What Your HVAC Contractor Will Do
Your HVAC contractor will make his first appearance shortly after house framing is completed (dried-in, with roof).
At this initial rough-in, he will install furnace, air-handlers, duct work, and all major components that will go inside the house.
At this time, he should coordinate with your electrician on wiring requirements and location of electric panels.
High-voltage, heavy-gauge wiring is required for HVAC purposes.
Some HVAC contractors provide their own. Others expect the electrician to do it. Resolve this question in advance.
Exterior components (compressor) will come later at the final, when he also installs vent covers, and thermostats.
Types of Home Heating Systems
Oil Furnace
Gas Furnace
Read more about Heating and Air Conditioning...