Onix Tubing Installation Manual

page 12 Watts Radiant: Onix Installation Manual
Carpet and Pad Flooring
Carpet floor coverings help prevent
floors from feeling cold because they
have a higher R-value, or resistance to
heat transfer, than any other floor cov-
ering. Carpet pads reduce energy
transfer while providing some support
and cushion to those standing.
With respect to a radiant floor heating
system, a carpet and pad floor cover-
ing is the most difficult to heat
through. In general, the ideal floor
covering would have an R-value of 2
or less. In most cases, since we are
using a floor heating system, a thinner
pad should be used. Try to keep the
pad thickness below 1/2".
Step 2:
Radiant Zoning
Zoning is a way of controlling how the
heat is delivered to a given area. The
more zones there are, the higher the
control level. There is no rule to the
amount of zones needed for a project.
There can be as many zones as there
are rooms and as few zones as there
are levels (minimum one zone per
floor level).
There are several ways to zone a proj-
ect.
1. Zoned by Floor Coverings:
Different floor coverings transfer
energy at different rates, resulting in
varying supply water temperatures.
A kitchen, with a tile floor may only
need 100¡F supply water, while the
family room right next to it with a
carpet floor covering may require
140¡F supply water. If these two
rooms were placed on the same
zone, there may be control and com-
fort problems.
2. Zoned by Occupancy:
Different areas of a home or busi-
ness will be used during different
times of the day or for different
activities. Bedroom or warehouse
areas tend to be kept at a lower ther-
mostat setting while the rest of a
building will tend to be kept
warmer.
3. Zoned by Construction:
There are various construction
details present in almost every
project. For example, it is difficult
to place a room with a slab floor on
the same zone as a room with a
frame floor. Likewise, it is a good
idea not to zone multiple levels of a
project on a single zone. Tubing is
not easily installed from one level to
the next and heat losses/gains can be
dramatically different from floor to
floor. Other construction concerns
might be varying joist directions or
expansion joint locations.
4. Zoned by Mechanical
Considerations:
Mechanical issues tend to relate to
the required supply water tempera-
ture or heat load required in a given
area.
Typically rooms can be grouped in the
same zone if the supply water temper-
ature does not cause the floor surface
temperature to exceed 85¡F. For this
reason, rarely is a carpeted room
zoned with a tiled room.
Rooms with similar heating intensities
(BTUs per square foot) can be zoned
together, as well. If a room has a
greatly exaggerated load of 50 BTU
Carpet Type Thickness (in) R-Value
Level Loop . . . . . . . . . . . . . . . . . . . . . ..26 . . . . . . . . . . . . . .0.64
Berber . . . . . . . . . . . . . . . . . . . . . . . . ..41 . . . . . . . . . . . . . .0.83
High/Low Loop . . . . . . . . . . . . . . . . . . ..42 . . . . . . . . . . . . . .0.86
Berber . . . . . . . . . . . . . . . . . . . . . . . . ..42 . . . . . . . . . . . . . .0.96
Berber . . . . . . . . . . . . . . . . . . . . . . . . ..48 . . . . . . . . . . . . . . .1.0
Frise . . . . . . . . . . . . . . . . . . . . . . . . ..42 . . . . . . . . . . . . . . .1.1
Saxony . . . . . . . . . . . . . . . . . . . . . . . . ..41 . . . . . . . . . . . . . .1.10
Saxony . . . . . . . . . . . . . . . . . . . . . . . . ..44 . . . . . . . . . . . . . .1.15
Saxony . . . . . . . . . . . . . . . . . . . . . . . . ..50 . . . . . . . . . . . . . .1.25
Saxony . . . . . . . . . . . . . . . . . . . . . . . . ..55 . . . . . . . . . . . . . .1.32
Cushion Thickness (in) R-Value
Slab Rubber . . . . . . . . . . . . . . . . . . . . ..23 . . . . . . . . . . . . . .0.62
Waffled Sponge Rubber . . . . . . . . . . ..43 . . . . . . . . . . . . . .0.78
Prime Urethane . . . . . . . . . . . . . . . . . ..40 . . . . . . . . . . . . . .1.61
Hair & Jute Coated . . . . . . . . . . . . . . ..44 . . . . . . . . . . . . . .1.71
Bonded Urethane . . . . . . . . . . . . . . . ..50 . . . . . . . . . . . . . .2.09
Carpet and Pad Combined Thickness (in) Total R-Value
Level Loop and
Textured Rubber . . . . . . . . . . . . . . .0.36 . . . . . . . . . . . . . .1.04
Level Loop and Froth . . . . . . . . . . . . .0.25 . . . . . . . . . . . . . .1.23
Berber and Textured Rubber . . . . . . .0.36 . . . . . . . . . . . . . .1.36
Berber and Froth . . . . . . . . . . . . . . . .0.25 . . . . . . . . . . . . . .4.54
Saxony and Textured Rubber . . . . . . .0.36 . . . . . . . . . . . . . .1.62
Level Loop and
Bonded Urethane . . . . . . . . . . . . . .0.32 . . . . . . . . . . . . . .1.67
Level Loop and
Synthetic Fiber . . . . . . . . . . . . . . . .0.33 . . . . . . . . . . . . . .1.67
Saxony and Froth . . . . . . . . . . . . . . . .0.25 . . . . . . . . . . . . . .1.83
Level Loop and
Grafted Prime . . . . . . . . . . . . . . . . .0.36 . . . . . . . . . . . . . .1.88
Berber and Synthetic Fiber . . . . . . . . .0.33 . . . . . . . . . . . . . .1.98
Berber and Bonded Urethane . . . . . .0.32 . . . . . . . . . . . . . .2.01
Subfloor
Carpet Pad
Carpet
Typical carpet and pad installation sequence over
a frame floor.
Floor Coverings