As universally accepted as 12-inch spacing of radiant slab tubing is, engineers should still ask if situations exist where wider tube spacing is feasible.
John Siegenthaler looks at the basics of selecting a tube size for a given heat transport requirement and estimating the head loss of a closed loop series circuit.
Although hydronic radiant floor heating can be incorporated into many types of buildings, it's often a "perfect match" for garage-type buildings with bare concrete slab-on-grade floors.
The classic sizing procedure for a diaphragm-type expansion tank compares the volume of the system's fluid when the system is at it highest temperature to the fluid volume when the system is first filled.
John Siegenthaler's been designing hydronic heating systems for 25 years, and he still comes across little nuances that when ignored can bring a system that is 99.9% correctly designed and installed to a virtual standstill.
Although not specifically intended as heat emitters, the copper tubing connecting the components of many hydronic systems certainly does release heat to its surroundings, compromising the system's ability to deliver heat precisely where and when it's needed.
In low-temperature radiant heating and snowmelting applications, the two most common mixing device options are 4-way motorized mixing valves and variable speed injection pumping.