Run a thousand miles! It's been 8 years since these guys designed and installed ductwork for our addition. My office, on the second floor in the addition, is always cold in the winter and hot in the summer. They installed an Olsen furnace, which we have had nothing but trouble with. In the early days, it was because they didn't install it properly and we had numerous service calls. The furnace has had a terrible track record and has broken down once during the winter. We have now been told that Olsen is out of business and we cannot get parts. We also found that D&J did not install a new furnace or air conditioning unit, rather, they had installed year old units which they must have gotten cheap or had stored somewhere in a warehouse. We also found that the furnace and air conditioning unit are undersized for our home.