District cooling systems provide a variety of benefits, both qualitative and economic. The qualitative advantages are perceived in terms of better comfort, better reliability, and maximized convenience. Mechanical cooling and air conditioning requirements are growing rapidly throughout the world, partly because there are many new buildings being built and partly because those buildings are being built in warm climates. However, no matter where those buildings are built, they tend to be tighter and more densely packed than they used to be. This creates a need for air conditioning even in very cold climates.