Welcome to Warm Floor Comfort!
Welcome to Warm Floor Comfort!
Sizing a Radiant Heat Manifold
In order to select the correct size of the radiant heat manifold, one needs to match the complete number of the PEX tubing circuits with branch size of a manifold. Some general practices of installation for radiant heat systems are given below:5/8" PEX tubing per circuit with 400-500ft
1/2" PEX tubing per circuit with 300-350ft
3/8" PEX tubing per circuit with 200-250ft
In Snowbelt applications:
5/8 PEX" tubing per circuit with 250ft
3/4 PEX" tubing per circuit with 300ft
For example if 900square feet area is installed with ½ PEX tubing at 9 on centre, it will therefore require approx 1200 feet of ½ of PEX tubing. After obtaining this number, it needs to be divided by the recommended length pc (per circuit) i.e. 1200/300 comes out to be 4. Decimal number can be rounded off to nearest number. The number obtained indicates the branch of the radiant heat manifold (set). The length of the tubing can be divided by number of branches as one can receive the average tubing run pc (per circuit) i.e. 1200/4=300ft.
The system would give the best performance if the radiant system is installed properly. Return manifold is the radiant manifold with the balancing value and is placed on the top and the other one with the flow indicators is the supply manifold and it should be placed in the bottom.
The system of mounting offsets, the radiant manifolds from walls. It gives a convenient access easier tubing installation and maintenance. Flow indicators can be used to serve related purpose of secondary valves. These valves can easily be adjusted to either decrease or increase the flow of water. The shut off ball valves by default are set to 180 degree straight. One can also purchase 90 degrees angle to improve the manifold.
The balancing valves which are manual and which are on return of radiant heat manifold allows adjusting the flow of water through the selected branch which can vary from 0% to 100%. Radiant manifold services the several zones of the room. It is also difficult to have almost all the circuits of the same length. The flow in the manifolds branches can be adjusted so that the every circuit gets the correct amount of hot water supply.
Radiant heat actuators can be installed in order to control the flow of hot water for every branch automatically. Actuators need not to be installed if the manifold is serving the single zone (i.e. a warehouse, a large room or a single garage). For this, single valve can be installed.
One can also install the radiant heat manifold upside down and PEX tubing to be pointed upwards. This set up remains convenient when the manifold is allocated in basement and the floor above is heated. In this case, air vents needs to remain closed and a separate device can be installed for air elimination.