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From the pics it looks to me that the sealed duct coming into the left side of the return air plenum is you make up air. I believe Diakin requires it to be already conditionded by another unit. It also looks like it is a plenum ceiling return system like some other guys mentioned. Make sure you have return grills in the drop ceiling. And as already mentioned if it is plenum return everything in the drop ceiling has to be rated for it to be code. I know those little AHUs do not produce much static also and duct work can be an issue. As for the filter replacement the service guy is never thought of. It would would cost more money to install to make it properly servicable.

I can't tell by the pics but is that a ducted return. If so the holes make the sub ceiling a plenum. Depending on size of the sub ceiling there might be a fire code problem.
Reasons for poking holes in returns..Not enough RA. Access to filter, coil, drain pan.
By the work it looked like someone was in a hurry and wanted a quick fix.

Since this is a hospital, CYA, once you sign off, could leave you open for a lawsuit. Daikin vrv's r decent equipment, but that would suggest to me that their is adesign problem. Simple as the wrong type box, mounted in that location. Do yourself a favor and ring it up to your boss.

Daikins are odd sizes to get filters for. The usual setups we are used to don't work. The company I work for has been installing these for a few years. Many growing pains involved. Filter bases and sizes included. I think the systems are great tho. Adapt or disappear.

It's not pretty BUT

It does give you a filter rack with a larger filter (given the angle) and it will reflect some of the insertion noise from the unit ( vs if the filter was right on the end of the unit.
This will not win any sheet metal craftsmenship awards but no technical rules broken as far as I see

If anything the plenum should have been lined with opening on top with a filter rack there to baffle some of the noise. That looks ugly, hard to access filter but I don't think it will affect operation at all. Hopefully that's not how the engineer drew the details then I would hate to see the rest.

rack works best.they have a special type unit for fresh air. we lined all of our r/a ducts before install, if they dont have enough return they scream

Originally Posted by billymons

This is a smaller out building not the main hosp. Not a steril environment. No surgeries or anything in this bldg. there are other separate units for fresh air.

again if you want to dig into this further get the installation material, mechanical drawings, (if any) and warranty stuff and read through it. but what you will find at the end, they got what they paid for.

Originally Posted by aNtHoNyNoZ

Being that its a hospital arent you required to have fresh air? Are these units the means for that fresh air?

This is a smaller out building not the main hosp. Not a steril environment. No surgeries or anything in this bldg. there are other separate units for fresh air.

Originally Posted by billymons

Yea looking like this, why even have a return plenum just put a filter rack and be done with it. Thats what I told the contractor. He hasnt responded yet.

Being that its a hospital arent you required to have fresh air? Are these units the means for that fresh air?

Yea looking like this, why even have a return plenum just put a filter rack and be done with it. Thats what I told the contractor. He hasnt responded yet.

Lining the RA plenum would quiet it tremendously!

looks really bad.They may have done this to allow more return air to quiet the units.My company sells these units and they get real noisey when they dont have enough return air

I probadly would have fabricated a filter rack with a access door big enough to remove for maintenace. However contractors cant provide textbook work when access is limited. Im in new york so im used to it. This install looks fine by looking at these two pics.


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I am here: http://maps.google.com/maps?ll=40.730896,-73.866351

Haven't got in to one yet looking forward to it to see what they are made of and try eyes operate

Daikin has a very, very specific warranty policy. If i were you i would request all the information about the equipment. The vendor should give this all over to your company anyway. With the warranty info and the engineer that designed it will make the determination if the installation was done correctly. However, that may not make changing filters easier, that comes when the installation was be done and someone from maintenance saying WTF how do you expect us to change these!and than making a field change. many design engineers and HVAC vendors don't think about the maintenance guys

Daikin sucks you cant get economizers for them in the US but they sell 8 ton air handlers go figure

Hacktacular.

Get your spec book and read up or bring it to the ME's attention and let him decide if this meets the project documents.

looks like a ceiling return plenum kinda looks like crap wonder how much air gets around the filter. aside from that it probably work

That is ugly.................really ugly!