1. uneven distribution of hot or cold air
   unsupported ducts
2. tilting ducts

The result may be an uneven distribution of hot or cold air.

1. furnace malfunction
   improperly set ducts and registers
2. blower malfunction

The cause may be improperly set ducts and registers.

1. parallel to the top and bottom of the ducting
   perpendicular to the top and bottom of the ducting
2. at a right angle to the top and bottom of the ducting

When in the open position, the damper will be turned parallel to the top and bottom of the ducting.

1. Increase blower speed.
   Decrease blower speed.
2. Raise thermostat temperature.

To increase the flow of warm air, raise the speed of the blower.

1. Increase blower speed.
   Decrease blower speed.
2. Decrease thermostat temperature.

Decreasing the blower speed may decrease the noise.

1. wool
   fiberglass
2. foam

Fiberglass insulation may be used to wrap ducts.

1. oil
   coal
2. wood

Forced-air systems are fueled by electricity, gas or oil.

1. rewarmed
   distributed
2. both answers

The cold air is rewarmed and distributed.

1. distributing cooled air
   no other purpose
2. removing smoke

A forced-air system may also be used to distribute cooled air from a central air conditioner.

1. noise
   air blockage
2. both answers

Forced-air systems rarely malfunction, but big problems may involve noise and airflow blockage.

1. dirt
   blocking the registers
2. both answers

Dirt and furniture items blocking the registers may cause airflow blockage.

1. Turn furnace on.
   Turn furnace off.
2. neither answer

Run the furnace while balancing the system.

1. Increase thermostat temperature.
   Decrease thermostat temperature.
2. Adjust the pulley on the blower motor drive.

To change blower speed, adjust the pulley on the blower motor drive.

1. blower noise
   decrease in distribution system efficiency
2. both answers

The result may be an increase of noise from the blower and a decrease in efficiency of the distribution system.

1. carpenter's square
   carpenter's level
2. ruler

Use a carpenter's square to check for alignment.