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How to cut the hole when mounting a new Aprilaire Humidifier.

Question: It looks like I need to mount the Aprilaire 700 unit on my cooling coil. How difficult is this and how do I know if I am going to cut into the coil since I can’t see inside?

Answer: I mount many of the humidifiers on the side of the cooling coil all the time when I was doing installs. You want to make sure that you are on the sides of the coil and not on the ends. If you install the humidifier on the ends of the coil then it will restrict air flow to the humidifier. I always traced around the template making sure the template is level. You want to make sure your template is positioned high enough where you aren’t cutting into the drain pain of the coil. Many times I take one end of the cased coil off, or move the coil cover back away enough so I can see inside the coil. I have seen so many coils that I know pretty much where to cut and not to cut. I would suggest starting as high as possible on where you drew the cut out with the template. Since the coils are pointed away near the top it is unlikely you would hit the coil if you start drilling near the top. I drill a hole large, sometimes with a metal cutting hole saw or large drill bit (do not drill deep just enough to go through the metal) big enough to get my sheet metal shears started then cut a small opening so I can see inside the cased coil, so you can see where the coil is positioned. You can always move the template up if you are not in a good position for cutting. Best of luck!