Ken was a very pleasant surprise! Of course all AirNow personnel are extremely polite and courteous, but Ken was very thorough and tool the time to explain everything he was doing. We were very comfortable with him as he took his time to inspect our system and found all the problems we were unaware we had. Thanks to the warranty we have there was no cost to us to fix all issues, Ken assured us that everything was in top notch order but in the event if something did go wrong we could count on AirNow to come right away, regardless of time of night, Day of week or even holiday. Thank you Ken and AirNow for your great service. You have a very happy customer.