Lochinvar has expanded its Crest boiler line. The new boilers use fire-tube design to deliver 96.2 percent thermal efficiency and up to 20:1 modulation turndown. The Crest line now includes 10 condensing commercial boilers with inputs ranging from 750,000 Btu/hr up to 5 million Btu/hr.
Crest boilers feature a top-mounted micro-metal fiber burner; the Wave fire-tube configuration creates turbulence as flue gas products flow down the tube, scrubbing the energy. As water flows up the vessel, super-heated flue products flow down the fire tubes. With one pass, heat is transferred and flue gases reach condensing temperatures. Combustion ranges from five percent to the maximum firing rate up to 100 percent as the heating load increases.
The unit is controlled and monitored with an eight-inch touchscreen and multi-color interface, which can be integrated into a building automation system through BACnet, ModBus and other communication protocols using a gateway device.
Up to eight Crest boilers can be sequenced using a two-wire, daisy-chain connection. Cascade sequencing can be programmed for Lead-Lag or Efficiency Optimized operation. The new CREST models also feature cascade redundancy, so if the lead boiler is turned off for maintenance, cascade redundancy automatically shifts the lead role to the second sequenced boiler.
Crest boilers can operate over a range of flow rates with very low pressure drop, allowing for a full flow system. The boiler has six venting options and permits direct-vent air intake and exhaust runs up to 100 equivalent feet. Multiple units can be common-vented.