Heat of Cisco switch and HVAC calculation

[Waldo Roca Martin]

Hi

A costumer is asking us how much heat a 3650 switch are producing to calculate the HVAC for cooling. We are cheeking the DATA-SHEET but the only information about this is is the Airflow and Operating temperature.

Anyone knows where we can find this information?

thank you

Best Regards

[Philip D'Ath · Accepted solution]

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/hardware/installation/guide/Cat3650hig_book/HIGSPEC.html

PWR-C2-1025WAC: 3497 BTUs per hour, 1025 W
PWR-C2-640WAC: 2183 BTUs per hour, 640 W
PWR-C2-250WAC: 853 BTUs per hour, 250 W

[Waldo Roca Martin]

Hi

Thank you so much for the answer.

Hardware intallation Guide...... I should've guessed :)

Best regards

[Philip D'Ath]

*** OOPS *** You have already rated and marked the answer as correct.

[Elliott Willink]

I know this has already been marked as a correct answer, but it really needs some serious clarification, as I see this kind of stuff being drawn up off data-sheets all the time:

Cooling calculations for switches should only be *very* loosely tied to BTU output of the power supply, with special attention to PoE scenarios. Keep in mind a few things:

- Your 250/640/1025W power supply almost certainly won't be dissipating 250/640/1025w of heat at the switch, unless at absolute-max load, at environmental limits, and all PoE devices are in the same room.

In a PoE scenario, a significant amount of this power is being distributed to PoE devices, and this heat is dissipated at the remote location *Not at the switch* (The PoE device will dissipate head where the PoE device is, or in cabling between the switch and the PoE device) 

A good way to do calculations for this stuff, is to actually measure power consumption from a few switches at expected load, and work out PoE draw. Taking numbers from data-sheets can lead to ludicrous over-estimation of cooling (& UPS power/generator) requirements. I have seen communications rooms with 10-fold more cooling (& UPS) capacity than required, purely because they worked off power supply stats rather than actual application & load values...

To give you an idea, a 3750-48PS has a 540W power supply, but with 24 ethernet ports connected and no PoE it's only drawing 70W - That is nearly a 1000% over-estimation in power consumption if you go purely off your PSU statistics. It gets even more misleading (for local cooling, but not UPS) if you hook up PoE gear, as your power consumption goes up, but the power/heat is transported out of the room to a remote device!

Spend some time doing the cooling calculations, with real world loads! It's not going to break your connectivity, it's just going to be expensive! :)

[Chris0007]

Discussing the heat generated by Cisco switches and the HVAC (Heating, Ventilation, and Air Conditioning) calculations associated with them is a crucial aspect of network infrastructure management. Cisco switches are known for their reliability and performance, but they also produce heat during operation, which must be managed effectively to maintain optimal operating conditions.

Proper HVAC calculation is essential to ensure that the environment in which Cisco switches operate remains within acceptable temperature ranges. This involves considering factors such as the number of switches, their power consumption, the size of the room or data center, and the existing cooling infrastructure.

By addressing the heat generated by Cisco switches and performing accurate HVAC calculations, organizations can prevent overheating issues that may lead to equipment failure or degraded performance. Additionally, efficient cooling solutions not only contribute to the longevity of the switches but also help optimize energy consumption and reduce operational costs.

In conclusion, understanding the heat generated by Cisco switches and implementing effective HVAC calculations are fundamental steps in maintaining a reliable and efficient network infrastructure.