I will jump in and concurr with frozen ocean. hvac/r is a career trade not just a job. if you are in it for the paycheque you will be disappointed, there is no guarantee of work or steady hours.
regarding the value of pre-employment or pre-apprenticeship, these were designed to be building blocks for potential apprentices.
what may be an asset to future employers is your current experiences ie. have you or can you work with your hands, do you know which end of the screwdriver to hold.
i did my pre-apprenticeship at bcit in 1980 long before jarts existed, it helped as an exposure to the basics of refrigeration. by no means are you leaving those courses with any skill that matters
to a potential employer. in this wired world we live in, in my opinion you don't need to go to a school to learn about the basics, its all on the web. hey remember that building called a library?
check them out, a lot of books available. also go to the wholesalers, RSL, WWG, Independent Supply, typically there are job postings and thats a good indicator work available.
for those first year apprentices, go to local488.ca, camp job on the dispatch board.