Lesson learned, about winterizing using blow-out method

[willald]

Well, temperatures here have started dipping down to freezing, so Saturday I had to officially end the camping season, and winterize the RV.

Anyway, I went through the usual procedure I use for winterizing - Remove water filter, run some antifreeze through/into the water pump, run air compressor to blow out all water lines, pour antifreeze down all traps/drains, etc. Have always used compressor blow-out method, and it works great for us.

Well, I'm finishing up pouring antifreeze in the bathroom shower and sink, when CO detector goes off. Cannot get it to quit alarming, sensing presense of CO in the RV. I open several windows, turn on bathroom fan, it finally quits. Turn off bathroom fan, a few minutes later it (CO detector) starts squealing AGAIN. I turn fan back on, let the fan run (with several windows open) for a good 20 minutes, CO detector then turns off, and everything is good.

At first I thought that this was a bad CO detector. Have had that happen before. However, the fact that after ventilating the RV for a while it cleared out....Well, seems there must have been CO present inside.

Oh, and no, the generator was NOT running, there was no gasoline engine running anywhere close by, no indication whatsoever of CO (and all gas appliances were turned off, gas bottles closed, shut off).

Soooo, apparently in the process of winterizing the RV, SOMEHOW, enough CO gas got in the RV to trip the detector. After thinking a bit, I realized what must have happened:

Air compressor was sitting in the garage when I was running it, when blowing out the lines. I run a long 100' air hose from compressor in the garage out to the RV when inflating the tires or winterizing. Compressor has always stayed in the garage.

I can only guess that there must have been some CO gas lingering around in the garage from when one of the cars pulled in earlier, and the compressor sucked it into its tank when running. Have been using compressor blow-out method for winterizing for years, and never had this happen before. But, makes sense how it could happen, when compressor's air intake is just a foot or so off the ground and inside the garage where the cars are.

Anyway, lesson learned from this: I think from now on when winterizing, I'm going to first purge the compressor tank of all air in it, roll it outside away from the garage, before turning it on. Hopefully that'll prevent any CO gas from getting sucked into the air compressor, and blown through the pipes and into the RV.

Has anyone that uses compressor blow-out method, ever had something like this happen? Any other ideas/theories on what may have caused the CO detector to go off in this case?

[JaxDad]

Now we've got two separate issues. Propane and CO.

Straight water vapour will set off a CO detector. Ethanol could set off a propane detector.

[tvchen]

JaxDad wrote:

ripperoo wrote:
Well I doubt that the propylene glycol caused any "fumes" as it has a very low vapor pressure.

Me neither..that's why I said plain old water vapour will set off CO detectors.

It is not the propylene glycol that is setting it off, rather it is most likely the ethanol in the antifreeze. The MSDS for the antifreeze I'm using contains up to 12% propylene glycol and up to 30% ethanol. I blew out my lines about a day before I put in the antifreeze so it definitely is not water vapour. As soon as I pumped the antifreeze through and opened the taps, the propane alarm went off (not the CO).

[JaxDad]

ripperoo wrote:
Well I doubt that the propylene glycol caused any "fumes" as it has a very low vapor pressure.

Me neither..that's why I said plain old water vapour will set off CO detectors.

[ripperoo]

Well I doubt that the propylene glycol caused any "fumes" as it has a very low vapor pressure. The following is from Dow's website; they produce propylene glycol. I could see the compressor accumulating CO and dispelling it into the camper easier than any of the other thoughts.

Environmental Information

PG is not volatile, and is miscible with water. Concentrations of PG in the air are expected to be extremely low because of its low vapor pressure. It is readily biodegraded in water or soil (via aerobic and anaerobic mechanisms).

If a spill should occur, PG partitions almost equally in water and soil. Relatively little will go into the air because of its low vapor pressure. PG is not expected to bio-accumulate and is considered to be practically non-toxic to fish and aquatic invertebrates on an acute basis except at very high concentrations.

[JaxDad]

willald wrote:
Has anyone that uses compressor blow-out method, ever had something like this happen? Any other ideas/theories on what may have caused the CO detector to go off in this case?

It wasn't CO. A compressor works by, well, compressing air. A standard unit will raise the ~14 PSI of atmosphere to ~125 PSI or about 9 times atmosphere. If the compressor is say 20 gallons, that means it contains about 180 gallons of air. For that compressor to have enough CO in the tank (aside from the fact it likely cycled at least once during the winterizing process) to set off the detector it had to be nearly toxic levels in the garage when it ran the first time.

It was almost certainly just water vapour from blowing the lines.

From the First Alert website "Alarms should be located 10 feet away from sources of humidity like showers."

Aerosol water will set them off very quickly.

[RobertRyan]

kaydeejay wrote:
While NOT toxic, the level of CO2 in the atmosphere has risen and is being blamed (in part) for global warming.

THAT is the science!

CO2 can kill you by aphyxiation. Many people have died in Africa from massive amounts of CO2 being emitted by plants in lakes.

[slickest1]

I have had the CO detector go off for no reason and after a couple times realized that the garbage can got pushed too close to it. It must of restricted the air flow around it and it alarmed. It has happened twice and we found a different spot for the can and have never had it alarm other then when I regularly check it.

