Hey people! When it's close to or below freezing outside my Heat pump kicks into defrost mode ( at least thats what the techs keep telling me ) where the flow of refrigerant is reversed. When this happens the copper line vibrates so much that i can hear it start at the H.P. ( located outside my bedroom wall ) and work its way along the floor joists and up through the house to the blower unit (not sure of the technical term..). The line runs about 20 feet along the floor joists and then up through a wall in my kitchen that separates the kitchen from the guest bathroom. The rattling is so severe that it shakes the glasses in the kitchen cabinets and you can feel it in the floor! I am told by the techs that they can install an anti-vibration device for around $200. Does anyone have experience with this? I am pretty handy and have considered cutting out the drywall and finding a way to either secure the line or to wrap it with something that will dampen the vibration. Thoughts???