Lifebreath 2500EFD, 2500IFD specifications Fan Defrost, Location, Mounting

Fan Defrost

The Models 2500IFD and 2500EFD are equipped with an electronically controlled fan defrost system to remove frost that collects on the warm air side of the aluminum heat transfer surfaces of the heat exchanger core. When the outside temperature drops below 27˚F(-3˚C), a defrost timer is activated which provides for an auto- matic defrost cycle. During the automatic defrost cycle, the fresh air supply is shut off while the exhaust fan continues to operate. Both the times between defrost cycles and the length of time spent in defrost are adjustable (see pg. 9 for details). This allows warm inside air to flow over the heat exchanger core, melting any frost accumulation. After the defrost period, the fresh air supply fan automatically returns to the normal speed and fresh outside air continues to be drawn into the building. Water from the melted frost collects in the bottom drip pans and drains out through the bottom drain connections. The defrost cycle repeats automati- cally until the air temperature rises above 27°F (-3°C).

Location

The 2500EFD is designed to be mounted outdoors, usual- ly fastened to a roof curb assembly. Special care and attention should be given to positioning the cross mem- bers of the roof curb, so that they line up exactly with the duct openings on the HRV (see pg. 7). The 2500IFD must be located in a heated space where the surrounding air temperature does not fall below freezing point. The exhaust air temperature must be above 60˚F (16˚C) for proper defrost operation.

If the air temperature is too low the defrost time may need to be increased. The unit must be mounted level (horizontal) to obtain proper drainage of water from the heat exchange cores and drip pans.The warranty will be void if these conditions are not met.

Typically, the HRV is positioned close to an outside wall or the roof to simplify the connections and keep the length of insulated ducting to a minimum.

A minimum clearance of 40 in. (1 m) on one side of the HRV is recommended to service the heat exchanger cores and the filters.

Mounting

The 2500EFD is designed to be mounted on a roof curb.

When assembling the curb, note position of cross members which provide duct support. Note access through the roof will be required.

It is also important to ensure that the perimeter of the curb is insulated, but the interior of the curb is not. This allows heat from the building to prevent freezing of the drain lines and pans.

The 2500IFD should be hung by a threaded rod type assembly which provides a cradle for the unit (see pg. 11). Note that 2X4's should sit under the unit to avoid damage to the lip of the cabinet. The HRV may also be mounted on an equipment platform provided that the drain hoses are clear and there is sufficient space for service access.

FRESH AIR

FROM OUTSIDE

FILTERS

STALE AIR

FROM INSIDE

DRAIN PANS

CORE	BLOWER
	STALE AIR
	TO OUTSIDE
	MOTORS
	FRESH AIR
	TO INSIDE
	BLOWER
P-TRAP
9