[willald]

greatwhitenorth69 wrote:

mlts22 wrote:
One of my old habits with air compressors is to pull the ring so the tank blows itself out when done. This comes from the expensive Iwata compressors that are used in airbrush makeup work. Very precise machinery, but they do need to have the tanks emptied after a work session so there is no chance of water getting in the tank (there are water traps, but even then, any water going out the end severely screws up an airbrush job.)

I can easily see that happening though. It can be easy to position an air compressor near a generator's exhaust.

The thing with the "ring on it" as you call it is the PRV, it is usually mounted near the pressure switch near the top of the tank. You need a drain on the bottom of the tank to remove water from it. This is important to do unless you want the bottom of the tank to blow off from years of water sitting in it.

Yep, we're talking about the PRV, or pressure relief valve.

I agree its a good idea every once in a while to open the drain on the bottom of the tank (if it has one, some do not).

However, I also have to disagree with the implication here, that no water is removed via the PRV. On an older compressor I used to own, I remember when opening it, if it had been a long time since I had previously done such, I could feel some moisture coming out with all the air.

Will

[greatwhitenort1]

mlts22 wrote:
One of my old habits with air compressors is to pull the ring so the tank blows itself out when done. This comes from the expensive Iwata compressors that are used in airbrush makeup work. Very precise machinery, but they do need to have the tanks emptied after a work session so there is no chance of water getting in the tank (there are water traps, but even then, any water going out the end severely screws up an airbrush job.)

I can easily see that happening though. It can be easy to position an air compressor near a generator's exhaust.

The thing with the "ring on it" as you call it is the PRV, it is usually mounted near the pressure switch near the top of the tank. You need a drain on the bottom of the tank to remove water from it. This is important to do unless you want the bottom of the tank to blow off from years of water sitting in it.

[John_M1]

Glycol fumes?. Really?
I've never heard of such a thing.....

until yesterday....

I have been winterizing RVs with pink stuff since our first trailer in 1998, and have never had this happen.
Yesterday, we winterized as usual, emptying the low point drains first, and then pumping in pink antifreeze through a bypass on the water pump.
A couple of hours later I hear the LP alarm going off. If I hadn't started reading this thread yesterday morning, I would have thought there was something wrong with my RV or that I had done something wrong.
There isn't and I didn't, right?

[Dashonthedash]

willald wrote:

tvchen wrote:
Is your CO detector a combo CO and Propane detector? The propane detector is really a flammable vapour detector so any combustible hydrocarbons will set it off. Since you said that you poured antifreeze into the drains and if the detector is near the floor and anywhere near the drain it will set it off. The pink antifreeze that is safe for metal pipes will more likely set off the alarm more than the antifreeze for plastic pipes only as they contain a higher concentration of volatile hydrocarbons Once the volatiles dissipate then you should be good for the rest of the winter.

the detector is a combo, detects both CO and Propane.

..Now that I'm thinking about this...This is only 2nd time winterizing the RV we have now, as we bought it in March 2012. Last year when winterizing, the CO detector was disconnected, as it had gone bad a few weeks before and was going off non-stop. I got it fixed a few weeks after that.

Soo, this is first time winterizing this RV (Motorhome), with the CO detector hooked up and working as it should. And, indeed, it (detector) is at floor level, just a few feet away from the shower stall, where I poured a good bit of antifreeze down to protect the traps.

OK, so this may well have been vapor from the pink stuff, and not actual CO pulled in from the garage. That being the case, though, seems there's not really much I can do about it, except to just live with it when winterizing, or relocate the detector (not worth it).

Still, I would have thought if RV antifreeze could cause this, we'd have seen a LOT more posts from other folks having the same issue when they winterize.

Depending on the model, you can tell whether it's CO or LP/vapor by the alarm and, usually, which light is flashing. A propane/gas leak will normally cause a steady alarm, while CO will cause an on-and-off alarm (check your user manual). Combo detectors mounted near the floor, though, don't do well in detecting CO, which tends to rise, which is why you likely have another CO detector on your ceiling. If it is the anti-freeze, and you have a battery disconnect, simply engage it while winterizing. It will disable the detector.

[kaydeejay]

Bonefish wrote:

kaydeejay wrote:
Modern cars do produce hardly any CO, to the extent that the hosepipe thru the car window from the exhaust in a closed garage is no longer a successful way of committing suicide.

You better go back and check the science on this one. Cars still produce CO and CO2 in their exhaust unless you are driving an electric.

The science is that, since catalytic converters were introduced in 1975, the level of CO emitted from car exhausts is minimal. Converters were designed (in part) to burn the CO and create CO2.
I believe the current standard is 3.4 grams/mile or less, which is not very much.

Now if you are talking carbon DIOXIDE, that is a whole different animal.
These levels may be 500grams/mile or more and is directly related to fuel consumption. A highly fuel efficient vehicle may get this number under 200. Some European vehicles are under 100g/mile.

While NOT toxic, the level of CO2 in the atmosphere has risen and is being blamed (in part) for global warming.

THAT is the science!

[roy67ss]

It could be a bad or dying battery.

[Bonefish]

kaydeejay wrote:
Modern cars do produce hardly any CO, to the extent that the hosepipe thru the car window from the exhaust in a closed garage is no longer a successful way of committing suicide.

You better go back and check the science on this one. Cars still produce CO and CO2 in their exhaust unless you are driving an electric.