HVAC is short for heating, ventilating, and air conditioning, which is a system used in indoors and cars for best comfort and convenience, i.e. by keeping the desired temperature. You will find the HVAC, or the Air Conditioners separately at many homes, offices, skyscrapers, and much more buildings or places that need the conditioned air as the air inside and around the places is uncertain, too hot, or too cold. If the temperature is let as it is, of course, the activities done there will be interrupted. For instance, if you learn English in a very hot room or very cold room, I am sure that you will not feel comfortable even you will not learn effectively, or the worst, you cannot catch the lessons you are learning.
Therefore, you will need the Air Conditioners or the HVAC for the effectiveness and success of your study, work, or any other activity done inside the rooms. If you need to buy the HVAC or Air Conditioners, you can purchase those devices that are available on the market with various names such as Carrier HVAC or Carrier Air Conditioners and many other brand names you may be so interested in. To search for more brand names, you can conduct a search on the Internet for best and fastest results.