Fijitsu

Snowmelt

Has anyone ever installed a Medium Static Pressure Duct I’m thinking two ton for three bedrooms on second floor

mikeg2015

Not the medium pressure, only the low pressure. Low pressure requires oversized ductwork and best to use all metal (insulated) to keep static pressure low. But is a lot more efficient. I think medium pressure is low efficiency than standard split except in very mild weather.

Needs to have ductwork laid out like any other system. Large filter grill or 5” media filter on the return.

IF installed in an attic, need R8 insulation with vapor barrier and mastic on all joints to seal it up.

I would try and find a closet and locate the equipment if possible inside the conditioned space. 1) easier ot service 2) less losses since coil starts at room temperature on startup. 3) no winter freezing issues for drain.

Make sure you use the heating or run the fan on low in winter or cold ductwork in an attic will fill with condensation.

For only a little more, could just do 3 small heads or ceiling cassettes depending on access. More effficient and will be zoned and no duct losses.

I wish I had gone that route on my own home for my upstairs system.

pecmsg

The duct work is critical. Static pressure must be kept to a absolute minimum.

I’ve installed a few but with straight ducts and there supply grills!

GW

Need a poll—-how many guys actually know how to check pressure 😄

pecmsg

> @GW said:
> Need a poll—-how many guys actually know how to check pressure 😄

Refrigerant or Static?

GW

Static, it’s like everything else, simple once you know where to stick the drill bit


(who can’t screw on a gauge hose) 😄