compressed air to prevent pipe freeze

[big bubba]

sounds like an effective method. i'll start out at lower pressure as it will purge a tankless & don't want to disturb any sensors, etc. prob 20-30 psi. water pressure is around 50lbs max. it's a short run under the sink. this thread helped out a bunch. regards

 

[Willman]

Fire suppression systems in warehouse freezers are air charged until the sprinkler head links are melted (or hit by a forklift!) you get 10-20 seconds of gushing air followed by the water
I worked in meat processing plants, seen it happen