SKUTTLE Humidifier Flow-Through Under Duct<div style="text-align: left;"><strong>[Product Information]</strong><ul><li id="replacementPartsFitmentBullet" class="aok-hidden" data-doesntfitmessage="We're not sure this item fits your " data-fitsmessage="This fits your "><span class="a-list-item"><span id="replacementPartsFitmentBulletInner"><a href="#" class="a-link-normal hsx-rpp-fitment-focus">Enter your model number</a>to make sure this fits.</span></span></li><li><span class="a-list-item"> Tight houses have insulated walls and ceilings， Vapor barriers， weather stripping on doors and windows， snug doors， snug windows， and a fireplace damper. One-half air change per Ho </span></li><li><span class="a-list-item">  Average houses have insulated walls and ceilings， vapor barriers， loose doors， loose windows， and a fireplace damper. One air change per hour </span></li><li><span class="a-list-item"> Loose houses have no insulation， Storm doors， Storm windows， weather stripping， or Vapor barriers. Two air changes per hour </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/41-g8ce%2BKDL.jpg" noproxy>