KINGSPORT – Installation of a new heating, ventilation and air conditioning unit on the roof of a medical office building at 135 ‚ West Ravine Road will require the Saturday morning closure of a segment of West Ravine from the intersection with Powers Street back to the Wellmont Holston Valley Medical Center entrance on West Ravine. Work is expected to commence at day break, with completion expected by noon on Saturday, May 3rd. A crane will be required to set the new HVAC unit on the building roof, requiring the intersection closure. A detour route will be provided.