So since my coach ownership I really would prefer a alternative to the potable glycol (pink) to prevent system from damage. I use my coach year round but still want to be able to affordably keep from freezing. Probably equally important to me is keeping it healthy which required more chemicals or completely evacuated of moisture.
I do have a Aqua hot and damage (Again) is not a option. So when I rebuilt the Aqua hot I studied its drainage system and up to date have been blowing it out with compressed air finishing with about 70 psi venting out the Aqua hot (hot) drain for about a hour till it stops dribbling. Yes it takes a hour. But I'm still concerned about being moist enough inside the pipes to cause algae growth.
Storage tank drain left open, no vacuum applied EVER.
I plan to continue blowing it out then the following evacuation
So my question/ or direction I want to go is vacuum evacuation. I see no reason the system wont handle having say 12-25 inches of vacuum pulled on it.
It may require a additional shutoff valve after the fill valve line. I'm confident it will be fine. I would apply the vacuum to the Aqua hot (hot) drain line from under the coach
Planning on using a air operated vacuum pump for a couple hours then going to a 115 volt vacuum pump for say 24 hours.
I aware I may have issues with water valves leaking air in because they are designed for water pressure. Will cross that issue if it happens. My cheap disposable vacuum pump actually is a old refrigerator compressor. There free and easy to get. Yes they are life limited.
Any input or comments ideas are welcome, just want to bounce the idea around
Scott
Do you think running the AH with the hot water lines open would evaporate the water in the coils if given enough time?
Absolutely heat will help with airflow but doesn't affect all the cold water half
Ideally it would be nice to drain and plug in vacuum and walk away for two days
I would be afraid that the potable tank would collapse, taking the earth with it.
I would be happy using polypropylene antifreeze.
You might want to try this:
Fill the potable tank with a water and bleach mix that is too strong to drink.
The tank must be shaken, not stirred.
Pump the bleach mix through the coach plumbing.
Drain the potable tank.
Close tank to pump value.
Disconnect the pump from the tank
Disconnect the pump from the coach plumbing.
Pump a small amount of polypropylene antifreeze through the pump; do not rinse.
Blow air to evacuate the coach plumbing.
Blow warm air, forever, to dry the coach plumbing.
Tim
I'm sorry but sometimes the least expensive way in the long term costs a little more than you like.
That $10,000 Aqua Hot boiler and the forced heat exchanger? Should be filled year round with a non-poisonous glycol and distilled water solution. It's what we run in industrial chillers to keep the cutting oil cool.
Everything else? Install bypass valves for the water heater tank, drain the hot water tank, and add some way to drain the expansion tank. Pump non poisonous glycol through the entire system and wait for warmer weather.
High temperature inhibited propylene glycol - Dynalene PG-XT - buy online store (https://www.dynalene.com/product/propylene-glycol-dynalene-pg-xt/)
These system are a little different. Yes they have ten gallons of boiler fluid or Texaco long life anti freeze. There is no water heater tank. Potable water is heated indirectly on the outside of the diesel burner/ boiler. It's really nice getting to use the coach year round. Next week are driving it into Vegas for my sons 39th birthday. We can load our entire family including my 99 old mom so she can attend also. Trust me the days of going anywhere with her without a bathroom are over. I get about three minutes till failure notice. The photo in this post shows the Aqua hot in it's normally installed position before insulated and boxed up. Gives a better idea of what we are working with. Also needing addressed if pink glycol is used Is carbon water drinking filter that would also need to be tossed. I've already parked and pulled out of storage three times this winter. Also got trips blocked in for January to Q and KOH in Feb.
Scott
Never ever apply a vacuum to a tank ever.
Yes I disinfect with bleach but would prefer to dry the lines completely.
Yes I drain the tank and leave valve open.
Understand that the problem is the water and if it's removed it's no longer a issue. I genuinely think evacuating the water out with the air is a really easy way to remove the potential problem in its entirety. Deleat all glycol use. Allow simple procedure to put back in service, fill.
So figuring out how to follow is always acceptable. I could just leave powered up and not worry about it also.
Currently thinking the vodka idea is the best resolution. Covers all the bases
Following. Does your storage unit have a 50 amp service? If it does then cant you just keep the heat turned on?
So drain the fresh water tank, 20 PSI air and one of those Schrader valve adapters for your water fill port?
There is always 190 Proof EverClear.
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Thought I had covered the air volume needed. 30 psi just blows bubbles threw the tubes and never actually clears it. At 70 psi still takes a hour
Yes it does. Covered outside cat. But still like not worrying about power failures. At least its out of the UV
So today when we got home i drained and back flushed the clean black and gray tanks. Transferred all the on board potable water to the gray tank and back flushed the black tank. Opened all the drains and hooked up potable water to my big air compressor regulated to 60 psi to the fill and blew air threw the entire system then finishing with all but the aqua hot hot drain open. Misting steam and spraying the remaining water. Out of the coils. Aqua hot was hot and was easy to see the moisture as steam exiting. Cycled the fill valve and shut off. Let it run for a hour and returned to zero moisture coming from drain. Reopened all the other drains to verify empty.
So in regard to your question, no I don't think without air or a vacuum causing a differential you would ever get enough water out of the coils to prevent damage during a freeze