Plain-language definitions

Glossary

Plain-language definitions for common commercial boilers and boiler plants terms.

Packaged boiler

A factory-assembled boiler supplied as an integrated equipment package.

Condensing boiler

A boiler designed to recover heat by condensing water vapour in flue gas under suitable conditions.

Equivalent full-load hours

Annual useful load expressed as the number of hours at full capacity.

Make-up water

Water added to replace losses from a boiler or steam system.

Blowdown

Controlled removal of boiler water to manage dissolved solids and impurities.

Economizer

Equipment that recovers heat from flue gas to preheat water or air.

Burner turndown

The ratio between maximum and minimum stable burner firing rates.

Hydronic system

A heating system that circulates water to deliver heat.

Refractory

Heat-resistant material used in combustion and high-temperature areas.

Authority having jurisdiction

The organization responsible for applicable approvals and enforcement.