Which certification type covers residential units and light commercial systems?

The certification type that covers residential units and light commercial systems is Type 1. This certification is specifically designed for technicians who work with small appliances, which includes refrigeration units and air conditioning systems typically found in residential settings and small commercial applications.

Type 2 certification, on the other hand, is focused on high-pressure systems and does not apply to the lighter residential and small commercial units that Type 1 encompasses.

On the other hand, Type 3 certification deals with the maintenance, service, repair, and disposal of low-pressure refrigerants, which again is distinct from the scope of residential units and light commercial systems covered under Type 1.

Universal certification includes all refrigerants and systems across all types but is more applicable for technicians who require the ability to work on multiple systems beyond just residential and light commercial, thus making it broader than necessary for the question.

In summary, Type 1 is specifically tailored for the smaller scale systems found in homes and light commercial facilities, making it the correct answer for the type of certification needed for these applications.