Fujitsu Downflow Conversion Kit for AMUH Air Handler
Fujitsu’s genuine kit for installing an AMUH multi-position air handler in downflow, with air discharged downward.
AirGreen codeAG-AC-00301
514 316-2973 · sales@airgreen.ca
Quick facts
The Fujitsu downflow configuration kit lets you install an AMUH multi-position air handler so that it blows air downward, into a plenum below the unit. Fujitsu offers it in two sizes, one for each cabinet size of its R-32 air handlers.
For air handlers mounted above their ducts
In many homes in the area, the air handler sits in a ground-floor closet and the ducts run through the basement or the slab. The air then has to go down: that is the downflow configuration. The kit is also used when replacing an old unit already mounted this way, to reuse the existing plenum and duct system.
Two sizes depending on the cabinet
- UTD-DFMSB1: small cabinet, AMUH12KUAS, AMUH18KUAS and AMUH24KUAS air handlers
- UTD-DFMMB1: medium cabinet, AMUH30KUAS, AMUH36KUAS and AMUH48KUAS air handlers
What to plan with the conversion
The air handler’s position is decided before installation, because it determines the plenum connection, the condensate drain route and access to the filter. The air handler’s installation manual governs orientation and drainage. If you are adding a Fujitsu electric heater kit or filter base, we plan for them in the same job.
Installed by AirGreen across Greater Montréal
Our refrigeration technicians install Fujitsu AMUH air handlers in the position that suits your home, in Montréal, Laval, Longueuil, on the South Shore and on the North Shore. RBQ licence 5645-9605-01. For availability or a quote, call us at 514 316-2973 or email sales@airgreen.ca with the air handler model and quantity.
When the air handler has to push air down
An air handler set above its ductwork, on a main floor or in a closet, blows downward: this kit makes that configuration possible.
- Air handler in a closet above a basement duct system
- Replacing an existing downflow unit
- Homes where the supply plenum sits below the air handler
- New slab-on-grade builds with floor ducts
2 sizes, one page
Each size has its own AirGreen code. Tap a row to select it.
| Model | Cabinet | Air handlers listed by Fujitsu | Part no. | AirGreen code |
|---|---|---|---|---|
| UTD-DFMSB1 – AMUH12, 18 and 24 | Small | AMUH12KUAS, AMUH18KUAS, AMUH24KUAS | UTD-DFMSB1 | AG-AC-00301 |
| UTD-DFMMB1 – AMUH30, 36 and 48 | Medium | AMUH30KUAS, AMUH36KUAS, AMUH48KUAS | UTD-DFMMB1 | AG-AC-00302 |
UTD-DFMSB1: AMUH12, 18 and 24KUAS. UTD-DFMMB1: AMUH30, 36 and 48KUAS.
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Pick the size by cabinet: AMUH12, 18 and 24 (small) or AMUH30, 36 and 48 (medium).
- The mounting position is decided before installation: it affects the plenum, drain and filter access.
- Follow the air handler installation manual for orientation and condensate drainage.
- The conversion is a job for a qualified refrigeration technician.
You may also need
Fujitsu Electric Heat Kit for AMUH12-24 Air Handler
Fujitsu Electric Heater Kit for AMUH30-48 Air Handler
Fujitsu Filter Base for AMUH Air Handler
Fujitsu Remote Temperature Sensor – UTY-XSZXZ1
Fujitsu Leak Detection System Accessory – UTYSGZU
GENERAL AIRSTAGE Leak Detection System Accessory – UTYSGZU
Hitachi 5-Wire Adapter for 24 V Thermostat – C3STAT01
Hitachi C1STAT01 5-Wire Thermostat Adapter (airHome)Original partsSee all
Frequently asked questions
Which kit for my air handler?
Fujitsu lists UTD-DFMSB1 for the AMUH12KUAS, AMUH18KUAS and AMUH24KUAS, and UTD-DFMMB1 for the AMUH30KUAS, AMUH36KUAS and AMUH48KUAS. Send us the air handler model number to confirm.
Is it needed for horizontal or upflow installs?
Fujitsu names it a downflow configuration kit. For other positions, follow the air handler installation manual; we confirm what your project needs.
Can it be added to an installed air handler?
Yes, if the unit is being moved or reoriented. The plenum, drain and filter access then need to be reworked.
Can you install it?
Yes. We do the conversion when we install the air handler, everywhere in Greater Montréal.
An AMUH air handler mounted the right way
Tell us the size and the quantity: we confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 7, 2026.