 ensure that you have enough racks to support all the equipment you've bought. Power and Cooling Requirements This is a good time to work out your power requirements. Most vendors list the power consumption of their equipment on their web pages. Simply find out what kind of power the devices require (AC/DC, voltage, and amperage) and the connectors needed, and add up the requirements for each rack. Talk with the person responsible for the environment where your racks are located, and make sure that it can support the equipment you're putting into your racks. Chapter 35: Designing Networks Rack #1 Rack #2 Rack #3 Rack #4 Internet HQ-Colo Core-1 Core-2 Figure 35-6. Bay face layout Just because you can fit forty 1 RU servers in a rack doesn't mean you can power them! The default AC power installed in a rack in a colloca- tion facility is often two 20-amp AC power strips. If your 1 RU servers each draw 2 amps and have two power supplies, you can only install in each rack. If you want to add more, you'll need to order extra power, which costs more money. You will also consume more cooling, which may also cost you more money. Don't forget cooling requirements, either. Along with power specifications, vendors will list the British Thermal Unit (BTU) values for their devices. The person responsible for the environment where the equipment will be installed will also need to know this information. Even though you can physically install two 6509s in a rack, the required air conditioning systems to keep them cool may not be in place. To find power and heat values for 6500 switches, search Cisco's site for "6500 power and heat numbers." Because the power draw and heat output vary depending on the modules installed, you must figure out this information for each installation. The num- bers for the 6509-V-E specified earlier are shown in Figure 35-7. You should compile a similar spreadsheet for every device you will be installing. Documentation Environment Device Function Watts BTU/Hr Core-1 WS-C6509-V-E 9-Slot front-back airflo