lady has a two story wall of insulated glass panels set in framing with wood stops, which in heating season turns into niagara falls. . I know part of the problem is her heating system – high efficiency though unvented propane space heaters, which of course produce alot of moisture. I’d like to tell her to change that, for reasons other than moisture, but since we’re talking window sweat here, I wonder if that would fix the problem….
or would replacing the panels with better insulated (wider air gap?) windows work(please say no please say no…)
or how about adding a layer of glass…?
or how about…….a little help here?
Replies
You mean she has propane heaters that have no exhaust to the outside? Is that normal? I've never heard of such a thing. Seems like a disaster waiting to happen.
What's the climate like in this location? What direction do these windows face? Are the frames in good condition otherwise?
Al Mollitor, Sharon MA
>> Seems like a disaster waiting to happen.Is an unvented gas space heater any more dangerous than an unvented gas cookstove?
>>Is an unvented gas space heater any more dangerous than an unvented gas cookstove?Having tested a lot of both for CO production, yes.OTOH, having an unvented cookstove is pretty stupid, too.A stove doesn't get run nearly as much, though.And, FWIW, Thanksgiving and Christmas are said to be the 2 days with the highest hospital admissions for CO poisoning because they get the greatest stove use.I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace
I'm in the NW Arkansas Ozarks, so our winters are...generally mild, but with periods of extreme I've seen -20 in december and 90 in february...hard to dress right...
unvented propane heaters are common , and allowed by code except in a bath or bedroom, I think - they're supposedly 99.9% efficient, but you can sure smell that 0.1%, and they produce CO2 and water vapor. I agree with Mongo that they're a bad idea, no matter what they claim, so as I said, I'd like to talk this lady into changing them, regardless of the window sweat....
glass is southeast facing...I did some repair on the jambs and stops a few years ago, as they were poorly sealed when installed, so I think they're ok now; but the sweating is hell on the woodwork inside...
My opinion? Unvented combustion devices are a hazard. Moisture and pollutants...in a tight house...ugh.
Does she have a dehumidifier?
If the windows are leaky (jambs not foamed, etc) sometimes cold air coming through the wall can wash across the inside face of the glass and exacerbate the problem.
Imrpoving air circulation in the room can be a non-fix fix.
using a dehumidifier in the winter seems crazy, but maybe these heaters are just pumping vapor like mad...she should get a ...humidity meter? there's a name for those...
I thought of a fan also - worth a try...
Hygrometer.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Try what I do...wet your finger, hold it up iin the air, and count how long it takes for 63% of the water to evaporate off your finger.
You'll be able to tell, as the surface temp of your finger will decrease (due to the evaporation) by 1.9 degrees C. If it cools more than that, you've exceeded the 63% and you have to start over...but using a different finger.
Take the time it took, multiply it by 6, then if it's cloudy out, subtract one-third. If sunny, divide it in half.
Take that number, disregard it completely, and use the proper instrument to find the humidity in the house. Works every time.
Damn, I hadda use my toes, kept messing up.Actually a real simple one to make is nothing more than 2 venneers (about 1/4" wide x 1/16" thick x 6"long) of two different woods..Like Pine and cherry, glue them together with Contact cement..affix one end to a board so the strip is now laying slightly off the board, with the glue line facing to and away from the board..as the strip curls to te left or right of a center mark, the RH can be deduced..Calibrate by your finger method..LOL
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Yeah,
It seems counter-intuitive to go against the conventional flow, but the byproduct of those unvented heaters can be lots of unwanted moisture. Some are better than others, but based upon the symptoms...
Either take care of the source of the moisture, or try to even it out thoughout the house by moving the air around.
>>I know part of the problem is her heating system - high efficiency though unvented propane space heaters, which of course produce alot of moisture.
She doesn't have to worry about the condensation - she'll probably be dead long before the condensation causes a problem!
Note: so far as I know, NO unvented heaters are approved as a primary heat source; they are generally limited to a maximum daily use of 4 hours and they ALL require that a window be opened during operation (great feature for a device intended to heat in cold weather, right?)
And, fwiw, all comustion appliance produce a lot of water; high efficiency units just make it more obvious because the flue gas temps are lower so we're more likely to see it.
I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace
bob, where are you getting this information about the four hours, Not approved, etc.? I need facts to show people....
>>bob, where are you getting this information about the four hours, Not approved, etc.? I need facts to show people....
