How to Install a Humidifier in a Downdraft Furnace

An old downdraft furnace.

Humidifiers release moisture into the hot air released by a downdraft furnace. The installation of a humidifier to a downdraft furnace includes three components: electrical wiring, water hookup and ventilation. This process takes a little bit of time but is not challenging once all of the parts that come with the humidifier are identified.

Things You'll Need

• Screwdriver
• Voltage meter
• Wire stripper
• Wire clamps

Instructions

Wiring

1. Find a place where there is a water supply near the furnace.

2. Find the cut holes for the humidifier. Humidifiers are different, so the instruction manual will be needed.

3. Place the mounting hanger on the wall where you intend to place the humidifier. The mounting hanger will have to be screwed in with screws that come with the humidifier. That's where the screwdriver comes in.

4. Place the basin on the mounting hanger. Screw the basin to the mounting hanger.

5. Place the humidistat on the wall near the humidifier. Use your screwdriver to screw the humidistat into the wall. Make sure you place the humidistat in a place where the humidistat can be reached.

6. Check to make sure the power is turned off. In order to be sure, use a voltage meter.

7. Attach the supplied wire on the humidistat to the junction box on the downdraft furnace. The insulation on the wire might need to be stripped in order to run the two wires together.

8. Attach the other supplied wire on the humidistat to the wire connected to the motor on the humidifier.

Water

1. Turn off the water supply.

2. Screw the saddle valve body on to the faucet where the water supply is located.

3. Screw the insert halfway into the valve on the side of the saddle valve body.

4. Screw the compression sleeve on to the insert.

5. Screw the expander on to the other end of the compression sleeve.

6. Screw the compression sleeve into the basin.

Air

1. Find the air takeoff on the furnace.

2. Attach the flex ducting on the humidifier to the air takeoff.

3. Use wire clamps to keep the flex ducting attached to the humidifier.

Tips & Warnings

• If the supplied flex ducting isn't long enough, longer flex ducting can be purchased.

• Make sure that the power supply is turned completely off. Make sure that the damper can be easily opened and closed.

References

• Just Humidifiers
• Installing Humidifiers on a Downdraft Furnace
• All Experts

Resources

• Information on Humidifier Installation Costs