Several years ago, I had the opportunity of visiting the Mostra Convegno Expocomfort show in Milan, Italy. It ranks right up there with the famous ISH show in Frankfurt, Germany, as a “bucket list” event for those who are passionate about hydronic heating and plumbing.

Last month, we discussed the role of buffer tanks in combination with air-to-water and water-to-water heat pumps that operate as “on/off” devices. The buffer tank allows the heat pump to operate with reasonably long cycles (e.g., it prevents short cycling) when the hydronic distribution system is heavily zoned, and thus subject to “micro-loading” at times. We also discussed how some buffer tanks can do double duty as both buffers for space heating loads and domestic water heaters. The key concept was to turn the heat pump on and off based on changes in the buffer tank temperatures and not based on thermostats calling for heat.

More and more hydronic heating and cooling systems are being designed around air-to-water and water-to-water (geothermal) heat pumps. When the heating distribution system is extensively zoned, a buffer tank is typically installed between the heat pump and that distribution system.

Government planners, taking their queues from politicians and advocacy organizations, have steered the future of energy supply away from fossil fuels and toward renewably-sourced electricity. It’s happening on every level from the feds right down to local city councils.

Many legacy hydronic heating systems use a fossil fuel boiler to supply fin-tube baseboard heat emitters in some areas of a building and lower-temperature radiant panels in other areas. 

Water-to-water heat pumps, supplied from geothermal earth loops, represent a growing sector of the hydronic heat source market. Most current-generation models can produce water temperatures up to about 125° F, perhaps a little higher if you’re willing to push the compressor operating envelope.

 All boilers that burn hydrocarbon fuels such as natural gas, propane, oil or wood produce water vapor as a byproduct of combustion.

I’ve written it before and I’ll write it again — panel radiators are one of my favorite hydronic heat emitters. I base this sentiment on several benefits. Here are a few to consider…

The choice between ∆T and ∆P operation of a circulator has, at times, been the subject of rather “heated” debates. It’s almost as if a few Yankee fans are disputing superior pitching or batting performance with a few Red Sox fans. There appears to be some strong opinions involved.