Cabin getting tighter. Maybe need some ventilation?

[NM_Shooter]

My shack is at 10k feet.

I had a little bit of a scare on Friday night.  I had my coleman lantern going, and I was heating a big pot of water over my propane stove while I cooked a can of soup for dinner.  One of the burners on the stove went out when I turned down the flame, and I grabbed a lighter to re-light it.  I tried 4 different lighters and could not get them to start.  I went outside on the porch, and they all worked.  They would not work inside.  I suspect that my little cabin is now tight enough (with all the sheetrock up) that I burned off a lot of the oxygen in the cabin.  Oddly, my CO detector did not go off.  I would have thought that the CO would have been high before the oxygen was depleted to that level.

The lantern alone will heat the cabin to a point that I feel uncomfortable.

I slept with a window cracked. 

What are the chances that my cabin is sealed up too tight for safe sleeping by multiple folks?      These are cheap Lowe's slider windows that I have, and it seems as though they ought to be leaky enough.

[Pine Cone]

You might want to get a CO2 Detector/Alarm.  Pretty cheap insurance.  I'd leave a window cracked...

[rocking23nf]

never heard of this before, keep us updated with the outcome. It never crossed my mind until your post.

[OlJarhead]

Hmmm......

Being at 10,000 feet is tough enough of course, but if it were me I think I'd put in a hood vent for a stove (cook) and maybe a bathroom vent (shower).  While neither of these will directly be intended to provide air for the purpose of burning lamps or cooking they WILL reduce the tightness of the cabin and allow air to flow both in and out.

What kind of roof insulation do you have?  Is it vented?

I'm no expert but I'd say you might want to take a close look at your situation and perhaps research others who've done cabins up that high -- me personally?  I can't exist up there!  7500 feet is enough to make my eyes bloodshot!

[NM_Shooter]

I have a flat ceiling at 8' plate height, that has 6" batts above that.  Sheetrock all the way around. 

I may just have to leave a window cracked.  It is amazing how well a lantern can heat the place.  I may have to install a DC ceiling fan, as the heat settles high, and the floor can be cold.  Just waving around a towel can spread the heat around a bit.  I'm glad I didn't install a wood stove.  My whole cabin would be an oven!

You can buy a CO2 detector?  I didn't know that! 

[OlJarhead]

I have a flat ceiling at 8' plate height, that has 6" batts above that.  Sheetrock all the way around. 

I may just have to leave a window cracked.  It is amazing how well a lantern can heat the place.  I may have to install a DC ceiling fan, as the heat settles high, and the floor can be cold.  Just waving around a towel can spread the heat around a bit.  I'm glad I didn't install a wood stove.  My whole cabin would be an oven!

You can buy a CO2 detector?  I didn't know that! 

Roof venting?  Sounds like an attic with insulation on the 'floor' of the attic and open above?  Are their eve/soffit vents and roof vents?  The reason I ask is this can impact the way the house 'breaths' from what I understand reading a link John posted in the forums previously.

[NM_Shooter]

No eave vents yet.. only gabel end vents.

[Shawn B]

In a small building that is built somewhat airtight operating enough "appliances" that burn fuel, i.e. consume oxygen can burn oxygen at a faster pace than air can infiltrate into the small openings in the building. At 10,000' the percent of oxygen is already less than sea level or valley level. CO2, carbon dioxide,  is not poisonous, but it does displace oxygen which in extreme conditions can kill you. Remember we breathe around 21% oxygen, it does not take much of a drop for some people to show signs of low oxygen. CO, carbon monoxide IS poisonous and will affect you at a much faster rate, than CO2.

You might be able to buy a low oxygen sensor from a R.V. dealer 

Also do you plan to install a propane water heater or furnace ? If so make sure it is direct vent, meaning that it draws combustion air from the outside. If not you should install combustion air close to the appliance. One way to do this is, cut a 4" x 10" hole in the floor clear through to the crawlspace. Install a register with screen covering it to keep bugs out. If your floor is insulated, install a register boot and a short piece of pipe, get a cap cut then cut out the middle, leave about a 1/4" to solder some hardware clothe in there. Also you can do the same thing in the ceiling since your gables are vented. A 5" or 6" pipe will work fine in your situation.

