Bard QERV-A4B Recommended Control Sequences, Ventilation Air Flow, Table Ventilation Air Cfm

RECOMMENDED CONTROL

SEQUENCES

Several possible control scenarios are listed below:

1.Use a programmable electronic thermostat with auxiliary terminal to control the QERV based on daily programmed occupancy periods. Bard markets and recommends the White-Rodgers

1F94-80 (Bard Part No. 8403-034), programmable electronic thermostat for heat pump applications.

2.Use a motion sensor in conjunction with a mechanical thermostat to determine occupancy in the classroom. Bard markets the CS2000 for this use.

3.Use a DDC control system to control the QERV based on a room occupancy schedule to control the QERV.

4.Tie the operation of the QERV into the light switch. The lights in a room are usually on only when occupied.

5.Use a manual timer that the occupants turn to energize the QERV for a specific number of hours.

6.Use a programmable mechanical timer to energize the QERV and indoor blower during occupied periods of the day.

VENTILATION AIR FLOW

The QERV is equipped with a 3 speed motor to provide the capability of adjusting the ventilation rates to the requirements of the specific application by simply changing motor speeds.

TABLE 1

VENTILATION AIR (CFM)

	High Speed	Midium Speed	Low Speed
	(Black	(Blue)	(Red)
CFM
	450	375	300

The units are wired from the factory on low speed. The speed can be changed by switching the toggle switch on the front of the QERV to the desired speed.

The QERV2-A4B is equipped with independently controlled 3-speed motor to provide the capability of adjusting the ventilation rates to the requirements of the specific application and to be able to provide positive pressure in the structure. This is accomplished by setting the intake blower on a higher speed than the exhaust blower.

Manual 2100-310D Page 2