Today it is possible to still learn the heating and air conditioning trade through an on the job program. Many of the large companies routinely offer these training opportunities, but competition can be extremely fierce. You must have a minimum of a high school degree, or the equivalent. Most of the on the job offers will be given to people who have some previous experience as a mechanic, maintenance worker or have prior experience in electrical work. If you do not have this type of background you can take some short courses in skilled trades at a vocational education institution or at a community college. These courses cover basic construction, electrical repairs or welding. You can even obtain certification in some of these areas by completing the classes successfully. When you armed with these additional work skills you greatly improve your chances of being hired as an HVAC trainee or helper.