One spot is an article from JLC: http://www.jlconline.com/cgi-bin/jlconline.storefront/41a92c4500025b7c27177f0000010541/UserTemplate/82?s=41a92c4500025b7c27177f0000010541&c=de0f3a0bd6321355d3384c0cfc309c58&p=1Also, see http://hem.dis.anl.gov/eehem/98/980108.html#98010801And read the instructions for every "ventless" gas heater being sold.The US Department of Energy tells us:"most building scientists and indoor air quality professionals do not recommended ventless heaters in homes where moisture problems exist, or where small children and elderly persons live or where the heater is likely to be operated for more than 2 hours per day. Under NO circumstances should you ever install ventless heaters in airtight houses, mobile homes, or trailers."
http://www.eere.energy.gov/consumerinfo/factsheets/eb1.htmlIf you are in the Toledo OH area, drop me an email (click on my name to get to the email link in the Member Profile.)I have been certified by the National Comfort Institute to do "Carbon Monoxide and Combustion Analysis," and by the Building Performance Institute to do "Carbon Monoxide Analysis."I can also put you in touch with two of the countries leading authorities on carbon monoxide and combustion equipment.I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace
thanks for the links - very informative...do you think ventless heaters are ok in leaky old houses? do they produce CO only if burning incorrectly, ie., with an orange flame?
I'm originally from Toledo, family still lives there, but I been gone thirty years...visited this summer...you live there?
>>do you think ventless heaters are ok in leaky old houses? do they produce CO only if burning incorrectly, ie., with an orange flame?The old line: "an orange flame is a dirty flame, a blue flame is a clean flame and a yellow flame is producing CO" was only 1/3 right --- an orange flame is a dirty flame, rust on the burners, e.g.The only way you can determine the CO levels and combustion efficiency is with a CO meter/combustion analyzer.I have tested plenty of burners with a "picture perfect" blue flame with huge amounts of CO being produced.I have several concerns with "ventless" heaters.First - they do vent ... into the living space. Putting a ventless heater into a house is like choosing to live in a chimney.Second - the only "safety device they have is the "oxygen depletion sensor." It is nothing more than a thermocoupler which will shut off the gas if oxygen at the sensor drops too low - which would happen if O2 falls below about 20%. If it goes out of calibration (or was mis-aligned at the factory or knocked loose during shipping, installation or use, it might not do it's job.Or, a misadjusted burner could produce large amounts of CO, filling the room top down (flue gases rise, of course) or even rising into other parts of the house and the unit would continue functioning.Third - combustion heaters put out other by-products: corrosive water vapors, and all sorts of less than pleasant chemical compoundsThink of it this way: the ventless manufacturers keep telling us how safe they are, but they tell us not to put them in bedrooms, where we are most vulnerable.The Ventless manufacturer's trade assoc says:"when properly installed and operated according to the manufacturers instructions, vent-free appliances perform well within nationally recognized guidelines for indoor air quality, including emissions of carbon monoxide (CO) and nitrogen dioxide (NO2)."That's true, I suppose. It's pretty close to saying "when you are alive, you aren't dead."I haven't run across many ventless heaters which produce too much CO.And I haven't tested enough to form a statistically valid percentage of the one's which produce too much.In my opinion, one is one two many.I have disabled several in 4 years because of excessive CO. In one house there was a "window"/opening at ceiling level in the family room where the ventless heater was located; the "window opened onto a landing in the stairwell leading to the bedrooms. I don't have the exact figures handy, but the CO levels directly above the heater pegged my meter at 2000 ppm (which will kill in a few minutes) and after 1/2 hour burn (this was summer) the CO levels in the bedroom at the top of the stairs exceeded 20 ppm - at which point the levels in the family were so I had to stop the test.I am scheduled to testify in a civil case where I had tested one unit of a 2 unit building with only ventless heaters. The unit I tested was producing large amounts of CO and the landlord was notified of the dangerous condition and notified that ventless heaters may not be used as a primary heat source. He replaced the ventless heater in the one unit with a vented one, but not in the other. The people in that unit ended up close to death last winter from their ventless unit.The city attorney who is considering criminal charges.I don't like 'em.And .... I am close to Toledo.I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace
If you run the chemical formula for the combustion of propane or natural gas and convert from moles to real world equivilents you will find that....
For every gallon or therm burned (~100,000 BTU) there is a liquid gallon of water produced.
Total the the burn rate in BTU's/hour for this ladies "lethal heating system" , divide by 100,000 BTU to arrive at the gallons of water per hour added to the house environment as water vapor.
Your description as "window water falls" would be correct. Soon you will be able to call it the "rotten water falls".
Any inspection where there is an unvented heater receives a "HAZARDOUS WARNING" note in the report that I write.
Bob Walker is "dead on" about the hazards of these unvented appliances!
..................Iron Helix
thanks alot - now I'm really worried...I heat with wood, but use an unvented for back-up and when it's not quite cold enough for a fire(too lazy to make one) - live in an 1890's farmhouse with original windows, so tightness is not a problem, so to speak...last night the heater kicked on, and when one of the girls woke me around 2 am , my throat was sore and I had a headache...turned off heater...power of suggestion? anyway, I'm now looking for vent options...
also now have serious ammo to take to this lady...
>>last night the heater kicked on, and when one of the girls woke me around 2 am , my throat was sore and I had a headache..Could be. I did an inspection where, when I mentioned some mold in the crawl space, the client started gasping and panting.Of course, we had been inside the house for 2 - 2 1/2 hours before she suffered her reaction....If you're going to use a ventless, get and use a good CO monitor see the discussion that starts with msg 49763.1I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace