I've just found this ducting which can be run along the top of kitchen units: https://www.screwfix.com/p/manrose-...=Search-_-SearchRec-_-Area2&_requestid=948090. The website shows it in grey but it also comes in white which has a temperature tolerance of 40 degrees. In my kitchen it would need to run above an internal door - there are brackets available to hold it in place - then vent it through the outside wall. Any thoughts on this?