Winterizing Air Conditioners

I just finished winterizing both of my 16,000 btu a/c & heat units. In order to create a positive pressure head for the circulation pump I cut up a general purpose spray bottle. Placing it over the open end of the sea strainer I could pour in the rv anti-freeze. A helper then started one of the units as I poured in the anti- freeze solution. I taped paper towel sections over the unit discharge thru hulls to show if the pink solution had circulated thru the condenser coils. it took about 1 1/2 gallons to do both of my units and about 30 minutes of my time.
There’s a commercial version of this funnel available for about $75, mine cost $1.78.

I pump the pink through the overboard discharge until i see it come out the through hull underneath. It takes about 1 gallon per AC and is done in less than a minute.

Use a pump like this -

https://www.amazon.com/gp/product/B01BGZ9TXG/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

I just feed pink from a container placed above the thru hull to get some head pressure.

Rubber stopper, pipe to hose barb fitting inserted and a short piece of hose are all that's req'd.