TechEngineering2021
Computer
I'm looking to design a custom solution using existing components that are available to me right now. I expect to receive plenty of comments saying why when xyz pre-made solution like diy mini splits are available or why this is a bad idea, but I'm looking for input from those of you that enjoy custom designs, especially using components currently on hand. This is one of those "Is this possible" design scenarios that I want to work through. The answer may ultimately be, it's impossible, but I'm ready to figure this out as though we are currently lost in space with our HVAC system failing and it's imperative we figure out how to do this or we all die.
What I have: 4x Tripplite SRCOOL7KRM mounted in 4 separate racks, but all the equipment requiring cooling is in a single rack. For the purpose of this discussion, all equipment must stay in the single rack.
Racks are arranged in a hot isle/cold aisle like this:
Front of Rack
| |
Rear of Rack
[Contained hot asile]
Rear of Rack
| |
Front of Rack
The problem: These units are essentially window units. There is no other HVAC in the current server room. Currently I am venting the condenser heat down through a 6" floor in 3.25" x 10" insulated ducts and up concrete block walls into the space above the grid ceiling in another room. The problem with this is that the residual heat (125f) is radiating through the concrete block walls which I can't insulate. This is also causing negative pressure so the AC is sucking air from outside the room. During the workday, this isn't a problem because the rest of the building is at 72. After hours however, the rest of the building can get up to 90F so the air it's pulling in is obviously not conditioned. My current solution to keep the room at decent temps but has multiple portable units which is only increasing the negative pressure with compounds the issue.
What I want: I only need the air feeding the primary rack to be cold. I have a hot/cold aisle containment design going on currently with the racks. My idea is to turn the 4x Tripplite units into mini split units. I am going to have to buy anything I need out of my personal pocket so the budget needs to be kept at an absolute minimum. I'm already working on my 608 certification and have the recovery and charge components available to be loaned to me so that I don't have to buy a $600 recovery unit.
Here are my current design thoughts for which I need input.
Solution 1: Remove the evaporator coils from the Tripplite units and put them in a custom enclosure rack-mounted at the bottom of the primary rack to where they would be like this (Front of rack | | | | Rear of rack). Air would feed from the hot isle through all 4 (or less) evaporators, exit through a conduit which is forcing the air upwards towards the servers in the rack. The front of the rack would be using the magnetic sheets that allows there to now be a channel of air. My servers are pulling a total of 600CFM so this solution may not work purely from a CFM standpoint but let's focus on the stacking horizontally of the coils in front of each other like this | | | | for this solution. Is this feasible to do this and cool the air properly? I can obviously run 4 separate line sets for this. If there is a design where I can share one same line set for all 4 evaporators, 4 compressors, and 4 condensers, major bonus points to whoever can explain how I would do that. I know there are designs out there for multiple stages, but obviously these being 4 separate coils in this configuration makes this different. Condensers will be roughly 25-50ft away from the evaporator coils.
Solution 2: I can convert each unit into a mini split and house each unit in a separate rack. I would keep the existing Tripplite enclosure inside and build a custom enclosure on the roof for the condenser units. The same question is asked as to whether or not a single line set can be used for this or if I need to run separate line sets.
The obvious: I'm going to have to handle additional motor(s) since the current units share a single motor for both the evaporator and condenser. I currently plan to stack the 4x condenser coils in a 2x2 array and use a single larger fan to cool them. I'll also have to handle pumping the condensation away from the evaporators regardless of design.
In a years time, I will be able to get a 24k-36k mini split if this design isn't efficient. I'm really hoping though that I am able to pull this feat off. In the meantime, I need to make this work if at all possible.
What I have: 4x Tripplite SRCOOL7KRM mounted in 4 separate racks, but all the equipment requiring cooling is in a single rack. For the purpose of this discussion, all equipment must stay in the single rack.
Racks are arranged in a hot isle/cold aisle like this:
Front of Rack
| |
Rear of Rack
[Contained hot asile]
Rear of Rack
| |
Front of Rack
The problem: These units are essentially window units. There is no other HVAC in the current server room. Currently I am venting the condenser heat down through a 6" floor in 3.25" x 10" insulated ducts and up concrete block walls into the space above the grid ceiling in another room. The problem with this is that the residual heat (125f) is radiating through the concrete block walls which I can't insulate. This is also causing negative pressure so the AC is sucking air from outside the room. During the workday, this isn't a problem because the rest of the building is at 72. After hours however, the rest of the building can get up to 90F so the air it's pulling in is obviously not conditioned. My current solution to keep the room at decent temps but has multiple portable units which is only increasing the negative pressure with compounds the issue.
What I want: I only need the air feeding the primary rack to be cold. I have a hot/cold aisle containment design going on currently with the racks. My idea is to turn the 4x Tripplite units into mini split units. I am going to have to buy anything I need out of my personal pocket so the budget needs to be kept at an absolute minimum. I'm already working on my 608 certification and have the recovery and charge components available to be loaned to me so that I don't have to buy a $600 recovery unit.
Here are my current design thoughts for which I need input.
Solution 1: Remove the evaporator coils from the Tripplite units and put them in a custom enclosure rack-mounted at the bottom of the primary rack to where they would be like this (Front of rack | | | | Rear of rack). Air would feed from the hot isle through all 4 (or less) evaporators, exit through a conduit which is forcing the air upwards towards the servers in the rack. The front of the rack would be using the magnetic sheets that allows there to now be a channel of air. My servers are pulling a total of 600CFM so this solution may not work purely from a CFM standpoint but let's focus on the stacking horizontally of the coils in front of each other like this | | | | for this solution. Is this feasible to do this and cool the air properly? I can obviously run 4 separate line sets for this. If there is a design where I can share one same line set for all 4 evaporators, 4 compressors, and 4 condensers, major bonus points to whoever can explain how I would do that. I know there are designs out there for multiple stages, but obviously these being 4 separate coils in this configuration makes this different. Condensers will be roughly 25-50ft away from the evaporator coils.
Solution 2: I can convert each unit into a mini split and house each unit in a separate rack. I would keep the existing Tripplite enclosure inside and build a custom enclosure on the roof for the condenser units. The same question is asked as to whether or not a single line set can be used for this or if I need to run separate line sets.
The obvious: I'm going to have to handle additional motor(s) since the current units share a single motor for both the evaporator and condenser. I currently plan to stack the 4x condenser coils in a 2x2 array and use a single larger fan to cool them. I'll also have to handle pumping the condensation away from the evaporators regardless of design.
In a years time, I will be able to get a 24k-36k mini split if this design isn't efficient. I'm really hoping though that I am able to pull this feat off. In the meantime, I need to make this work if at all possible.