Serviceability: everyone agrees this is important to consider in design and installation of any equipment. But what does ACTUALLY ensuring serviceability look like?
I’ll post a few things the guys have found on plans to demonstrate how a good commissioning review can fix serviceability issues on paper – before it's installed and when it is cheap and easy to fix!
The above image is from the 100% CD submittal plans from the Design Team (it was also in the 90% submittal – but the Design Team didn't address it then)
This was one issue of exactly 100 issues total that our Cx Agents identified on just two plan reviews for this project.
The issue here is the placement of the VAV boxes: placement is NOT idea for a couple of reasons:
The left box will be difficult to service if it is installed as designed. If there was a leak or other issue, there is no way to access the water lines as they are nearly flush with the wall. The service technician will be reaching up and over the VAV to access valves, vents and actuators depending on where the Contractors end up locating them.
The right box will need multiple ceiling tiles removed whenever servicing or balancing the VAV box. If there is an issue with the VAV box coil for instance, the Service Technician will need to locate their ladder on the left side of the doorway to access isolation valves. They will then need to move their ladder to the other side of the doorway to access the VAV itself.
A frequent comment we end up making is to have the VAV coil connection and piping on the same side as the VAV control panel. This reduces the number of ceiling tiles that need to be accessed and worked around to service a single VAV. It may seem like a trivial deal, but can be a source of a lot of frustration for the Owner Facility Staff when the time comes to service equipment!
Coordination between trades
Something else we regularly run into is coordination between design trades. By simply overlaying layers on the PDF drawings we frequently see issues where other systems will interfere with access to equipment. In the example above, we found where the duct mounted humidifier will be practically inaccessible between adjacent ductwork and cable tray. How is the Owner supposed to service and clean the humidifier?
We frequently run into situations in the field where we can barely get the ceiling tiles out below cable tray due to the mounting height of them. How is anyone supposed to get to the valves, distribution header, etc.?
Why doesn’t the Design Team catch this? Why was it designed this way in the first place?
Plenty of design is done automatically. While programs like BIM modeling help, we still find plenty of items slip between the cracks.
Possibly inexperienced Drafters, with Engineers not familiar with on-site issues that can arise.
Thinking about ACTUAL serviceability is a fundamentally different way of looking at the design of a building. Our Commissioning Agents have direct experience with the pain and cost involved in equipment that is difficult (or impossible!) to service properly: perhaps it takes feeling that pain and frustration to really identify all of those areas that might cause similar problems in the future!
Like Contractors, the Design Team is under a time crunch to get the project out in time for bids. It can be easy to not fit in all of the coordination and reviews of the design documents with an eye to spot potential problems - this is where commissioning reviews can be a tremendous asset!
Don’t the Contractors know this? Why don’t they either ask the Design Team or just move the VAV box?
Depending on who is doing the installation they may NOT recognize these potential problems: it will be super easy to put that thing in when no walls or doors are up yet!
Some experienced Contractors will recognize the potential problems here (especially of the water lines being inaccessible). However, a couple of things can keep them from taking the time to inquire about a fix:
Contractors are under tremendous time pressure to complete the work on site as fast as possible: they are not incentivized to make a call to the Design Team, wait a few days or weeks for a response, and THEN proceed with installation. If they show up onsite to do this installation today, it is getting installed today.
Contractors are well aware of the need to stick with the plans AS WRITTEN, or they can be held liable for problems. You are more likely to find Contractors that will err on the side of installing EXACTLY as designed even if they have a hunch there is room for improvement.
Heat pumps, VAV boxes, and exhaust fans (all equipment really) WILL need to be serviced eventually. With these specific units, assume you will want access to them at least every couple of years after installation.
Speaking of serviceability, other items our team would ask about during design reviews:
What will the ceilings be? Drop ceiling that is easily accessible? That is the best choice! If above a hard lid ceiling, are access doors coordinated and indicated? Can you reach all components necessary from the access points?
Can the unit be easily removed if needed?
Depending on your ceiling…if you don’t plan ahead for this you could be stuck taking that piece of equipment out in pieces. Pro tip: If you can avoid having a torch in your ceiling cutting out equipment that would be best!
Is there a way to disconnect the unit from water and power?
Can a replacement unit be installed if needed?
Is there physically space to get a replacement in?
How can we place units so they will be least disruptive to staff in the place?
Ideally you would want the following for placement of above ceiling equipment:
Above a hallway or an area not commonly occupied and NOT in an office, classroom, patient room, etc.
Accessible to be removed via a lift. Then as a Building Operator, invest in a couple extra units.
If you run into a problem with a unit:
Locate equipment as close to the ceiling as possible. We have run into scenarios where equipment was 6’ ABOVE the lay-in ceiling! The Owner would have had to remove t-bar grid and multiple ceiling tiles and get a lift to go up into the ceiling space to work on those particular VAV boxes!
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