Fisen is your one-stop shop for anything special: Call us to customize your Rooftop Unit, Air Handler, Chiller, or other HVAC equipment. The following is a list of our robust capabilities, but we also love a challenge. If you don't see what you're looking for here, call us to discuss your specifications.

Replacement or New Multizone units

- Any existing brand
- Dual or Triple deck arrangements
- VAV Multizone, Zoned reheat
- Indoor or outdoor

Special Unit Paint and Coatings

- Hot-Dipped Glavanization
- Electrostatic painting

100% Outside Air Treatment
- Refrigeration customizations

- Low airflow specials

- Heat: Electric, Gas, Steam or Hot water

- Stepped or 100% modulation
- Custom control sequences

Energy Recovery Wheels
- Aluminum, plastic, composite

Energy Recovery Plate HX
- Aluminum or Cellulose

- In RTUs or AHUs

Refrigerant Customizations
- Hot gas reheat
- Hot gas bypass
- Water or air cooled
- Low ambient – 40 deg F
- Alternative refrigerants
- 100% OSA content

VAV / VFD - Any Small Tonnage RTU

- True VAV on units 3-25 Tons
- VFD’s added: Line reactors, Bypass
- Hot gas bypass or freeze stat
- Discharge air control
- Any brand controller for unit operation

Special Controls

- Points integation and programming
- Honeywell
- Johnson
- Trane
- Automated logic
- Siemens
- Others

Electrical Special Options
- Dual point power
- Chicago code modifications
- International voltages
- Single phase power on 3 phase units

Chiller modifications
- Pumping packages

- Mechanical rooms

- Load or expansion tanks
- Indoor or Outdoor
- Automated lead lag
- Pumps, VFD or CV

Rooftop Unit Modifications
- Vertical up flow modification
- Convert down flow units to horizontal
- Double wall construction
- Add modulating power exhaust
- Preheat modules for high OSA %
- Air flow measuring stations
- Stainless steel / composite drain pans
- Demand control ventilation
- Addition of plenum fans
- Wiring in conduit or seal-tite
- Modulating hot gas reheat

- Powered return fans

Under Floor Applications
- Hot Gas reheat

- Return air bypass

- DX coil bypass

- DX coil face damper

- Adjustable DAT

Special Gas Heaters and Gas Trains
- SS heat exchangers
- 1 to 100% heat modulation
- Up to 5,000,000 BTUH

- Drum and tube, in shot, and clamshell

Ultra Quiet Customization

- Chillers, Air Handlers, Rooftops
- Sound levels as low as 48 dBa
- Tailored to individual job requirements
- Independently tested results
- Sound power ratings

- Sound pressure by octave band