Hello,
We're building a new, 450 sq.ft server room in a gut-and-remodel SoCal building. I work for the owner. We'll be using LG Multi V high-static VRF units to cool it (they already arrived), which along with the ductwork will occupy adjacent rooms' ceilings too. Space and clearances are especially a concern.
Specifically, the mechanical engineer overlooked a large structural concrete beam that spans the entire building: the reflected ceiling (stamped) plan calls for a 9'0" finished (drop) ceiling, while the mechanical plan as-is would result in 7'0" ceilings in multiple offices, had I not flagged this.
We already had lengthy meetings with the owner, general contractor, ME, and HVAC contractor. I was able to get the ME to allow going down & up around the beam, thank goodness; but the decision was basically to avoid any major redesign — so the remaining consideration is the ductwork insulation.
At the meeting, the HVAC contractor insisted that all ductwork in this system must be 3" around — adding an entire 1/2 ft of height (and width) to the ductwork — because it has to meet R-8 and to pass inspection. My ACCA manuals & Title 24 knowledge is sporadic… but this did bring up multiple questions:
1. There's no code/inspection need for any specific thickness of insulation, correct? It's about meeting certain R-values under the applicable conditions, no? (And 3” just happens to be the typical 0.75 Lb/ft² fiberglass thickness needed to meet R-8.)
2. He stated, "R-8 is typically required for all commercial applications". Isn’t R-8 only for outdoors ducts, uninsulated attics at the perimeter of the building envelope, and other such unconditioned spaces? This is in 1st floor, isn't everything considered a conditioned space, then, requiring only R-4.2 ?
3. Does the entirety of the ductwork need to be insulated? From what I understand in Title 24, yes. But unlike the con call, his recent email appeared to change course: "Insulation is required for the return duct while it’s outside of the server room; inside the room, we recommend it."
This came up after I pointed out the electricians had mounted a couple of pull boxes where (thick) ductwork needs to be, causing a major clearance conflict. Suddenly insulation became optional.
4. Ecofoil R-8 duct wrap seems especially promising in this situation. From what I understand, despite being a radiant (reflective) insulation material, it includes 3 air layers/pockets to create an effective conductive and convective barrier and earn the high R-value. It could save 4.5" on the width & height, which would certainly help. He just said he's not familiar with the material. Any reason not to use it in this case?
Would you use it throughout the ductwork, or only in the space-constrained sections around the beam & stick to fiberglass elsewhere? Or doesn't matter?
(Was gonna link to the cut sheet but can't post links)
I just want to solve this so we can all move on, and every inch matters… to give my fellow employees a less claustrophobic working space, and give us technicians room in the server room.
Thanks in advance, and happy holidays!
We're building a new, 450 sq.ft server room in a gut-and-remodel SoCal building. I work for the owner. We'll be using LG Multi V high-static VRF units to cool it (they already arrived), which along with the ductwork will occupy adjacent rooms' ceilings too. Space and clearances are especially a concern.
Specifically, the mechanical engineer overlooked a large structural concrete beam that spans the entire building: the reflected ceiling (stamped) plan calls for a 9'0" finished (drop) ceiling, while the mechanical plan as-is would result in 7'0" ceilings in multiple offices, had I not flagged this.
We already had lengthy meetings with the owner, general contractor, ME, and HVAC contractor. I was able to get the ME to allow going down & up around the beam, thank goodness; but the decision was basically to avoid any major redesign — so the remaining consideration is the ductwork insulation.
At the meeting, the HVAC contractor insisted that all ductwork in this system must be 3" around — adding an entire 1/2 ft of height (and width) to the ductwork — because it has to meet R-8 and to pass inspection. My ACCA manuals & Title 24 knowledge is sporadic… but this did bring up multiple questions:
1. There's no code/inspection need for any specific thickness of insulation, correct? It's about meeting certain R-values under the applicable conditions, no? (And 3” just happens to be the typical 0.75 Lb/ft² fiberglass thickness needed to meet R-8.)
2. He stated, "R-8 is typically required for all commercial applications". Isn’t R-8 only for outdoors ducts, uninsulated attics at the perimeter of the building envelope, and other such unconditioned spaces? This is in 1st floor, isn't everything considered a conditioned space, then, requiring only R-4.2 ?
3. Does the entirety of the ductwork need to be insulated? From what I understand in Title 24, yes. But unlike the con call, his recent email appeared to change course: "Insulation is required for the return duct while it’s outside of the server room; inside the room, we recommend it."
This came up after I pointed out the electricians had mounted a couple of pull boxes where (thick) ductwork needs to be, causing a major clearance conflict. Suddenly insulation became optional.
4. Ecofoil R-8 duct wrap seems especially promising in this situation. From what I understand, despite being a radiant (reflective) insulation material, it includes 3 air layers/pockets to create an effective conductive and convective barrier and earn the high R-value. It could save 4.5" on the width & height, which would certainly help. He just said he's not familiar with the material. Any reason not to use it in this case?
Would you use it throughout the ductwork, or only in the space-constrained sections around the beam & stick to fiberglass elsewhere? Or doesn't matter?
(Was gonna link to the cut sheet but can't post links)
I just want to solve this so we can all move on, and every inch matters… to give my fellow employees a less claustrophobic working space, and give us technicians room in the server room.
Thanks in advance, and happy holidays!
