Expanded Snow Melt Specification
January 14, 2008 - SNOW 1.7
1. Slab Heating Pipe & Installation
1.1
Provide a complete floor heating system as shown on the plans and as specified.
Length of loops, pipe sizing and spacing to be determined by HeatLink® or
approved manufacturer.
1.2
Piping installed in the slab shall be HeatLink® cross-linked polyethylene (PEX)
piping installed in loops with spacing and length as per design drawings or
HeatLink® design calculations. The PEX pipe shall have one standard
dimension ratio SDR 9 and the fittings shall have a nominal size from 1/4" to
2". Only fittings recommended by the PEX pipe manufacturer are acceptable
for use with the PEX tube distribution system.
1.3
The PEX pipe shall comply with the following codes, standards and
certification for use in continuous hot water circulation systems.
1.3.1 DIN 4726 (oxygen diffusion limited to 0.1 g/m3/day at 40°C)
1.3.2 PPI – TR4 Pressure/temperature rating 100 psi at 180°F
1.3.3 ASTM F876/877
1.3.4 CSA 137.5
1.3.5 NSF-rfh
1.3.6 ICC-ES
1.3.7 UMC
1.4
For on grade projects, PEX pipe shall be placed with either HeatLink® Tracking
or tied to either a 6" x 6" wire mesh or a rebar with an even grid pattern, such as
12" x 12", 18" x 18", or 24" x 24" using plastic tie straps.
1.5
Under no circumstances shall the PEX pipe be tied with a binding wire. The
installation shall be in strict accordance with the manufacturer’s instructions. If
a PEX tube is kinked during installation, a heat gun may be used to repair the
kinked portion in accordance with the manufacturer’s recommendation.
1.6
Ensure that a minimal bending radius of 6 times the pipe diameter is
maintained: 5/8" piping = 4" radius, 3/4" piping = 5" radius. Ensure that a
minimal bending radius of 8 times the diameter is maintained: 40x3.7mm piping
= 13" radius, 50x4.6mm piping = 16" radius.
1.7
Piping to have a fully enclosed protective conduit elbow where pipes penetrate
the concrete flooring.
1.8
Provide a 300mm (12") protective sleeve where PEX pipe crosses expansion
joints.
1.9
Only fittings approved by the PEX pipe manufacturer shall be used.
1.10 Do not install PEX pipe within 6" of any gas appliance vents, or within 12" of
any recessed light fixtures.
1.11 Closely coordinate in-slab piping layout with other trades. Avoid sanitary drain
piping penetrations, electrical conduit penetrations, partition wall anchors,
furniture anchors, etc. through floor assemblies.
1.12 In all areas where other trades will be drilling, coring or anchoring other
equipment, furniture, or structures to the slab, the Contractor shall mark
locations of the PEX pipes to avoid penetration of fasteners used (i.e., Hilti,
Ramset, etc.).
1.13 If in-slab repair joints are necessary, only brass insert compression couplings as
approved by the PEX pipe manufacturer shall be used. Wrap all couplings with
PVC tape or compatible material prior to concrete pouring to prevent any
possible corrosion.
1.14 Ensure a minimum of 1/4" thick foam or "sill gasket" expansion stripping is
placed against all inner and outer walls i.e. wherever the concrete topping
comes in contact with a wall plate. In the case of "gypsum" pour, expansion
stripping is not necessary.
1.15 System to be controlled with an outdoor temperature reset controller in
conjunction with an outdoor sensor and a secondary supply water temperature
sensor. Controller to operate a fully automatic modulating a temperature mixing
device. Snow-melting control is to be provided by HeatLink® #31667 outdoor
reset controller together with a snow/ice sensor or detector (HeatLink® #30090
and 30091) that activates and controls the system based on moisture detection
and slab temperature.
2. Hydrostatic/Air Testing
2.1
Pressure test HeatLink® PEX pipes to 80 to 100 psi (hydrostatic) or 60 to 80 psi
(air test) for a minimum of 24 hours prior to and during concrete pouring, or
before any piping enclosure.
2.2
Each PEX pipe loop shall be individually filled in either test.
3. Manifold/Header
3.1
Provide factory pre-fabricated high impact plastic (PSU/PPA) or stainless steel
flow balancing manifolds for all distribution requirements. Manifold shall be
equipped with manual air vent, hose bib, temperature gauge. Supply module
with built in shut off valve and return module with manual flow regulating and
balancing valve.
3.2
Distribution manifolds shall be complete with factory designed and supplied
support brackets and end caps if so required. Manifolds shall be capable of
taking on 5/8" or 3/4" PEX pipe.
3.3
Manifold assembly temperature and pressure ratings shall meet or exceed the
following:
3.3.1 Working pressure: 87 psi (6 bar)
3.3.2 Operating Temperature: 160° F (70°C)
3.3.3 Maximum Temperature: 180° F (82°C)
3.4
All loop numbers to be clearly marked on PEX pipe wall before being
connected to manifold. Loop number to be printed and placed on each
individual module in the manifold tag slot with the identification tags provided.
Pipe loops to be identified to allow for system balancing in the future.
3.5
Manifolds to be housed in an accessible manifold housing/enclosure. Housing
to be either built on site as part of the framed wall structure or optionally a prefabricated metal access box to be provided. Doors to be hinged to allow for
unobstructed access in either case.
3.6
Manifolds to be wrapped with plastic sheets for protection from dirt, dust and/or
concrete during pouring in the course of construction.
3.7
Manifolds shall be HeatLink TwistSeal®, Stainless Steel #76000 series or
approved equal.
4. HeatLink® Snowmelt Control
4.1
Snowmelt control is a microprocessor based control that regulates precisely the
rate at which heat is transferred into a snow-melting slab. The control shall
protect the slab from being brought up to temperature too quickly. In addition,
the control shall sense the return water temperature to the heat source to avoid
thermal shocks.
4.2
The ice/snow detector shall signal the controller to the presence of snow or ice
at specific selected surface temperature and moisture conditions. As well as
reading temperatures, the detector/sensor shall detect surface water and not be
installed in an area where excess or standing water occurs.
4.3
In the presence of a possible power outage or fault in the detector under freezing
weather conditions, the controller shall activate a warning contact.
5. System Start-Up
5.1
Thoroughly clean, degrease and flush the new system before antifreeze solution
is added. System cleaning shall be in accordance with the manufacturers’
recommendations
5.2
Add to slab heating system no less than 50% glycol/water mixture for freeze
protection and system corrosion inhibitor, i.e. Dowfrost, Ucartherm or
equivalent.
5.3
Test corrosion and/or antifreeze solution for protection level and maintain
records in a manual to keep track of water quality control.
6. Testing, Protection, Balancing And Warranties
6.1
Contractor shall be responsible for ensuring all necessary adjustments to floor
heating equipment and controls, and that the entire system is fully tested,
balanced and operating as per specification.
6.2
All systems not using a water make-up shall be provided with low water cut•off
protecting all mechanical components including boiler, pumps, etc.
6.3
If applicable, all maintenance data and operation instructions on system
controller shall be provided and kept on site complete with a copy of piping
layout. Data shall be neatly assembled and placed in a protective binder.
6.4
All PEX pipes shall carry a 25 year guarantee from the manufacturer,
complete with a 10 year third party consequential coverage including damage and
expenses incurred. Refer to the HeatLink® warranty certificate.