Reimers builds compact commercial electric boilers up to 700 kW in a small footprint. Some are classified as miniature boilers. Care is taken to design them to fit in to small boiler rooms. They are near 100% efficiency and come with UL and ASME certifications. Electric powered means zero on site emissions. There never is a stack or vent to install for combustion gases. Quiet is normal for operation. No fans or motors constantly running.