Abstract: A rooftop cooling and/or heating unit may include, but is not limited to, a supply fan and a heating and/or coiling device. The cooling device is preferably one or more chilled water coils suitably mounted within the unit in-line with fresh air delivered via an air intake hood and/or return air supplied from the return air duct. The unit further includes one or more fluid circulation pumps connected in-line with the one or more chilled water coils. Embodiments of the rooftop cooling and/or heating units may further include one or more of the following: pump compartment, controls compartment, power compartment, space for optional features, varying air filter options, mixed air dampers, optional exhaust/relief features, etc. The unit may receive part or all of its power requirements from an associated solar power generator.