I’ve covered pellet-fueled boiler applications in several past issues of PME. All of them have involved hydronic distribution systems. While such applications are certainly the prevailing way pellet boilers are used, they are not the only option. It’s possible to couple a pellet boiler to a forced air distribution system.

I recently reviewed a project in which a municipal building was being connected to a district heating system supplied by pellet-fueled boilers.

Over the last several years, I’ve been reviewing submittals for proposed heating systems using pellet-fired boilers. The submittals come from heating professionals ranging from contractors to professional engineers. They’re required for a state incentive program that offers significant rebates to encourage growth of the biomass heating market.

Figure 1 shows a piping layout that was used to retrofit a pellet-fired boiler to an existing 4-zone heating system supplied by an oil-fired boiler.

These webinars are free to attend, and aimed at designer and engineers.

I’m sure everyone reading this column has heard the adage “a picture is worth a thousand words.”  

Because they generate heat intermittently, renewable energy heat sources such as solar thermal collectors and pellet boilers require thermal storage tanks. So do storage-based systems using off-peak electricity, or micro combined heat and power (MCHP) generation.

What remains is to assemble a control system that can orchestrate all the required subsystems.