All closed-loop hydronic systems require an air space to absorb the increased volume of water as it warms during system operation. In most hydronic systems, this task is handled by an expansion tank. In most modern hydronic systems, it’s handled by a diaphragm-type expansion tank.

Last fall, I taught my first online course dealing with designing hydronic heating systems. The course was titled “Mastering Hydronic System Design.” It was a collaborative effort between HeatSpring Learning Institute, BNP Media’s CE Campus and myself.

In past columns, we’ve discussed geothermal water-to-water heat pumps and air-to-water heat pumps via hydronic heat sources. Both can be a great match to low-temperature hydronic distribution systems.

After completing a hydronic installation, especially one that’s taken you a few days longer than expected, do you ever ponder that there is just too much “stuff” in some of these systems?

The market for wood-gasification boilers is growing in North America. Most are used in rural areas where natural gas in not available, and thus the cost of firewood is often very competitive against the alternatives of No. 2 fuel oil or propane.

Differences exist between rules of thumb and precise calculations.

 The following formula has been around the North American hydronics industry for a long time:  

 North American hydronic professionals can now choose from dozens of modulating/condensing (mod/con) boilers. Many are designed for wall-mounting. Those who design these boilers strive for small enclosures and low weight.  

 For decades, well-designed and -installed hydronic heating systems have earned a reputation for superior comfort. Still, potential customers who understand and desire the benefits of hydronic heating often ask, “But how does this system provide cooling?”  

Interest in biomass heating systems continues to rise, especially in rural areas of the United States and Canada. Although plenty of devices are available that burn wood to heat water, the state-of-the-art device is a wood-gasification boiler.