A/C Copper Theft Protection A/C Refrigerant Line Sets Heat & Energy Recovery Ventilators High Velocity Air Handlers Grainger carries central equipment for the biggest central heating and air jobs in HVAC. When you need to create split-system ventilation for an apartment building, Grainger has the multi-position air handler as well as the ductwork you’ll need. You'll also find a high-efficiency gas furnace with the correct load calculation for any space. You can also find a replacement evaporator coil for a heat pump, plus the accessories you’ll need a refrigerant line, a tube brush and smoke matches to keep your big projects running smoothly. Grainger carries the central equipment for your most important heating and air equipment.Skip to main menu Skip to main content You are hereSBA.gov » Starting & Managing » Managing a Business » Running a Business » Energy Efficiency » Energy Efficient Upgrades » HVAC SystemsA computer room air conditioning (CRAC) unit is a device that monitors and maintains the temperature, air distribution and humidity in a network room or data center.