teresa,
teresa,

Where are you reading those relative humidity numbers? If it’s in the air coming off the coil or right out of the supply vent, it’s probably fine. Relative humidity doesn’t really tell you how humid the air is unless you also know the temperature. For 60° F air at 80% RH, the dew point is about 54° F. Air conditioned to design conditions (75° F and 50% RH) has a dew point of 55° F, so you’re right there. See my article on this:

The Problem with Relative Humidity
http://www.energyvanguard.com/blog-building-science-hers-bpi/problem-with-relative-humidity

If, however, the air in the room is hitting 77% or 89% at normal room temperatures of ~75° F, then you have a problem.

A few questions.

How did you come by the photos?

Did you become involved in any way?

Has the photographer who iPhoned the photos out of that flex duct jungle been rescued or are they still MIA?

“The craft of sheet metal is dying with the generation that is now retiring. David Hill at #bscamp.”

To which I replied:

“Flex duct syndrome. Each time we make it easier to install, we make it easier to get bad results.”

That evening in Joe’s backyard this topic arose again, and I mentioned “flex duct syndrome”, and how it can also be seen in the adoption of CSST (corrugated stainless steel tubing) to replace black iron pipe for natural gas piping in a house. Easier to install, easier to run it where roofing or drywall nails punch a hole into it, filling an attic or wall cavity with explosive gas.

The craft of sheet metal and other crafts are dying because the demand for these crafts is diminishing, largely replaced by “string it out and hope for the best” mentality that unfortunately so often follows a material like flex duct and CSST.

The original intent for flex duct was to be the final short run of duct between a metal branch and a diffuser in a suspended ceiling. Personally I think that application is where flex should have remained. Yes, it can be installed properly as an all-flex system in a residence, but how often is that done? So often this stuff is installed in hot weather, and installers want to get it in and themselves out of the attic as soon as possible. Careful attention to detail tends to slip in this environment.

All of this discussion only strengthens my case for getting ducts and air handlers out of the attic altogether. Just a matter of getting home buyers and builders to realize the value of HVAC and ducts in conditioned space far exceeds the small sacrifice of square footage to accommodate it. Time to let go of 20th century archaic practices (based on the myth of perpetually cheap energy and resources)

Only place I could find to
Only place I could find to submit a comment. Is that unit really just sitting on four concrete blocks, on end, as it appears? If so, it is a violation of the law in a bunch of places. Hope they are not in a state with earthquakes… which would rule out all 50.

Looks like a bigger in-line
Looks like a bigger in-line fan on that one. Maybe the flex duct was collapsing so they put in a rigid duct?