Heating I Section#1 Furnace - Gas and Oil Quiz#6

This study session deals with the air distribution components in or on the furnace: blowers, filters, and humidifiers.

The estimated completion time for this study session is ninety minutes.

Objectives
At the end of this study session, you should be able to:

• Describe, in two sentences, the two types of blowers.
• List the six problems found with blowers.
• List and describe in one sentence each, the two main filter systems.
• Describe, in two sentences, the workings of a humidifier.

Briefly describe how a bypass drum humidifier adds moisture to the air.

Water in a tray is absorbed by a rotating drum pad. The air blows through this pad, picking up the moisture. This moisture is carried into the ductwork, and distributed around the house.

Briefly describe the components of the 2 styles of blowers you find in residential furnaces.

1. Direct drive blowers have the blower mounted on the motor shaft. 
2. Belt-driven blowers have the blower driven by a belt and pulley arrangement from the motor.

List 2 clues that the blower motor may be too small.

1. Excessive temperature rise across the heat exchanger
2. Poor airflow at remote registers

List 5 conditions which could be found with mechanical filters in furnaces.

1. Missing
2. Dirty
3. Installed backwards
4. Wrong size
5. Loose or collapsed

List 6 conditions that can be found in electronic air cleaners.

1. Dirty
2. Inoperative
3. Improper orientation
4. Missing components
5. Damaged cells
6. Miswired

List 6 conditions that could be found with furnace blowers.

1. Dirty
2. Noisy
3. Inoperative
4. Overheating
5. Rust
6. Poorly secured
7. Running continuously
8. Too small
9. Unbalanced/vibration
9. Loose
10. Damaged or worn belt.

List 6 conditions which can be found with bypass humidifiers.

1. No duct damper
2. Leaks
3. Clogged pad
4. Mesh or nozzle
5. Inoperative motor or solenoid
6. Dirty
7. Poor location.

Why is the location of the bypass humidifier such a concern?

A bypass humidifier mounted over the furnace heat exchanger can cause premature failure of the heat exchanger due to corrosion when the humidifier leaks.

Do our Standards require us to look at electronic air cleaners?

No

How much should a belt deflect when it is under proper tension?

About an inch

Which of the following is not a cause of rust on the furnace fan?

leak in humidifier

condensate dripping from the venting system

high humidity levels in the furnace environment

corrosive chemicals used in the environment

restricted air flow through the blower <selected answer>