Gas-fired Unit Heaters Home /Products/Heating/Gas-fired Unit Heaters PROPELLER TYPE POWER VENTED MODINE HOT DAWG® (HD) MODINE CLAM SHELL VERTICAL (PDP) MODINE TUBULAR LOW PROFILE (PTP) SEPARATED COMBUSTION MODINE HOT DAWG® (HDS) MODINE TUBULAR LOW PROFILE (PTS) HIGH EFFICIENCY CONDENSING MODINE EFFINITY™ (PTC) BLOWER TYPE POWER VENTED MODINE CLAM SHELL VERTICAL (BDP) MODINE TUBULAR LOW PROFILE (BTP) SEPARATED COMBUSTION MODINE TUBULAR LOW PROFILE (BTS) HIGH EFFICIENCY CONDENSING MODINE EFFINITY™ (BTC)