Being an HVAC technician is a rewarding career. Techs can use their training in the field to solve customers' heating and air conditioning problems, and they can earn a decent living doing it. According to the United States Department of Labor, heating, air conditioning and refrigeration mechanics and installers earned an average of $21.69 per hour -- or $45,110 per year -- in 2015. With a little additional training, techs might be able to earn even more than this. If you're an HVAC technician, here are four kinds of training that may help you increase your income.

Specialist HVAC Training

Specializing in a specific type of HVAC work can help set you apart from HVAC technicians who have only general training in the field. Some projects require particular knowledge that fewer techs have. If you're one of the few techs in your geographic area who has specialized knowledge, you'll likely be able to command a higher salary because you have advanced training that employers taking on these projects need.

One of the best ways to prove that you have specialized knowledge in a particular area is to earn an HVAC certification in the specialty you want to focus on. Some areas you could specialize in include the following:

• residential or commercial HVAC systems
• electric, propane or oil heating systems
• heat pumps
• compressor installation or maintenance

Instructor Certification

Obtaining an instructor certification will give you many new opportunities to use your HVAC training. You'll not just be able to work for an HVAC contractor, but you'll also be able to consider job openings posted by HVAC training companies. Some of these jobs may pay more than the typical installation or repair tech position, and a teaching position will also let you spend some of your time in a classroom rather than hauling air conditioners and furnaces around.

If you not only want to increase your hourly rate but also want to increase the number of hours you're working, becoming an instructor is an especially good choice. Many HVAC training schools offer evening and weekend classes, so students can take courses when it's convenient for them to do so. Once you're an instructor, you can teach these courses and still work a 9 to 5 tech job.

Sales Training

Sales isn't directly related to HVAC, but taking a class in sales could significantly increase most HVAC techs' incomes. Some HVAC contractors let techs sell commissions, service agreements and even full systems. Often, companies that let their service techs sell these products and agreements provide a commission based on the value of the add-on, agreement or system they sell. For techs who know how to make a sale, these commissions can be a significant addition to their base pay.

How much additional income you may be able to make by selling items and services will depend on what your employer lets techs sell and what commissions they provide. If you can sell complete systems, the added income could be a lot. For example, the average cost to install a new furnace is $3,921. Even just a 5 percent commission on that would be $196.05.

Business Training

Taking classes on how to run a business will provide you with the best opportunity to increase your income from HVAC installation and service jobs. Instead of just getting an hourly rate and a commission when you sell something, you could work for yourself and pocket all the profits from any HVAC job you do. Of course, there are expenses associated with running a business, but you can still make good money running an HVAC company if you have savvy business skills. Over time, you could even grow your company, hiring techs yourself and making money on each job they do.