The new Rheem-Ruud Spiderfire line of condensing commercial water heaters offers a wide range of BTU inputs, all with thermal efficiencies of 92% to 95%. The most powerful unit has an input of 350,000 BTUs per hour and can deliver 460 gallons of water per hour at a 100-degree rise. Lower-input models (130,000, 160,000, 199,000, 250,000, and 300,000 BTUs per hour) are also available. All come with a 100-gallon storage tank and can operate on natural gas or liquid propane and can be installed as a single-pipe, power-vented product, or as a two-pipe, power-direct-vented product. The unit can be vented through standard PVC or CPVC tubing, rather than more expensive, large-diameter metal B-vent.