Ductless Ac Units Buying Goods In Canada And Bringing Them Across The Boarder To US?

Buying goods in Canada and bringing them across the boarder to US? - ductless ac units

Buy property in Canada and the United States placed limits
Long story short, you buy air conditioner ductless glands sclerosis in Canada for $ 800, $ 2700 U.S. shipping. I think about going to Canada in my car and the purchase of 3 units for personal use, not resale. Do I have problems at the border? Do they control what is in the van? Is there a document that I need to meet. Please be specific. Thanks