Barometric Draft Regulator; Waterside Flow - Viessmann Vitorond 100 VR1 Series Installation And Service Instructions Manual

Vitorond 100, VR1-22 to -33 Installation and Service

Barometric Draft Regulator

Waterside Flow

A VR1-22 to -33
When a barometric draft regulator is used, adjust the
barometric draft regulator such that the over-fire draft
is 0.00 to +0.01 "w.c., while the breech draft is
approximately -0.02 "w.c.
During operation of the burner, the barometric draft
regulator installed in the vent system must move freely.
General
The schematics on the following pages are to be seen
as guidelines only. They further do not display all system
varieties, safety devices, or concepts possible. Specific
system layouts may be further discussed with the local
Viessmann sales representative office.
Clearances
A minimum of 2" circumferential clearance from non-
insulated hot water pipes to combustible construction
must be maintained. In cases where the pipes are
insulated with pipe insulation of appropriate and
sufficient thickness and insulation values, the above
clearance may be reduced to 0".
Flow rates
The relationship between boiler flow rate and temperature
rise is according to the formula:
Boiler output (Btu/h) = 500 x flow (USGPM) x Rise (°F)
The following chart lists typical flow rates for the
Vitorond boiler:
Boiler model No.
20° F rise USGPM
(m3/h)
30° F rise USGPM
(m3/h)
Start-up
VR1-22 VR1-27 VR1-33
8 9.2 12.2
(1.8) (2.1) (2.8)
5.3 6.1
(1.2) (1.4) (1.8)
8.1
49