Figure 1 shows the piping layout for an actual installation. It uses two boilers, fired in stages, to supply three areas of a building. One of those areas is sub-divided into three zones. The other two areas are handled by individual zone circulators. The "primary circulator" operates whenever any load circuit is on. All circulators are fixed speed. There's a partially closed ball valve at the end of the "primary loop."
Taco proudly recognized Mr. Kang Ho Lee, Chairman of Taejin Fluid Technology (TJFT), with the prestigious Dan Holohan Award at the 2026 AHR Expo. The award honors individuals who exemplify lifelong dedication to hydronic education, industry leadership, and the spirit of mentorship embodied by Dan Holohan.
In hydronic systems, the circuit usually passes through the boiler, which adds heat. When using a block heater and the boiler is off, it dissipates heat from the circuit. This heat loss must be considered when measuring the circuit's true "net" heating output.
We become comfortable with what we perceive to be best practices and believe they are also safe for all involved. Cupric oxide will always be a concern when brazing copper refrigerant line sets, so purging with nitrogen is the best way to keep your refrigerant lines clean and pristine during brazing.
