John Siegenthaler, P.E.

In last month’s column, we discussed the design and actuation of 3-way diverter valves. This month, we’ll look at several applications for these valves.

Primary/secondary piping is a way to achieve hydraulic separation by connecting multiple hydronic circuits with their own circulators to prevent interference. Using a pair of closely spaced tees is a common method to achieve this.

There are many scenarios in which flow at some location within a hydronic system has to be directed along one of two possible flow paths. When a single valve is used to create this routing, it’s called a diverter valve. In part 1, we're digging into motorized 3-way diverter valves and actuator options.

In rural upstate New York, residents harvest trees for firewood using chainsaws and hydraulic splitters. I burn about two face cords annually in my wood stove, enjoying its warmth during winter and relying on it during power outages caused by outdated utility lines.

Last month, we discussed how solid thermal energy storage, combined with an air-to-water heat pump and an electric boiler, provides a platform to leverage time-of-use electrical rates in ways that can benefit customers as well as the utility providing the electricity.

I’ve written many PM columns discussing how air-to-water and geothermal water-to-water heat pumps can be combined with hydronic delivery systems to deliver efficiency AND superior comfort. This combination is a great solution for many consumers.

There is a growing interest in adding air-to-water heat pumps to existing hydronic heating systems. While I support their use, I do not recommend replacing a perfectly good cast-iron boiler that still has a long service life.

A problem is developing with the transition to electric heating: peak demand. Learn how air-to-water heat pumps tackle seasonal needs but struggle during extreme cold, leading to reliance on electric resistance heating.

Discover the major flaws in a proposed heating system and learn about a makeover approach to eliminate the issues.

Find out about piping options for retrofitting an air-to-water heat pump into an existing hydronic system.