Negative Pressure Heat Transfer System

envirosep HTS-NP
The envirosep HTS-NP heat transfer system with closed loop condensate return features the latest technology in steam-heating applications which allows the heat transfer system to operate under vacuum conditions on the steam side. The envirosep HTS-NP permits energy savings up to 15% versus conventional building hydronic heating systems. No vent is required in the condensate system, eliminating the unsightly exhaust flumes in conventional systems. The envirosep HTS-NP incorporates condensate pumping, eliminating the need for additional condensate handling units. Each system is custom-engineered to meet specific site requirements. The most remarkable feature of the envirosep HTS-NP is the ability to provide a cost reduction while providing heating system hot water at a controlled flow rate. This fully integrated turn-key system speeds installation and start-up which provides significant, initial-investment savings to contractors, engineers, and building owners.


  • ASME, shell & tube heat exchanger – U-tube, with U-stamp
  • Base-mounted, end-suction pumps
  • Condensate recovery system
  • Vortex air separator, with auto air vent
  • Bladder expansion/compression tank
  • Triple duty valves & suction diffusers
  • UL-Listed NEMA 12 industrial control panel
  • Float & Thermostatic Steam Trap
  • Pilot-operated, motor-operated, or pneumatic-operated control valves
  • Make-up water assembly, with safety relief valve
  • Microprocessor based temperature controller
  • ASME Section IX Welding


  • PLC system controller w/ touch screen
  • NEMA 7/9 explosion-proof rating
  • Flexible pump connectors
  • Seismic or vibration isolators
  • Plate & frame heat exchangers
  • Vertical inline centrifugal pumps
  • Combination air & dirt separator
  • Specific performance criteria (upon request)
packaged pumping systems
industrial control panels

Contact us to learn more about Envirosep solutions.

We offer integrated solutions for your fluid handling, heat transfer and energy recovery needs.