Installation Concrete Slab; Service And Access Clearance; Clearance To Combustibles; Burner/Blower Section - Greenheck VSU Installation, Operation And Maintenance Manual

Installation
Concrete Slab
The first step in unit installation is to pour a concrete
slab capable of holding the unit weight as a base. The
slab should have a proper gravel drainage bed.
Concrete Slab Dimensions
Housing Size A
20 64
30 77
40 78
50 87
All dimensions are shown in inches.
If optional service platform is included, a minimum of
42 inches must be added to Dimension B.
Building Wall
Approx. Stand Feet Locations
Concrete Slab
D
A
12
12
Concrete Slab and Unit Footprint

Service and Access Clearance

The slab should be positioned to allow 3 feet of
clearance on the control end of the unit and 2 feet of
clearance on the other three sides. Housing size 50
requires 3 feet of clearance on both ends because of
filters access. Note that the concrete forms a 1 foot
wide apron on all four sides of the unit unless a 42 in.
extension is added to the control end of the unit.

Clearance to Combustibles

Floor
0 in.
Insulated/
Units
(0 mm)
Non Insulated 0 in.
Units
(0 mm)
Clearance to combustibles is defined as the minimum distance required
between the heater and adjacent combustible surfaces to ensure the
adjacent surface's temperature does not exceed 90 degrees above the
ambient temperature.
®
B C D
64 42 37
76 42 49
135 42 51
180 42 60
NOTE
E
B C
Top Sides Ends
0 in. 0 in. 0 in.
(0 mm) (0 mm) (0 mm)
6 in. 6 in. 6 in.
(152.4 mm) (152.4 mm) (152.4 mm)

Burner/Blower Section

Use a crane and a spreader bar hooked to the factory
lifting lugs (shown below) to lift and center the unit onto
the filter stand section. The sections should be caulked
together.
E
37
49
108
153

Install Ductwork

This table shows the duct sizes and straight lengths
recommended for optimal performance (AMCA
Publication 201-90). Using duct sizes less than
recommended will affect fan performance. Good
duct installation practices should be followed for the
remaining ductwork.
Recommended Supply Ductwork Sizes
VSU
Blower Size
108
109
110
112
115
118
120
218
220
225
230
Spreader Bar
Duct Size Straight Duct Length
(in.) (in.)
10x13 32
14x13 38
16x14 42
18x16 48
19x16 49
24x22 64
28x28 79
68x24 114
68x26 118
104x37 175
104x37 203
Model VSU Make-Up Air 7