Panel radiators operated at low water temperatures, and with minimal fins attached to the rear of the water plate, can emit upwards of 50% of their total output as radiant heat.
AHR Expo 2026 made it clear that hybrid systems are no longer an emerging idea; they are the answer to the ongoing balancing act of meeting decarbonization goals while remaining realistic about the grid's capacity for electrification. Manufacturers emphasized systems that combine electric technologies, gas-fired equipment, and advanced controls.
Measuring the flow rate through a circuit has always been more of a challenge compared to measuring temperatures. Very few circuits are equipped with permanently installed flow meters.
Can you speculate why heat delivery in zone 3 was insufficient before the helper pump? How could the piping system be improved, considering the wasted length of PEX-AL-PEX tubing from the manifolds to the floor panels in figure 2?
For boilers operating on natural gas or propane, flue gas condensation begins at inlet water temperatures below about 130 ºF. Boilers operating on low sulfur #2 fuel oil have lower dewpoint temperatures in the range of 110 ºF.
The homerun system is a simple technique for connecting multiple heat emitters using two runs of small flexible tubing (such as PEX) for supply and return. In North America, the standard size is 1/2-inch, but 3/8-inch tubing can be used with proper design and compatible fittings.
An owner, who has never been satisfied with the performance of his heating system, decides that the boiler must be the root cause of all the performance issues. Not wanting to spend any more than necessary, he makes several calls looking for the lowest boiler replacement price.