Defogging services are a bit like putting a Band-Aid on a leaky pipe—sometimes it’ll hold for a while, but you’re still dealing with a busted seal. I’ve seen clients get a year or two out of the repair, but once the seal’s compromised, moisture tends to sneak back in eventually. Swapping the sash is pricier upfront, but you’re not gambling with how long it’ll stay clear. Did you notice any difference in your energy bills after replacing the sash? Sometimes those foggy panes are hiding bigger insulation issues...
Funny you mention the energy bills—I didn’t notice a huge drop right away after swapping the sashes, but over winter it did seem like the furnace kicked on less. Maybe that’s just wishful thinking, but those foggy panes definitely made the rooms feel draftier. I dragged my feet for a while because of the cost, but honestly, I got tired of looking at the haze every morning. If your house is older like mine (built in the late ‘70s), sometimes it’s just one thing after another with the windows...