Two ways to model computer room air conditioner units in a service gallery: block the gallery out, or mesh it and duct the supply under the floor.
This video shows two ways to model computer room air conditioner (CRAC) units that sit in a service gallery outside the white space. The demo uses a raised floor room with a ceiling return plenum.
What the video shows
- Enlarge the default room to leave space for the gallery, drag larger CRAC units in from the library, and copy and paste them into position.
- Method one: block out the gallery. Add a column block (slab to slab) behind each unit so the gallery volume is not meshed. The cooling units then act like supply ducts feeding the room.
- Match the block and unit dimensions by keeping two editors open and comparing start positions and lengths. Blocks must sit tight against the units and walls.
- Method two: mesh the gallery. Add a baffle (a zero-thickness object, so it uses few mesh cells) to form the wall, and set a small leakage so the sealed volume is not a dead zone.
- Add blocks in the plenum around each unit to create a supply duct under the floor, and turn on the plenum extension switch so each unit connects to the ceiling.
- Lay out racks, ceiling grills and loads, then run the model and review the HTML report.
Tips
- Gaps between blocks, units and walls make the mesher create many small cells and raise the cell count.
- Dragging an object slightly out of the room lets the auto repair snap it back tight against the wall.
- The presenter prefers the block-out method because it needs fewer mesh cells, though either works.
- Align racks as closely as possible: a cleaner layout gives a smaller mesh, a faster run and better results.