Thornhill Snow Melt - Phase 2
Taking on the mechanical room for this snow melt project.
For this snow melt, the PEX tubing is ready laid and the concrete encasing it has cured. Bringing in the supply and return lines into the garage is the next critical part of this project. We core the hole to feed the PEX lines into the garage. We then mount the plywood, checker board, manifolds, boiler, mechanical components and lastly wire up the electrical.
Tes cores the holes to bring in the supply and return lines from the driveway into the garage where we will setup the equipment.
Two 4″ holes are needed for this home. We use an Uponor 1-1/4″ x 5 loop manifold. PEX lines for the driveway are always 3/4″ diameter. The extra PEX is for the Tekmar snow melt sensor. It will be strategically positioned between 2 loops to ensure accurate readings.
We insulate the PEX lines on the supply side but not the return. Colder return temperatures maximize the efficiency of our condensing NTI 175 K BTU TFT boiler.
The extra tube coming out of the left side will house the snow melt sensor wire. Tubing expands and contracts with temperature fluctuations. We sleeve the PEX passing through the concrete to prevent it from crumbling.
A pressure test confirms the manifold is not leaking and the lines are intact. The 2 x 4 holds the PEX in place for the concrete fill. We take pride in our work!
We mount 3/4″ plywood to the garage wall and dress it with checker board.
Typically we allocate 150 BTU’s per square ft of snow melt. This customer will be installing in floor heating when they renovate the main floor. Hence, we oversized the boiler to allow for future expansion plans. Modulating boilers regulate the output to meet the call for heat of the system.
After we mount the boiler, we pick a good spot for the Schuller Hydronic separator. This serves multiple purposes. There is a fine screen inside that filters out the air bubbles and released them through the automatic air vent through the top. The 2nd function it serves is to mix the return water with a little of the supply. This prevents thermal shock on the boiler.
NTI boilers do not have a built in circulator so we add one on the return side to keep the ‘primary loop’ cycling.
A properly sized non potable expansion tank will buffer our pressure from tripping the pressure relief valve on the boiler. The AXIOM digital automatic glycol feeder will top up any fluid that manages to escape the system. When the system runs, the air works itself out and that space is replaced by glycol.
We add a condensate neutralizer/pump to redirect the products of combustion to a proper drain in the house.
The glycol supply and return for this manifold route from the top, around a portion of the garage and into our manifold. Almost ready for electrical.
Next we add the gas and venting. A 1-1/4″ gas line supplies this unit with more than enough gas.
Electrical, gas and venting are complete. Ready to hand off another snow melt to this excited customer.
We follow up visit amidst a major snow storm confirms this system is up and running! 25 cm’s and keeping up.