Round duct adapter on City Multi PDFY

[emes]

Has anyone used Mitsubishi's round duct adapter on a ducted concealed indoor unit?

We have eight PDFY-P18 indoor units and I'm interested in using round ducts for the returns.
Looking a their documentation that unit would use PAC-KD50EDF-F which look like it only has two 8" ports. That's seems like not enough airflow.

Any advice welcome.

[emes]

That's 480 CFM through (2) 8" round duct. At least it looks like 8" to me.

[The Viking]

We normally don't bother with the manufacturer's ductwork adaptors.
We get our ductwork subcontractor to make them instead.
Made to measure so you get the spigots where you want them and the size you want AND normally cheaper than OEM.


Another tip, remove the filter from the unit and fit return air grilles with filter holders in them (saves a lot of hassle when it comes to maintenance)

[Thermatech]

The Mitsubishi UK product catalogue & price list only list accessory drain lift pump, & long life filter & filter box.
No supply plenum box available as standard accessory in UK.
UK contractors always make up there own plenum box which is supplied together with all ductwork for the project.
However to make even cheaper some opt for a simple square box plenum. The result is excesive terbulence in the plenum & poor air flow down the branch ducts. The resulting high static pressure makes the fan work harder & reduced air flow make system efficency reduced.

I have always found that a tapered plenum shape which funnels the supply air down into the branch ducts works much better but costs more to fabricate due to complicated shape.

What type of supply plenum box is Mitsubishi USA supplying ?
If you do some digging you might find that is made to order in USA for Mitsubishi.
I just cant see them shipping pieces of ductwork half way arround the world, would there be enough profit to cover the shipping & wearhouse storage costs?

[mchild]

Attached is a picture of the adapter that is in question. If it were me, I would simply have a short section made that fits the air handler and then attach standard 8" take offs. Any sheet metal shop could do it for a nominal amount.