I was talking about dry contacts with one of my techs, and he looked at me like I had three heads—and one of them was on fire. So, I figured it would be good to cover the difference between wet and dry contacts in a tech tip. Basically, “dry” contacts are switches with no shared […]

Tech Brandon Livingston posted about fire dampers and took some photos shown here. He gave me permission to share this here, and his original post inspired this tip. Thanks, Brandon. The picture on the left shows the situation before the damper was opened. The right image show what happened after it was opened and a […]

This topic came up because I was testing out the new MR45 digital recovery machine. That machine goes off by itself when it hits a 20″ Hg vacuum. It's a cool feature, but it is good to know when that level of vacuum is overkill and when it's not enough according to EPA requirements. You […]