Lochinvar 399 - Manual (Page 18)

Hydronic Heating Boilers and
Domestic Water Heaters
18
INSTALLATION Continued
The Vertical DirectAire™ vent system requires you to install
two vent pipes directly to the unit; one vertical pipe with a
rooftop termination for the flue products and one pipe for
combustion air. For this venting option, you must purchase the
DV box adapter from the appliance manufacturer. The DV box
attaches to the air inlet of the unit. The pipe for combustion air
attaches to the DV box.
You can terminate the combustion air pipe either horizontally
with a sidewall air inlet or vertically with a rooftop air inlet.
The installed length of air inlet pipe from the unit to the outside air
inlet cap must not exceed 50 equivalent feet (15.2m).
FIG. 18 Vertical DirectAire Installation with Sidewall
Combustion Air Inlet
FIG. 19 Air Inlet Cap for Sidewall Termination
FIG. 20 Vertical DirectAire Installation with Roof Top
Combustion Air Inlet
Vent Kits
For single unit installations with sidewall air inlet, (see
FIG. 18) you must order the sidewall air inlet kit from the
appliance manufacturer. The part number for each SVK kit is
listed by unit size in TABLE–D.
For single unit installations with rooftop air inlet (see FIG. 20),
you must order the rooftop air inlet kit from the appliance
manufacturer. The part number for each VDK kit is listed by
unit size in TABLE-D. Purchase the flue pipe, rooftop flue
termination, and air inlet pipe locally.
There is no vent kit for combined air supply systems for
multiple units. Make sure the air inlet cap is properly sized.
You must purchase this cap locally.
Venting of Flue Products
For venting flue products vertically to the outdoors, follow all
requirements in the installation instructions for conventional
venting in this manual.
Follow all clearance requirements in Vertical Vent Termination
Clearances and Location, page 11.
A barometric damper is not required in the flue on Vertical
DirectAire™ installations if the draft is within the negative
0.02 to 0.08 inches w.c. required for proper operation. If the
draft exceeds this range, install a barometric damper.
™
ƽ
WARNING: Only use a sidewall air inlet
cap supplied by the appliance
manufacturer or a rooftop air inlet cap
supplied by the vent manufacturer. Using
any other air inlet cap for single unit
installations or using a common air inlet
cap for multiple units with insufficient free
area and/or protections from wind and
weather may result in operational problems
and the spillage of flue products. Spillage
of flue products can cause personal injury
or death due to carbon monoxide
poisoning.
12"
3'