The sun radiates considerable energy onto the earth. Putting that relatively low-intensity (rarely over 300 Btu/h·ft2 [950 W/m2]) energy to work has lead to the creation of many types of devices to convert that energy into useful forms, mainly heat and electricity. How that energy is valued economically drives the ebb and flow of the global solar industry. This chapter discusses several different types of solar equipment and system designs for various HVAC applications, as well as methods to determine the solar resource. Quality and Quantity of Solar Energy Solar Energy Collection Water Heating Systems Active and Passive Systems for Solar Heating and Cooling Systems Cooling by Nocturnal Radiation and Evaporation Cooling by Solar Energy Sizing Solar Heating and Cooling Systems: Energy Requirements Installation Guidelines of Solar Thermal Collectors Design, Installation, and Operation Checklist of Solar Heating and Cooling Systems Photovoltaic Applications Design and Performance of Photovoltaic Systems Installation and Operation Guidelines for Photovoltaic Systems Symbols