Snowmelt system
A snowmelt system may extend the life of the concrete, asphalt or under pavers by eliminating the use of salts or other de-icing chemicals, and physical damage from winter service vehicles.
These types of devices ensure the system is only active during useful periods and reduce energy waste.
Electric snowmelt systems are composed of three basic components: heating cable, a control unit and an activation device.
The heating cable is built to withstand harsh conditions to make it suitable for outdoor usage.
The cable should be listed to UL standards by a Nationally Recognized Testing Laboratory and many consist of a single or dual conductor with a protective coating and/or insulation.
In this context, a special grooving machine was envisioned to make shallow channels in the asphalt for cradling each ribbon.
Thus, the system survivability is guaranteed, with all ribbons protected against the maneuvering of trucks, paving equipment, and heavy rollers.
Subsequently, the method was demonstrated through the full-scale construction of a heated road that included installing ribbons in-between asphalt concrete lifts.
For this purpose, the protective ribbon channels were grooved with a customized milling machine.The heating element in a hydronic system is a closed-loop tubing or modular thermapanel system made of a flexible polymer or synthetic rubber that circulates a mixture of hot water and propylene glycol (antifreeze).
The use of high temperature fluid entering a very cold slab will create stress cracks and possible spalling of the concrete surface.
An alternative to tube based systems is pre-insulated, HDPE modular heat exchange thermal panel units.
Insulated modular thermapanel systems do not require re-mesh or rebar and are laid out in pre-connected rows onto the compacted sub-base.
Pre-insulated modular thermapanel systems can be laid directly on bedrock or a structural concrete base.
Modular snowmelt systems can also be used to collect solar thermal energy from the pavement on warm days for the heating of pools and domestic or industrial purposes.
They may also be utilized to cool the pavement surface, particularly around swimming pools or on pedestal mounted rooftop paver terraces which get very hot due to the paver being uncoupled from the building thus creating a solar battery which in turn increases the urban heat island effect in the immediate vicinity.
The American Society of Heating, Refrigerating and Air-Conditioning Engineers has standards intended to achieve satisfactory results and to minimize energy consumption from over-sizing or over-designing a system.
Systems are typically designed to produce 70–170 BTU per square foot hour using ASHRAE guidelines by region.
The time to melt snow from a surface varies by storm and how much power the system is designed to produce.
Installing a snowmelt system under brick pavers is achieved by placing the heating cables on the base surface over 1/2" of sand.
These plug into a water-resistant electrical outlet, and can be laid on walkways, driveways, stairways, wheelchair ramps, and loading docks.
