How to Design for Heating With Hot Hydronic Water

Familiarize yourself with the basic components of hydronic systems. The heating unit must have the proper size to meet the heat-load requirements for the size of the house. One or more circulation pumps moves water through the system. The manifold connects to tubing, which sends hot water to the zones and returns cool water to the heating unit. A mixing valve blends hot water from the system and cool water, returning to the system to control water temperature in the zones. Sensors and thermostats allow for regulation of zone temperatures.

Gather the information for the loop spacing and the length for each zone or room -- record the length and width of each room. A loop consists of a continuous piece of tubing for sending hot water and returning cool water. These numbers multiplied together compute the square footage for a particular room. Use the data to determine the spacing and length of the loops. The proper calculations help ensure an efficient heating system.

Figure out the best way to run the tubing for the zones. Install tubing in concrete slab before pouring the concrete for new construction. Run tubing underneath the subfloor or on top of the subfloor for remodeling or floors already in place. Installation on top of a subfloor requires a thin layer of concrete to cover the tubing and the installation of a floor covering. The best method for installing tubing depends on the circumstances.

Draw a layout of the project on graph paper. Determine the number of zones. Use the measuring tape to obtain the distance of the supply connection from the manifold to the zone and back to the manifold. Larger rooms may require multiple zones. Each zone requires its own zone valve, which connects to the manifold. Include the length of the copper supply and return pipes from the boiler to the tubing for each zone.

Determine if the system will have one circulator pump for each zone or only one master pump. One circulator pump for the entire system necessitates the installation of a "tee" for each zone. This method is less expensive for projects with multiple zones. Decide the connection points in the copper lines for inserting "tees" for the air vents. Air vents allow air to escape from the system. Make a decision for the installation of the thermostat(s) and floor sensors.

Discuss the project with the supplier. The supplier has the technical knowledge to answer questions and help make important decisions concerning the system's design and installation. This person can take the information gathered and help determine heat loss or at what points in the layout design to install certain components. This helps minimize materials usage, such as copper pipe and tubing, while installing an efficient hydronic heating system.