a Humidifier Template

It is necessary to find the perfect position for the humidifier in your HVAC duct. Some brands recommend installing the duct in the supply vent whereas some recommend it in the return vent. You can find the template for cutting holes in the humidifier box. So, place it in the location where you want to install and draw with the market for making the perfect cut.

Step 2: Cutting Hole for Mounting Plate

After marking the installation location on the duct, remove the template. Take a drill for the pilot hole. Then trace the hole on the edge of the template markup. Keep cutting the template shape, but make sure that you avoid cutting on the outer side of the marked template. Usually, most humidifier brands require a 4-inch diameter hole in the duct. Make sure that you wear protective gloves to protect yourself against the sharp edge of the duct that you cut. Now use the mounting plate to check the hole size and if you need to fix anything at all. If everything seems right, remove the thin plastic cover from the gasket and place the template to stick it. Take the screws which came with the installation kit and fix the humidifier mounting plate.

Step 3: Repeat the Same for Installing Humidistat

Next, you need to repeat the process for the humidistat that monitors humidity levels in your house and adjusts the humidifier setting accordingly. A humidistat is usually installed in the return vent to indicate how humid the air is in your house. Trace with mounting plate cut holes and install with screws to affix gasket for humidistat. You can install the humidistat now and use the screws that came inside. Once done, it is time to plug in the humidistat to power. Some models require manual wiring to the HVAC and thermostat. If you don’t feel comfortable with electric work, then leaving this work to profession will be the perfect choice.

Step 4: Connecting Humidifier to Mounting Plate

If you are leaving the wiring work to the electrician, then you can work on connecting the humidifier now. If otherwise, then use the humidifier installation guide to wire the humidistat. The wires of the humidistat will be connected to live wire for power and three wires will come to the humidifier to control humidity levels. This is the time to install the humidifier using screws to the mounting plate and wiring it accordingly.

Step 5: Water line and Drain

Before working on running the water line to your humidifier, it would be a great idea to install the drain first. If anything goes wrong with the water line, you will have a drain to take care of the extra water.

Firstly, look for the drain at the bottom of the humidifier and take a plastic drain tube from the humidifier kit to attach to the same. If there is no drain tube, then you can consider using ¾-inch PVC pipes and connecting them to the drain. Now, connect the drain pipe to the nearest floor drain or condensate pump.

After completing the drain, you can look forward to installing the water line. Take the water supply line from the humidifier kit and install it to the nearest water pipe. After connecting one end, take another end of the water line and install it in a humidifier compression fitting using a wrench for no leakage. After connecting it, opt for connecting the saddle valve fitting and making sure that the valve is off or pierced.

Step 6: Installing the Bypass Vent

Once you are done with the installation of the drain and water line, it is time to install the bypass vent. Trace bypass collar for the vent in the duct but to the opposite side of the humidifier body. Now, make a hole and use kit screws to secure the collar. Once completed, you can attach a flexible duct to the collar and attach the humidifier body.

Step 7: Testing Everything Now

This is the time to check whether every fitting is perfect or not. Turn on the water supply to your humidifier and look for leakage. If you don’t find anything, then look at the saddle, drain pipe and other places to ensure everything is working right.

Turn on your whole-house furnace humidifier and check for leaks from the water line, drain, and compressor valve. Once you have looked out for everything, it is time to turn on the power supply to your humidifier. Now connect your humidifier to the thermostat, and look for the moisture level in the house.

The perfect moisture level for quality time and healthy respiration is between 30% to 40%. If the humidity levels in your house are lower than this number, then set it to the desired level and you are good to go.

Benefits of Installing Humidifier on Furnace in Your House

A room with optimal moisture level offers many unnoticed advantages that most people don’t pay attention to. If you are installing a humidifier in your house during this winter, you can find several advantages. These are as follows:

Better Indoor Air Quality: The air quality in your house will improve with the humidifier as it maintains consistent humidity levels. You can find no skin dryness in your house. This difference in air quality is visible from the very first day of installing a humidifier.

Reduction in Airborne Irritants: Dry air is prone to more dust particles in the air and similar irritants which can make it difficult to breathe normally. People who have issues with irritants will find a huge difference in inhaling air.

Skin Advantages: Dry air takes away moisture from your skin and turns it dull. Having a quality humidifier in your whole house will create a huge difference in skin quality and glow. Your skin will be less itchy and moist.

Other Health Advantages: Sore throat is one of the biggest issues with dry air. Most people suffer from sore throat during winter due to dryness in the air. Humidifier helps relieve sore throats, enhance eye comfort, and also reduce the transmission of airborne viruses.

- Preserve Household Items: Humid air Prevents wood from cracking, warping, or shrinking due to dry air. Also, Proper humidity levels maintain the structural integrity of delicate items like pianos, guitars, and paintings.

Convenience: Having a humidifier on the furnace is more convenient than using a portable humidifier in many ways. Your whole house has maintained a humidity level that suits your throat, skin, and health. Auto-refilling in the humidifier also makes things easier in the long run.

Other advantages like customization and automation help modernize your home and get the best out of your humidifier. Hope, this guide will help you learn the importance and installation method of humidifiers.

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