Vent free propane wall heaters?
doitall
| Posted in Energy, Heating & Insulation on
I welcome any and all input. I am finishing a couple of rooms in a pole barn to be used as hunting quarters (bunk room and kitchen room).
Have propane available, and was thinking of installing a propane wall heater. But, I am concerned about the ventless type (esp. in a sleeping area) even though the mfrs claim that they have an o2 sensor/shutoff. I would hate to have a malfunction.
Any opinions/suggestions? Any vented models available that you might recommend?
Thank you,
DIA
Replies
There is no such thing as a vent free heater. It is just if it uses an external vent or vents into the room.
I am not sure, but I don't think that they are apporved for use in sleeping areas.
Have you checked on direct vent (through the wall) appliances?
William the Geezer, the sequel to Billy the Kid - Shoe
What bill said: they aren't vent free, you're just choosing to live it its chimney.
And NEVER use one (i) as a primary heat source and/or (ii) as a bedroom heat source.
The "oxygen depletion sensor"(ODS) protects against one possible cause of carbon monoxide (CO) - which can kill - but there are other things that can go wrong with heaters to make them produce deadly amounts of CO
The ODS is basically a thermocouple. If oxygen levels drop in the room, the flame gets cooler and the ODS shuts off the gas flow to the burner. (Just like a pilot light works)
The ODS are mounted low in the unit, because the main concern is that people forget to open a window/door as an oxygen supply, and the large amounts of Carbon Dioxide (CO2) the primary byproduct of the combustion will build up at floor level (it is significantly heavier than other components of air) and start to block out the oxygen.
If the burner goes bad, on the other hand, the unit can produce huge amounts of CO. Co is basically the same weight as the other air components, and, because it is hot, it will rise and the ODS is completely happy.
I have tested a few "ventless heaters" where that was happening - in one case the CO was rising out of the room, into the stair well and collecting in the nursery at the top of the stairs.
Surprise, the infant had been sick ever since she was born.... (They were lucky she hadn't died.)
I have all sorts of training and certifications for Carbon Monoxide Analysis and Combustion Analysis.
"Ask not what the world needs. Ask what makes you come alive... then go do it. Because what the world needs is people who have come alive."
Howard Thurman
http://rjw-progressive.blogspot.com/
I have a blue flame heater in the shop that uses natural gas. The heater has five settings up to 32000 btu's. Keers the 600 sf shop warm at about the third setting ,probably 20000 btu's on the coldest days. I only have set the heater for 32000 btu's three or four times when the temperature was below 10°.
That being said, the directions warn you not to leave the heater unattended. Another words, use it while your up ,shut off when everyone goes to sleep. I leave the heater on pilot only when I'm done for the day. Only takes 15 minutes to get the shop up to 65°, then another 10 minutes or so to get the entire shop at about 72°.Sleeping bags will keep you warm at night when you turn the heater off.
So far after 8 years I haven't had any problems with the heater.If the pole barn isn't insulated then I would go with a cast iron wood or coal stove with a proper chimney.
The wall mounted heaters work well in an insulated building, worthless in uninsulated areas because they do not throw enough heat.
Make sure if you do buy one, have it propane ready. Some heaters are for gas ,some propane and others can be made to work with either fuel.
Along with the other posters, I would discourage you from using ventless heaters, especially if you're considering using them as your primary heat source.
The manufacturers, and fuel gas codes, specifically prohibit using them as the primary heat source.
The makers also say that they are to be operated with a window open, so there goes your efficiency.
The ODS is nothing more than a tipped pilot. When the oxygen level in the combustion air falls below 19 or 20% (21% is normal), the tipped flame of the pilot pulls back enough to quit heating the thermocouple, and the gas valve closes.
However, if the reason for a 1 or 2% drop in the oxygen level is because that much oxygen has been replaced with CO, you will never know it, because you'll be dead. 1% CO translates to 10,000 parts per million. 400 ppm is lethal in a very short time.
In fairness, these units have been subjected to extensive testing before they were allowed in the code, and I am unaware of any study that shows that death or injury resulting form their use is increased compared to vented appliances. (I would welcome any info from others to the contrary.)
Still...I would recommend real caution in deciding if and under what circumstances to use one.
>>In fairness, these units have been subjected to extensive testing before they were allowed in the code, and I am unaware of any study that shows that death or injury resulting form their use is increased compared to vented appliances. (I would welcome any info from others to the contrary.)I don't know of any studies.And I have tested a lot and the vast majority run fine.I have tested a few that put out huge amounts of CO.Wanna play the odds?BTW, for one I tested which was putting out very high CO, there was a CO detector in the room, plugged in at about 18" above the floor. The house configuration was such that the CO went pretty much straight to the second floor.
"Ask not what the world needs. Ask what makes you come alive... then go do it. Because what the world needs is people who have come alive."
Howard Thurmanhttp://rjw-progressive.blogspot.com/
Interesting.
And, of course, experiences like yours are probably not collected and included in the current body of information that manufacturers use to urge their products onto the market. So we end up with a possibly skewed picture of their safety. That's business--right?
>>And, of course, experiences like yours are probably not collected and included in the current body of information that manufacturers use to urge their products onto the market. So we end up with a possibly skewed picture of their safety. That's business--right?Yeah. I trained with Jim Davis at the National Comfort Institute.Fascinating guy - he does get a bit weird on some things, but his courses are real eye-openersA few years ago, I'd just bought a new combustion analyzer, mid winter. I happened to pass a "fireplace store" so I stopped in with the probe sticking out of my gym bag.I forget the reading, but it was well above the maximum allowed for entry to a building (35ppm) I think it was close to 100.I mentioned it to the sales man - he wasn't the least bit concerned.Ah well....
"Ask not what the world needs. Ask what makes you come alive... then go do it. Because what the world needs is people who have come alive."
Howard Thurmanhttp://rjw-progressive.blogspot.com/
Thanks one and all for the input. You reinforced my uncertainty with this idea. Since these rooms are well insulated, I now am going to shift gears and install some electric baseboard heat instead.The rooms will be used for a few weekends at best (hunting season), so the cost of electricity shouldn't be a deal breaker here.Thanks again, as always, for the prfessional advice and the responses to my question.DIA