Alaskan Auger 140 hooked up to HVAC Ducting

Hello,
I’m new to the whole coal thing. I purchased the Alaskan Auger 140 with the 200lb hopper on the side. I was wondering what is the best way to hook it up the the HVAC ducting. The blower fan off the auger 140 is 1457 CFM and the one from the air handler is about 1600-1700cfm. The HVAC company came out and hooked the supply from the auger 140 to the supply trunk of the HVAC system and pulled the return from a hole in the floor from the first floor. They turned off the blower motor in the HVAC system and let the blower from the auger 140 supply the heat to the house. Will this work? Should they have pulled the return from the return duct instead of the hole in the floor to the first floor? Sorry for the long post. Any advice is appreciated!