Onix Tubing Installation Manual

This is not to say insulation should not
be used on a snowmelt system. Areas
that need a faster response or are more
hazardous will benefit from insulation.
Stairs, handicap access ramps and
sidewalks are a few areas which may
benefit from insulation.
If insulation is to be used, a non-foil
faced, high-density, extruded poly-
styrene (such as Dow
¤
Blue Board
¤
)
should be used.
The use of a foil-faced insulation is
not required or recommended when
insulating a snowmelt slab. Foil-faced
insulation are used when an air gap is
maintained between the tubing and the
insulating member. In the case of a
snowmelt slab or brick paver applica-
tion the tubing is completely encapsu-
lated in the bedding material, eliminat-
ing any air gap. In addition, concrete
will tend to degrade exposed foil over
time.
Caution: Watts Radiant does not
advise the use of Bubble-type insula-
tion under a slab application until
more research has been done and
performance has been verified. If
needed or specified by a structural
professional, use only extruded
polystyrene, such as Dow
¤
Blueboard
¤
or equivilant. Density
and thickness should be specified
by a professional.
Control Joints
Concrete slabs will expand and
contract due to thermal changes. To
prevent damage to the slab, expansion
joints are used to control this move-
ment. In some cases cut joints are used
to control and direct cracking. Make
sure the tubing is protected according
to the requirements of the control
joint.
Design Parameters
For proper snowmelt design it is
important know the type and thickness
of each layer used. As these layers
increase or change, variances in the
snowmelting load may result. Concrete
is a very conductive material, allowing
for a wider spread in heat transfer
throughout the mass. Brick pavers do
not have the same conduction rate and
will require specific design considera-
tions. It is important all layers of a
snowmelt system are modeled correct-
ly with the use of Watts Radiant s
RadiantWorks design software.
Onix Spacing
Most snowmelt systems will use
9"—12" tube spacing with some areas,
such as steps or in front of door open-
ings, installed on 6" centers.
Tools and Materials
Required
It is a good idea to have all materials
present and in good working order
before beginning an installation. The
following is a list of the most common
items needed for a typical snowmelt
installation.
1. RadiantWorks Reports.
These reports help ensure the proper
amount of tubing is installed in each
area, along with the correct manifold
size.
2. Onix tubing and corresponding
Onix Clamps.
Each Onix TorqueTite clamp will
require an in.-lb. torque wrench for
Onix routed below expansion joint into subgrade.
Radiant Slab
Radiant Slab
Expansion Joint
Onix
Rewire / Rebar
Protective Sleeve
Subgrade / Gravel
Expansion Joint
Onix
Rewire / Rebar
Subgrade / Gravel
Onix sleeved at expansion joint with foam insulation or PVC conduit.
min. 6”
min. 2”
Caution: Do not exceed
the minimum bend
radius of the tubing.
min. 2”
min. 6”
Snowmelt
Watts Radiant: Onix Installation Manual page 51