Cooling Desing ACRD101

[luizyto_apc]

Hello I have a small Data Center with a single row racks and four ACRD101 equipements.

I want some help to confirm if the desing and configuration of the room is ok.

The configuration is as follow: 

AIR04 - RACK1 - RACK2 - AIR01 - RACK3 - RACK4 - AIR02 - RACK5 - RACK6 - AIR03 -RACK7 - RACK8 the room is 2,6 meters wide, 2,77 meters high and 7,9 meters large. 

The AIR01 is configured as SPOT-Discrete mode and the Fan is at 87% speed with 10.1 KW consumed. The AIR02 is configured as IN-ROW mode at 62% Fan speed with 7.5 KW consumed. The AIR03 is off at moment due to a problem with the compressor. The AIR04 is configured as IN-ROW mode at 28% FAN speed with 3.6 KW consumed. 

My question is if this configuration fits with my Data Center and if the Airs are working ok. Should I change some configuration? The AIR04 should be working more faster?

Below are the metrics:

AIR01

Operating Mode:	On
Compressor State:	On
Cool Output:	10.1 kW
Cool Demand:	10.1 kW
Rack Inlet Temperature:	19.7 °C
Supply Air Temperature:	16.6 °C
Return Air Temperature:	26.5 °C
Suction Temperature:	13.4 °C
Air Flow:	912 L/s
Fan Speed:	87.5 %
Hot Gas Bypass Valve Position:	0.0 %

AIR02 

Operating Mode:	On
Compressor State:	On
Cool Output:	7.5 kW
Cool Demand:	7.5 kW
Rack Inlet Temperature:	19.9 °C
Supply Air Temperature:	17.7 °C
Return Air Temperature:	25.8 °C
Suction Temperature:	15.2 °C
Air Flow:	634 L/s
Fan Speed:	60.9 %
Hot Gas Bypass Valve Position:	19.43 %

AIR04

Operating Mode:	On
Compressor State:	On
Cool Output:	3.6 kW
Cool Demand:	3.6 kW
Rack Inlet Temperature:	19.9 °C
Supply Air Temperature:	17.9 °C
Return Air Temperature:	26.0 °C
Suction Temperature:	17.7 °C
Air Flow:	287 L/s
Fan Speed:	27.6 %
Hot Gas Bypass Valve Position:	74.25 %

Thank you

[BillP]

Hello Luis.

First, can you get the rest of the status information (suction and discharge pressures, superheat, cool set point and supply air set point, Condenser in and outlet temps) off the AIR04 unit? This will allow us to look over the entire unit and see if anything is going on.

Next, the different modes (INROW, Spot, RACS) will have the unit using different sensors to control how much the unit is cooling. In INROW mode, the unit will be using the rack inlet temp sensor to cool. It will try and keep the rack temp sensor at the cool set point. If your cool set point is 20C, then this could be why the unit is keeping its fans slow as it is showing 19.9C for the rack inlet sensor. As other things can cause the unit to run the fans slowly I would still like to see the rest of the information off the unit before confirming that this is what is causing the fans to run slowly.

Lastly, in a row of racks, there generally will be different heat loads across that row. If all your servers are down by AIR01 and your UPS and networking equipment is by AIR04, then the AIR01 will see a much higher heat load then AIR04. This is simply because servers will put out al lot more heat then network switches and UPS. This could be another reason why AIR01 is cooling more then AIR04. There is no issue with running this way.

If you can get the requested information above, we can look over the unit and see if we can find anything. You can also call your local tech support to look at this information over the phone, if you would like to talk to a person. The number can be found off our website www.apc.com under support.

Thank you

[luizyto_apc]

Hello, Yesterday I fixed all the Equipments IN-ROW mode because I had a problem with High Pressure with AIR01, today I had a problem with low pressure with AIRE04 so I changed it to SPOT mode but the pressure continues low. I added a picture with the DC layout. I think I need reconfigure all the equipments but I am not sure what is the best configuration for my DC, mixed or all in SPOT or all in ROW. In other hand I should have other sensors for the ambient temperature or I can use the Rack Inlet Temperature of the four equipments?

Below are the rest of information:

Supply AIR setpoint for all : 19 - cool Setpoint: 22

Please let me know if something is missing!

AIR02

Unit Detailed Status
Input State:	Open
Output State:	Open
OHE Input State:	Closed
OHE Output State:	Closed
Filter Differential Pressure:	27 Pa
Suction Pressure:	895 KPa
Discharge Pressure:	2447 KPa
Superheat Temperature:	19.6 °C

AIR01

Input State:	Open
Output State:	Open
OHE Input State:	Closed
OHE Output State:	Closed
Filter Differential Pressure:	27 Pa
Suction Pressure:	985 KPa
Discharge Pressure:	3327 KPa
Superheat Temperature:	5.2 °C

AIR04

Input State:	Open
Output State:	Closed
OHE Input State:	Open
OHE Output State:	Open
Filter Differential Pressure:	10 Pa
Suction Pressure:	625 KPa
Discharge Pressure:	1293 KPa
Superheat Temperature:	35.2 °C

[BillP]

Hello Luis.

First, I am concerned with the pressures in AIR04. It looks like it is low on charge, which would indicate a leak in the system. The pressures should be around AIR02 pressures.

Next, the rack inlet sensors should be placed in the front of the rack to measure the temperature of air that the equipment is receiving to keep it cool. This would act as the ambient air sensor as it is measuring the air temp that the servers are seeing at their intakes.

For the setup of the room, keep AIR04 in Spot as it has a different heat load with the networking equipment then the other cooling unit. The other three, can be kept in InRow or RACS to cool down the servers. If you do make a change, let the units run for a few hours and watch the temperature sensors to make sure the units are maintaining a proper temperature for the equipment in that mode.

Thank you

[luizyto_apc · Accepted solution]

Thank you very much, I will set those configurations. About the AIR04 the tech support has found a leak in the system so they will replace a valve to fix it. 

Thank you very much for helping me, regards.