Onix Tubing Installation Manual

Watts Radiant: Onix Installation Manual page 13
per square foot, like a Sunroom, it
should not be zoned with a room that
only requires 10 BTUs per square foot.
The above illustration uses the occu-
pancy technique for zoning, dividing
the waking areas from the sleep-
ing areas. Zoning choices are subject
to change as the design progresses. It
is not uncommon to go back and
rearrange rooms and zones to create a
better overall design.
Step 3:
Manifold Location
Each zone will generally have one
manifold pair - a supply and a return.
Watts Radiant offers a wide range of
manifolds ranging from custom brass
manifolds, to cast brass manifolds, and
stainless steel. More information on
manifold options can be found in the
Watts Radiant product catalog.
With respect to any design, the mani-
fold location has a direct impact not
only on the aesthetics of a room, but
also on the tubing being installed.
1. Manifolds should be placed in a
location that allow them to remain
accessible, but also out of sight. In
cabinets, behind doors, and in clos-
ets are good locations. These loca-
tions allow for the use of a cover
plate or manifold box over the
manifold to keep the assembly
hidden from everyday view.
2. Manifold placement determines
the minimum tubing circuit length.
Minimum circuit equates to the dis-
tance from the manifold to the far-
thest point, taking right angles, and
back. For most residential projects,
200 ft. circuits are adequate. For
most commercial projects, 300 -
400 ft. circuits are used.
3. Locate the manifold within the
given zone. If a manifold is located
outside the zone boundary, then
twice the distance (supply and
return) to the manifold should be
added to each circuit length. For
example, if a zone calls for 180 ft.
circuits, and the manifold is moved
to a location 10 ft. away, then 20 ft.
is added to the circuit. The circuit
lengths required for this zone will
be 200 ft.
4. Manifolds should be mounted
horizontally, if possible. This
allows for easier circuit connection
to the manifold. Also, if a
vent/purge assembly (recommend-
ed) is installed on the manifolds,
they must be mounted horizontally
in order to allow the vents to work
properly without leaking.
5. Manifold sizes are based on the
zone flow rates (in gpm). The
smallest trunk size provided by
Watts Radiant is 1". For commer-
cial and snowmelt applications
Supply Max.
Pipe Size Flow Rate (typical)
3/4" . . . . . . . . . . . .4 gpm
1" . . . . . . . . . . . .10 gpm
1-1/4" . . . . . . . . . .15 gpm
1-1/2" . . . . . . . . . .22 gpm
2" . . . . . . . . . . . .45 gpm
ZONE 1
ZONE 2A
ZONE 2
Typical radiant zoning.
Zoning