Shawn

[Redoverfarm]

Frank you might take an extra battery for your detector.  I put mine in last fall and I think it has already been depleated.  I remember Mt. Don making the comment that the batteries will not last as long in a CO detector as they do in a smoke detector.  I will hold off on mine until I start burning some gas or wood which I hope will be another couple months.

[Shawn B]

Redover,

Due they make CO detectors that can be hard-wired with the smoke alarms ?

[Redoverfarm]

Redover,

Due they make CO detectors that can be hard-wired with the smoke alarms ?

Not sure.  You might go to "kidde" website and send them a question under "contact us" section.  For my cabin it is past the point to add any wiring with the open beam concept so I will probably just keep buying batteries. .

[Rob_O]

Redover,

Due they make CO detectors that can be hard-wired with the smoke alarms ?

CO is a heavy gas. Most detectors are designed to plug into a standard height duplex outlet. Get one with a digital display

[NM_Shooter]

I'll be using RV appliances.  The water heater is a 6 gallon Suburban direct vent.  My heater is a 15kbtu RV heater too.  The only thing burning in the cabin should be the stove / oven, and possibly a coleman lantern once in awhile. 

I think that whenever the stove is running, I'll need to make sure I keep the windows open. 

Good advice on replacing the CO / smoke alarm batteries. 

I'm still curious about normal respiration of 4 people in that box.  Seems like the windows ought to be leaky enough to accommodate us. 

My O2 saturation is a bit low anyway.  Here in ABQ it varies from 92 to 96 depending on if I am exercising or sitting around.  I've measured it up on my ranch, and when I am resting it is about 88. 

[MountainDon]

I have found that many (most, all?) of the butane stick lighters do not work very well at our cabin elevation of 8800 feet. The piezo spark ignition is not able to get the gas to ignite. If lit from another flame they will burn well. I think it may be related to a there being too high a butane concentration for the reduced oxygen at higher elevations; too rich a mixture in other words.  The worst offenders have been the so-called wind resistant sticks. I have a couple that work all the time down at 5500 feet, but will never work at 8800 feet.

A note: the oxygen content, as a percentage of the atmosphere, remains relatively constant regardless of the elevation. But because the atmosphere is less dense at higher elevations there is less oxygen available. This is why propane and natural gas appliances usually have jets that can be replaced for higher elevations. I have re-jetted the propane wall heater and refrigerator and adjusted the range. I've not touched the RV water heater as it usually sits there just running on the pilot flame and the high altitude jet for it does not change the pilot mix.

While I've not got a low oxygen sensor or alarm in our cabin, out of curiosity one day I borrowed a finger tip medical sensing device. I found a difference in my blood oxygen content of only 2 points after being in the cabin for a few hours at 8800 feet as compared to my base figure taken at 5500 feet. That was with "normal" appliance use; refrigerator on  (had been on running during a weeks absence) and some range top use for a meal preparation. We go back and forth a lot and spend enough time at 8800 feet that we seem to be well acclimatized to the higher altitude.

We do have a CO monitor/alarm. I think it is a First Alert model. It had good ratings from Consumers reports. It runs on AC and has backup penlight batteries. I use the Lithium type, they last a full year. I leave it plugged into the AC. When AC is available it automatically switches to AC. When the lights, etc. are off and the inverter idle, it switches to the batteries. The CO monitor itself does not draw enough to power up the inverter. It has a recording meter. After a 3 week period with the cabin left vacant in spring, but with the refrigerator left on, it registered 15 PPM on the meter when we returned. Mostly it shows no CO present at all.

The propane wall heater and wood stove are both fitted with exterior fresh air intakes. I have a kit to install for the refrigerator.

A note: CO detectors do not have as long a life a a smoke detector. Because of that I believe it is better to have 2 separate units. Replacing the CO detector every 5 years seems to be the recommendation.

[bayview]

   You may want to consider a fresh air exchanger . . .

http://www.centralairsys.com/ventilation.asp

/

[NM_Shooter]

Hey Don...

I found that my camper water heater would not ignite off the spark at 10k feet (near Big Meadows del Norte).  I fiddled with it and increased the spark gap and now it ignites fine. 

That was counter intuitive to me... I would have thought that a smaller gap would have had higher energy density. 

-f-