Rinnai’s tankless rack system makes multiunit, condensing tankless water heater installation easier and more flexible for commercial contractors. The system is available in free-standing or wall-mounted options for indoor or outdoor applications and can be ordered, built and shipped fully assembled, including gas and water manifolds. Indoor installations can be configured with either standard polypropylene concentric venting or its new common venting system. Individual racks can hold between two and six of the company’s 199,000-Btu condensing units. For even larger systems, multiple racks can be banked up to 25 units and nearly 5 million Btu of input capacity.