Coil Cleaning - Heating so slightly OT

[Brian_UK]

Haven't seen the problem yet but apparently we have a large(ish) air handling unit which has had poor filter maintenance on it the LPHW heating coil is badly blocked on the airside.

Any suggestions on the best way to get it clean again?

Bearing in mind that the AHU probably won't have a duct drain adjacent to the coil our first thought of a pressure washer may have to go on the back burner for the time being.

Does anyone know of a good cleaning chemical that would shift several years worth on baked on dust and dirt?

Coil is copper I believe.

[chilliwilly]

Can you get the filter out. Soak in hot soapy water maybe then reverse blow off with OFN.

[stufus]

Hey Brian
I had a similar problem recently and got a product from Gasco i think called zip clean ,

its an aerosol foaming spray that doesn't require flushing afterwards.
Just whack it on ,let it gobble away an hoover up the crap afterwards. Handy stuff if drainage is a problem

[Brian_UK]

^^ Thanks guys, they've got the filter remains out already and making new frames for some new filters.

I was thinking about a foam, I'll look that one up, thanks.

[frank]

The other alternative is to remove the coil from the AHU if this is possible, and then pressure wash to your hearts content.

We're going around at the moment removing burst LPHW frost coils from AHU's and carrying out on-site brazing repairs.....

Roll on Thursday when the cold weather returns.....loads more work :D:D

[monkey spanners]

I've had a few cellar cooler coils that have blocked up, one we removed and pressure washed outside, another i made a chute out of a tarpaulin to catch the water and direct it into one of those big gorilla tubs/buckets and washed it out with some coil cleaner and rinsed.

Have found an air line with a propper blow gun good at cleaning dust and straw out of condensers on farms when customer has been bright enough to install stuff in the loft, only down side is you get covered in dust.

Jon :)

[Brian_UK]

Actually went to site today for a look-see.

Crap, that kit is old... It's a air supply fan for a swimming pool built around the time that Noah took up swimming lessons.

I had thought, before arrival, of removing the coil - hah, no chance. I was stood next to the section with the coils in. Two coils back to back, frost and reheat mounted horizontally.

Size, about 2.5m square, case constructed out of 1/4 plate by the looks of it and with enough services running around to provide the odd space to get a pair of steps through.

Under the coil deck, a good 9 feet under, in a hole in the plant room floor is the fan section. Now that's held together with hardboard, plywood and gaffer tape. It just keeps getting better.

Anyway, found the ladder to put down the hole to reach above the hole and prise open an old filter access door.

Do you know, things might be looking up after all. It looks like the crud on the coil face is actually pieces of rusted metal that have been falling off the various bits of tin that were the frame for the filters. So I might get away with a simple vacuum cleaner job.

Still a sh!te job but there you go. ;)

[mad fridgie]

"If in doubt - Biff it out"
Saying of Ex Prescold service manager

[Brian_UK]

^^ Quite right too ^^

Anyway got the job done today.

Luckily the ductwork contractor was on site preparing a large access plate and new filter frames. He fitted it and then removed it so I had a decent sized hole to work through.

Filled up two vacuum cleaner, Henry, bags with the crap of the coil face; rusty metal, fluff, seagull feathers you know the sort of thing.

A good spray with some Pro-Clean and it doesn't look too bad allowing for the partially corroded fins due to sea air.

Mind you, you could hear the fan coming on load as the coil was cleaned.

Usual good working area though, stood on tiptoe on the top of my steps working through a 1ft, 300mm, gap between pipes and the unit.