Install Hot Water Radiant Heat

There are several heating systems used in heating a commercial building. But the hot water radiant heat is the efficient, quiet and comfortable method to heat a commercial building or even your homes. The method uses pipes to channel hot water through the tubes installed in the floor which are often concrete slabs. When the floor warms it simply radiates heat into the room.

The water is basically heated by a solar water heater, a boiler, a solar water heater or even a hot water heater. The system provides a small pump the pushes the heated water through each closed loop on the floors. To control each heating zone, valves and thermostats are installed on every heating zone.

Standard components of the hot water heating system

• Radiant heat tubing (cross-linked polyethylene tubing)
• Tubing fittings
• Zip ties or tubing clips
• Boiler
• Boiler taps
• Ball valves
• Manifolds
• Copper pipe and fittings
• Expansion tank
• Automatic vent valve
• Pressure relief valve
• Recirculation pump and expansion tank
• Switching relay
• Control valves
• Thermostats
• Control module
• 24-volt transformer
• Charging pump

The procedure

1. The Standard Tubing Installation

Draw a zoning diagram for your project. Then plan the order of your work according to your zoning diagram. For each zone, draw a piping schematic diagram. Fundamentally, water is hottest as it leaves the heating supply and is coolest on its return. Basing on this theory, begin each zone along the exterior walls of the room which loses the most heat.

2. Always leave extra length at the beginning and end of your tubes to connect to the manifold. Lay the tubing 6 inches apart or 6 inches spacing between runs. To ensure you have no cold spots, keep the spacing even. Follow your piping schematic diagram and unroll the piping carefully. To fix the tubing, you can clip to the under slab insulation or tie the tubing to reinforcing steel in the slab using zip ties. Never bend or kink the tubing at sharp angles.

3. To protect your pipes from concrete, tape the ends of the pipe well. Then you can pour the concrete slab.

4. Connecting to the Hot Water Supply

Begin connecting the supply line and the return line from each zone to the supply manifolds and the return manifolds. Then you can install the zone control valves on the return lines. You can now connect the supply manifold to the boiler on its supply side. The return line on the other hand will now be connected to an expansion tank and then the recirculation pump. The recirculation pump is also connected to the boiler on its return side.

5. Now you have to install an automatic vent valve most likely at the highest point of your piping system. A venting valve is normally used to help release gases and steam that can cause problems in the system.

For safety purposes, also install a 30 psi automatic pressure relief valve in the system. The relief valve is used to control or limit the pressure in the system.

6. Then you can begin installing at least two boiler taps with a ball control valve in between them. Choose a convenient point of their location in the piping system. These boiler taps are used to charge the system with propylene glycol and distilled water mix for circulation. The propylene glycol provides heat resistance to the water mix.

7. Using the manufacturer’s wiring diagrams you can now hook up the electronic controls for the system.

8. Start Charging the System

Begin attaching rubber hoses to each boiler tap. Close the ball valve between the boiler taps. Then attach one hose to the output side of the charging pump. Attach the other hose to a 5-gallon pail. Using a third hose, attach one end of to the inlet of the charge pump and the other end into the 5-gallon pail. Fill the pail with distilled water mixed with propylene glycol.

9. Then open both taps and run the pump. Add fluid to the pail continuously keeping both hoses covered. Continue running the pump until you see no bubbles in the bucket.

10. The close the boiler tap that is connected to the 5-gallon pail. Let the charging system increase the pressure up to 15 to 20 psi. Then close the second boiler tap and turn off the charging pump. Then you can now open the ball valve between the boiler taps.

11. The mixture ratio of propylene glycol to distilled water can vary according to climate. The propylene glycol prevents the water in your floor from freezing if there in cases of power failure.

12. Remember to manually set to open position control valves while charging the system.

13. Lastly, check your local building codes if it requires certified electricians and plumbers to install your system.

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