Field Controls CAS-2A User Manual

COMBUSTION AIR SYSTEM

A

Model: CAS-2A

4” VRV

AIR BOOT™

4” IAH HOOD

This product is designed for use on the following burners, for the purpose of routing
combustion air directly to the burner, with the added safety feature of the vacuum relief valve.
NOTE: For burner inputs up to 2.0 GPH at 100 PSI input pressure or equivalent.

“The Air Boot™ model CAS-2A is for use only on the designated burner(s) as described in
these instructions only when the specific burner includes this Air Boot™ when shipped from
the burner manufacturer or where the burner instructions specifically reference the models
CAS-2A Air Boot™ as an optional air intake system.”

ERO MODELS

F-AFC HF-AFC
HF-US SV SERIES

ITEMS INCLUDED IN KIT:

1 - Air Boot™
1 - 4” VRV
1 - 4” IAH Hood
1 - Burner Coupling Set
2 - Mounting Bolts

INSTALLER SUPPLIED ITEMS:

Duct Piping and Elbows
90° Elbows;

¼ “ NPT Female x ¼” NPT
Male for routing oil line

THE PURPOSE OF THE VRV

The Vacuum Relief Valve is a safety device to guard against combustion problems associated with directly
connecting oil burners to the outside. Typical problems can be caused by blockage of the intake termination,
icing up of the duct work and effects of leeward side wind effects on a building.

VRV OPERATION

The VRV gate operates on changes in the vacuum pressure generated by the inlet to the oil burner. The VRV
gate will remain closed during normal burner operation. During an abnormal operation (i.e., blockage of the
intake or change in external building pressures) an increased negative pressure on the intake of the burner
causes a reduction in burner air flow. Under this condition, the VRV gate opens, stabilizing and maintaining
proper air flow to the burner. The VRV gate closes again once the abnormal condition is corrected.

INSTALLATION

1. Remove the oil pump and air bands from the
burner housing. Position the Air Boot™ over the
burner housing on the intake. Align the holes in the
Air Boot™ with the holes in the housing and re­attach the oil pump. (See Figure 1) NOTE: Replace
pump coupling with the coupling supplied with kit.
Mount VRV tee assembly or 90° elbow onto the Air
Boot™ intake. Fasten using three (3) sheet metal
screws on all joints. (See Figure 2)

Figure 1

Figure 2

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