List of Questions for CARRIER FV4B 02 Direct Expansion Fan Coil Unit

List of questions for CARRIER FV4B – 02 – Direct Expansion Fan Coil Unit

For info place has been a rental for 10 years so bare minimum done to the Fan Coil unit. I also think there is a condensate leak from the pipework.

1. Power can checks out. Two red and two black wires. NO white. If fan coil running makes no difference to the fan coil unit , it keep on running. Guess its for start up only.
2. Have moved the second condensate line with the float switch to horizontal. Have removed float switch and operated it manually. It cuts out as it should. Seems to be on a timed trip for re operating the fan coil unit.
3. Is there an internal tray that catches the condensate if the outlet is pointing up hill? If so, where does the condensate flood out from? Does it come out near the air filter?
4. Main condensate line has no trap in it. See attached photo. Does that matter?
5. Air intake plenum below the unit, see attached photo is the noisiest part of the installation? Is there anything that can be done for that? Suggestions. Its like a howling wind when operating.
6. How does the condensate get connected to the drains normally?
7. What does the 1” insulated copper pipe do? When cooling its lagged as its heavily condensated.
8. What does the small un insulated pipe do? (see pictures)

I should add that this summer the motor unit was replaced whilst we were out of the country.

What I am looking to do is to ensure any piece of equipment runs and drains efficiently as intended, and is quiet. It is very very loud at the minute. Incidentally its mounted in a cupboard on the upstairs landing of the house. So the air intake plenum grille is below the unit. This is 2.5ft x 1.5 ft approximately in section.

For the noise was considering taking out the nylon mesh grid and modifying the air intake plenum to take a disposable paper filter as commonly found in domestic stores. Would this help?

Also considering taking off the lagged insulation and adding rigid sheet insulation up to 4” thick or just more loose rockwool.

It may just be it’s a noisy unit, and there is little that I can do.

Finally have taken covers off front for pictures of internals. See attached. It looks like the condensing unit is on its last legs due to the corrosion present on the main cooling coils. All back on now, but all looking a bit worse for wear.

Any thoughts welcome. I think this covers everything I have been thinking about.

Regards

Neil Ware