Like our power system, we provide a 100% uptime service level agreement on our cooling systems, because we've designed and tested them to that standard. Our cooling systems are designed to the same reliability level as our electrical infrastructure -- they are fault tolerant and concurrently maintainable. As with our power systems, the N-MatrixTM infrastructure management system provides full-spectrum, 24x7 monitoring and control of the system, overseen by our Operations Control Center engineers.
RagingWire's critical facilities engineering group designs our HVAC systems and our data center floor space to be as efficient as possible. Our cooling system is designed to be as efficient as possible during all seasons and all conditions, including airside and waterside economization, adiabatic humidity control systems, variable frequency motors in all cooling pumps and fans, and intelligent, automated system controls. Chilled water piping is located beneath the data center raised floor and at least 21-foot-high ceilings provide a buffer of cool air at the rack level that is maintained within ASHRAE standards. Hot and cold aisle configurations are strictly enforced in our data centers, with hot aisle containment in order to maximize efficiency. These measures and more allow us to cool over 225 watts per sq. ft. or 18 kilowatts per cabinet at our data centers. That's enough cooling to accommodate today's high-density infrastructures and tomorrow's as well.
RagingWire's Sacramento data center campus cooling system features a centralized, water cooled chiller water plant with up to N+5 computer room air conditioning (CRAH) units, onsite fresh water wells, redundant cooling loops, and multiple cooling towers. Waterside and airside economization cooling modes are used extensively at the site to increase efficiency.
Our Ashburn data center campus features a centralized chiller plant with air cooled and water cooled chillers. Custom built, high efficiency 100-ton CRAH units are located in separate mechanical chasses off of the data floor. A reclaimed water loop and onsite well will be available for our evaporative cooling towers, as well as waterside economization. For about 60% of the year, we are able to use free outside air (airside economization) to cool the data center.
Using such efficient cooling system design and operation, we reduce both floor space and power costs. Our energy efficiency initiatives have led to U.S. EPA ENERGY STAR ratings at both our Sacramento, CA data centers as well as reducing annual power consumption by over 9 million kilowatt-hours, a significant contribution in our endeavor to be environmentally responsible.