A fluid heating apparatus includes a housing containing a flattened tube and lamps. The apparatus further includes a first conduit flow-coupled to the flattened tube, the first conduit being adapted to provide fluid to the flattened tube. The apparatus further includes a second conduit flow-coupled to the flattened tube, the second conduit being adapted to channel fluid from the flattened tube. The lamps are arranged to irradiate the flattened tube, and the flattened tube is adapted to absorb radiation from the lamps and heat fluid contained therein.