| 100 South 5th Street, Suite 2060, Minneapolis, MN 55402 | F: 612.354.2162 | T: 612.354.2442 | akfgroup.com |

November 3, 2016

Douglas A LuchtAKF Group, LLP100 South 5th StreetSuite 2060Minneapolis, MN 5402

To Whom It May Concern:

I have had the pleasure of working with Steve Sorensen for the past six months while he worked as anengineering intern at the Minneapolis office of AKF Group, LLP.

I have been very impressed with Steve and his approach to problem solving. I have found him to beresourceful in his abilities to complete assignments and been pleasantly surprised at his superb abilityto learn new software programs. He is careful, thorough, and diligent. He knows when to researchthings on his own and when to ask questions.

I will be sad to see him go but also understand and accept that his interests lay outside of the HVACconsulting industry. Should he decide to pursue a career with AKF, we would gladly accept him as afull time employee.

Very truly yours,

Douglas A. Lucht

AKF