I want to hook up a heatpump with a thermostat that requires lvt 8 wire. What is the right method of making the connections. I don't know how.

What gauge electrical wire do I use to hook up a heatpump. It's a commercial retail space in a mall.

I would use 18 GA on a commercial job. Watch out for plenum ceilings then you will have to use a plenum rated wire.

See here

http://en.wikipedia.org/wiki/Plenum_cable