I have read all posts below...what a mess.

I was searching the same solution. It is now summer and my door latch is failing prompting me to take it apart to diagnose. The internal components are full of condensation as the outside warm humid air leaks into the door knob opening and is cooled by either hardware or indoor AC temperature. My searches reveal that door hardware freezes as the door hardware becomes the most prevalent source of leaking air in a tight home.

Solutions I have found so far include small rounds of bubble wrap cut to fit, the idea for spray foam (was that yours? kinda sounds messy but a good idea to displace all air). I have not seen any solution for the thermal bridging aspect.

Consider hanging out on GreenBuildingAdvisor where more people are focused on these types of issues.

Have a great day.



On Friday, November 21, 2008 at 8:42:18 PM UTC-6, wrote:
Has anyone ever insulated a doorknob to keep the cold air out? I was
thinking about removing it, filling the hole with foam then cut holes
for the screws and latch. Wondering what other's opinions are.

Thanks,

Carl




http://www.gaihosa.com