Petersburg has air conditioning and heating contractors. Air conditioning, done by HVAC (heating, ventilation, and air conditioning), is essential for contemporary societal comfort. Heating is necessary during the winter months for indoors, both at residential and commercial spaces. Air conditioning is done by using an air conditioning unit, which is a home appliance, system, or mechanism designed to dehumidify and extract heat from an are, using a simple refrigeration cycle. The entire system of heating, ventilation and air conditioning is known as "HVAC". Contractors are those to install and maintain these equipment. The fuel for heating can be of different types, such as electricity, natural gas, or wood fireplaces. Similarly, many different types and models of air conditioning units are available in Petersburg. A contractor would help you assess your heating and cooling needs. These units are rated for energy efficiency, and usually come with a warranty.