n Hydronics

Table provided by Caleffi one. Immediately out of the gate, two boilers give you redundancy and no fear of leaving a building completely without heat.

A few years ago, I worked on an apartment facility project. The boiler we took out was an old 500,000 btu/h boiler. We replaced it with two boilers that could meet the required capacity. By doing this, we not only gave them redundancy but we also increased the turndown ratio. Now in the shoulder seasons, we can lower our firing rate to as low as 10,000 btu/h. While in the dead of winter, we utilise the full power of both boilers.

Continued from page “23” high-efficiency air separator, and I felt like I had been punched in the gut. I learned more in an hour talking to Bob then in five years of working in the field.

We sometimes wrongly assume that when we commission a system and purge out the obvious air, our job is done. The reality is that as the water heats up, we are going to be squeezing out the entrained air in the system.

Often, I will hear that dirt separators are not getting used because the contractor has never had a boiler heat exchanger fail or they are putting in potable water.

Scale will coat your heat exchanger and cause blisters and failure. Before that happens, it is also negatively impacting your boiler's efficiency because that sludge gets baked right into the heat exchanger impeding heat transfer. I’d suggest paying for the dirt separator, which protects your boiler from not only failure but a drop in fuel efficiency or paying for more fuel for the life of your new boiler and crossing your fingers it does not fail.

Boiler plant strategy

Often, we see designs done where a building needs 500,000 btu/h and the designer will spec a single boiler to cover the load. In many scenarios, two smaller boilers are better than

We also do this exact same thing using a hydronic heat pump with a backup electric or gas boiler to cover the domestic hot water and the coldest years of the day. :

Hybrid systems provide backup heat on the coldest days of the year when a heat pump can’t quite meet the homeowners needs.

Photo provided by Kevin Schmitt

Michael Ridler is a technical services manager at Eden Energy Equipment. He started out working for a Ont-based HVAC company and now focuses on providing field support and technical training to contractors, engineers, and builders on heat pumps, boilers, and all things hydronics. He can be reached at edenenergymike@gmail.com