Anti-Freeze in Holding Tank

[Cracker]

I know that it's Summer - and certainly no one is thinking too hard about Winter - but I do have a question. How much RV-type antifreeze would it take to keep a 50 gallon holding tank from freezing up ---- say when "full" just to make the question more challenging. This does not pertain to an Airstream but, rather, to a commercial mobile kitchen unit that might be used occasionally in sub-freezing weather. The antifreeze could be poured directly down the units kitchen drain to set things up. Even if if took 10 gallons of antifreeze it might still be economically feasible. The alternative, of course, is to enclose the holding tank and provide heat.

[eubank]

Ah, a whoooooole lot of it. We've had folks with uninsulated/unheated tanks who tried to make it with the pink stuff up here during ski season. They were unsuccessful, and their rigs suffered the consequences.

The problem is that the pink stuff is supposed to be used undiluted (making it very different from automotive antifreeze, which you should never use).


Lynn

[85MH325]

Heat the tanks. It's the only safe way to use them.

Roger

[markdoane]

The pink RV antifreeze is about 30% propylene glycol. Full strength it will protect you down to about 7F.

If you were to mix it 2 parts water to 1 part antifreeze, it would protect you to about 26F. Not much protection.

If you can get a hold of 50%PG and mix it 3:2 (final concentration 20%) you would be good to 18F.

Better get a small heater and some duct tape.

[Silvertwinkie]

The tanks should be heated and insulated, but also some RV antifreeze should keep you in good shape.

[Cracker]

OK - that's the answers I was looking for! I just came across a "tank heater" in one of the RV parts catalogs that looks like a better way to go. Seems like a simple enough installation and if I also enclose the tank and provide insulation it should do the trick. The tank heater I'm looking at works on 110v and 12v. The 12v should be OK as long as the TV is hooked to the trailer with the engine running - but I'll bet that it would kill a battery awfully fast otherwise!

[NCMtnStream]

Originally Posted by Cracker

OK - that's the answers I was looking for! I just came across a "tank heater" in one of the RV parts catalogs that looks like a better way to go. Seems like a simple enough installation and if I also enclose the tank and provide insulation it should do the trick. The tank heater I'm looking at works on 110v and 12v. The 12v should be OK as long as the TV is hooked to the trailer with the engine running - but I'll bet that it would kill a battery awfully fast otherwise!

It may sound like a good idea and I am sure the dealership/rv center will indeed sell you the product BUT...I am sitting in a brand spanking new 20' FC with tank heaters built in by the factory. Sorry to say that even when keeping the unit at a cozy 70 degrees, interior doors and drawers open for air circulation, my fresh water tank is frozen.
If it is already winterized leave it that way. I was under the impression that a tank heater would work. They don't. At least not in the conditions we are having right now of a week below freezing point.

[bizetwo]

Hi NCMtmStream,
Did thand tankse factory put 110v&12v heaters on your tanks? or Are you just using the forced hot air being forced down between the floor and the empty space where the tanks are located?? Kind of curious to know as I'm thinking of puting the 110v ones on my tanks.
Thanks, Louis

[chaimemet]

AS is in deerfield beach a little east of Turnpike off of Sample Rd. Will go up to low 50s tomorrow and Monday but tonight , mon and tues near 34 degrees at night. At what temp does one have to winterize?

[NCMtnStream]

Originally Posted by bizetwo

Hi NCMtmStream,
Did thand tankse factory put 110v&12v heaters on your tanks? or Are you just using the forced hot air being forced down between the floor and the empty space where the tanks are located?? Kind of curious to know as I'm thinking of puting the 110v ones on my tanks.
Thanks, Louis

Both
The '09 FC came with factory installed 110v tank heaters for fresh and gray/black water. After the fresh water tank froze up I started to apply forced air heat by opening the cabinet doors and removing drawers.

[jcanavera]

Originally Posted by chaimemet

AS is in deerfield beach a little east of Turnpike off of Sample Rd. Will go up to low 50s tomorrow and Monday but tonight , mon and tues near 34 degrees at night. At what temp does one have to winterize?

Sounds like you should be okay. Early spring April, and late fall October, we have parked the trailer at home in the drive in preparations for going out. The trailer at that point isn't winterized. Typically we don't travel with much if any water in the fresh water tank. If the forecast is for overnight temps is near or below freezing, we will open up the cabinets to get air circulation around the water lines, and I'll set the furnace for about 50 degrees. I'll also turn on the water heater if it is full of water. We've never encountered any problems doing this. Sounds much like you can do the same thing and won't have any issues.

Jack

[Cracker]

I agree with Jack about using the furnace set at 50 degrees with the cabinet doors open. For the record, my son installed the tank heater on the holding tank discussed in the first thread above and it works great - even at temperatures below zero. I would worry more about the water pump freezing - which we've already experienced (---cracked housing.) The bottom of this commercial trailer is/was completely open. The holding tank bottom is still exposed but my son just had the remaining bottom of the trailer insulated with 6 inches of foam. Prior to that, he was also experiencing refrigerator problems overnight(---compressor too cold.) So far the fix is working great but operating a unit of this type in freezing temperatures is a real challenge! Now, a simple 1500 watt space heater on low (850 watts) keeps the interior around 55 degrees overnight. During the day, when the cooktop and fryolator are on, the 60" wide exhaust hood has to be on and the windows open. Operating under those conditions, with the associated wind chill, is not for the faint-hearted!