Winterizing A/C

[NYSail]

So winterizing the systems as boat will be hauled this week. So now adding a/c to the list of purges. Figured just like with the engine and fresh water hoses I would just put the feed into a bucket of anti-freeze, run the pump and watch the flow out. Any other "tricks" that may work better or cleaner? I heard of back feeding the anti-freeze through the water exit through hull fitting and watch until it comes out the bottom.... but would the pump stop the flow?? Thanks!

 

[Doug4bass]

I use a hand pump to back flow the antifreeze from the pump "exhaust" thru-hull and pink stuff exits the intake. Works good.

 

[Parsons]

I close the through-hull and run it 'dry' first, then I remove the hose from the intake through-hull and put it in a bottle of pink-stuff (pure propylene glycol -50F), set the thermostat for 5 degrees under the current temperature, and watch it empty the bottle. My partner stands on the opposite dock to yell when it comes out the outlet pink. I then send another bottle through to make sure of the concentration. I figure at $5 a gallon, I can afford to waste one to make sure the cooling circuit and pump don't freeze. The outlet through-hull is so low to the water that I can't sample and test with a refractometer, so this and the waste system are areas where I plan to use an additional gallon for safety.

I guess that the 'backflow' method might work as my pump is centrifugal, not displacement, but what does that save you? Can you get to the outlet and apply pressure from the outside of the boat, or do you still have to remove a hose from a through-hull?

 

[Rich Stidger]

I winterize just like my engines, except that I use the RV antifreeze if I don't have the PE glycol available. I have an adapter that I made for my Groco raw water strainer that accepts a garden hose. I fill a 5 gallon bucket with fresh water and run the A/C for 5-10 minutes to completely dissolve and flush out any salt deposits. Then I swap the hose to another 5 gallon bucket with the antifreeze. Years ago I installed two shut-off valve in the lines going to each A/C and I add the antifreeze to each on in turn. In this manner I don't pour antifreeze out of one while waiting for the other to begin to show color. I figure it saves on antifreeze as well as having my spotter on the outside having to watch just one outlet at a time.
The pictures below show my generator in play, but the same system is used for the A/C. The last picture shows the A/C with the two shut-off valves.

 

[quadrille38]

Take a look in the archives. I know I've posted on this topic as have many others.
I think you will find extensive discussion that will be helpful

 

[NYSail]

I winterize just like my engines, except that I use the RV antifreeze if I don't have the PE glycol available. I have an adapter that I made for my Groco raw water strainer that accepts a garden hose. I fill a 5 gallon bucket with fresh water and run the A/C for 5-10 minutes to completely dissolve and flush out any salt deposits. Then I swap the hose to another 5 gallon bucket with the antifreeze. Years ago I installed two shut-off valve in the lines going to each A/C and I add the antifreeze to each on in turn. In this manner I don't pour antifreeze out of one while waiting for the other to begin to show color. I figure it saves on antifreeze as well as having my spotter on the outside having to watch just one outlet at a time.
The pictures below show my generator in play, but the same system is used for the A/C. The last picture shows the A/C with the two shut-off valves.

I like that fitting you have for your strainer.... would like to find something like that for my beneteau strainers to eliminate the need to remove hoses.
Will check archives.... thanks guys!

 

[SG]

I use potable antifreeze for my heads, AC units, raw water washdown, and my water systems.

I shut the through hulls on the AC units. Then I clean-out the strainers, fill them with anti-freeze until t comes-out the discharge and turn the unit off.