Backup Heat Source- 100 pound propane tank?

Nevada · #21 12/24/08, 09:19 AM

Quote:

Originally Posted by 7.62mmFMJ

I paid $200 for the 10,000 BTU heaters I installed. They come equipped with the ODS (oxygen depletion sensor). And let me tell you, it was a bear getting it to stay lit.

I've heard that ODS can be a problem at high altitudes. They don't recommend them for altitudes above 4500 feet. I'm at 5170 and didn't have a problem. You may be at too high of an altitude for ODS to be practical.

PhilJohnson · #22 12/24/08, 09:27 AM

I used a 20,000 BTU vent-less propane heater last year with a 100 pound tank. It was very expensive and it didn't heat the house worth a darn. But then this was in 10 to 20 below temps in a drafty mobile home. Another thing was there was a lot of moisture in the air. I blocked off most of the house and the condensation in the cold areas froze making it look like the inside of a McDonalds walk-in freezer. I wasn't very impressed, and it isn't getting used this winter. Instead I think a waste oil burner would give off much more heat, be cheaper to run, and there is no carbon monoxide to worry about. There are plenty of plans out there on the internet for non-electric radiant waste oil heaters.

Nevada · #23 12/24/08, 09:29 AM

Quote:

Originally Posted by Rose

It's amusing that people get killed on a regular basis by generators when the power is out, but other blithely put unvented propane in their homes.

Big difference. Last winter I had difficulty starting my generator, so I rolled in up into the cabin to warm it up. After a few hours it started right up for me, but before I could get it turned off the CO alarm started sounding. It doesn't take long (perhaps 20 seconds) for a 6 1/2 HP generator to create dangerous levels of CO in a cabin.

While the problem is still with CO, comparing generator exhaust gasses to propane furnace gasses isn't valid. If the propane flame is adjusted to be blue, as it should be, there's almost no CO at all being produced (normally about 1 ppm, depending on flame quality).

7.62mmFMJ · #24 12/24/08, 09:44 AM

The declare in the documentation WHETHER OR NOT THEY ARE SAFE FOR USE INDOORS.

Shop heaters are not safe in the house.

Nevada · #25 12/24/08, 09:53 AM

Quote:

Originally Posted by 7.62mmFMJ

The declare in the documentation WHETHER OR NOT THEY ARE SAFE FOR USE INDOORS.

Shop heaters are not safe in the house.

Like one of these?

http://cgi.ebay.com/REDDY-HEATER-HD1...mZ150317546599

Yes, those are not safe to use indoors. I don't know that the combustion gasses are unsafe, but the tank itself isn't safe to be stored indoors.

7.62mmFMJ · #26 12/24/08, 11:21 AM

Perfect combustion is not assured in that burner.

It is also a severe fire hazard.

And, as you stated, having a 20 lb propane bomb in the house is not recommended.

Pink_Carnation · #27 12/24/08, 11:46 AM

A difference that you should note on propane stoves versus a heater is the length of time is is likely to run. As well as all the stoves I've seen would say not to use them for heat because of a build up of fumes.

When it is cold without power you might not have very much air exchange and that can cause even more build up than they expect.

Nevada · #28 12/24/08, 11:56 AM

Quote:

Originally Posted by 7.62mmFMJ

Perfect combustion is not assured in that burner.

I suspect that the combustion is satisfactory. It's a lot like the Mr. Heater flame, and that's for home use.

http://www.mrheater.com/productdetai...catid=41&id=24

I use one of those to warm the bathroom on cold mornings.

mdharris68 · #29 12/24/08, 11:56 AM

Quote:

Originally Posted by Nevada

I used to be a firefighter, and I was taught something similar. However, I'm also a chemical engineer (by both degree and trade). Therefore, when considering a furnace for my cabin I decided to look at the facts.

The fact is that propane burns very clean. While there is some carbon monoxide found in propane combustion gasses, it's not enough to create dangerous levels for humans. When a CO alarm is also used, you can be sure that the CO level is safe.

However, with an unvented furnace you need to follow a few rules.

Allow at least 50 cubic feet of volume for each 1,000 btu/hour of furnace heating capacity.
Do not place the furnace in a space that can be isolated with a door, such as a bedroom or bathroom, unless that room has the minimum 50 cubic feet for each 1,000 btu/hour of furnace heating capacity.
Be sure that your furnace is equipped with an Oxygen Depletion Sensor (ODS) that will shut-off the furnace if the oxygen level in the room drops below 18%.
Use a CO alarm.

Really, if you think about it you'll realize that a propane range is unvented and puts out about as much heat as a wall furnace when the oven & burners are in use cooking a large meal. Certainly, no one is afraid to use a range that's putting out the same combustion gasses that a wall furnace would.

I use an unvented 20,000 btu/hour wall heater to heat my cabin. The CO alarm has never sounded, and I've found the unvented wall heater to be entirely satisfactory for primary use. I certainly would have no problem recommending one for back-up use.

I'm not surprised that your propane installer told you that, but I suspect that he has had limited training in this area and has not researched the facts independently. He was probably repeating information that had heard, which probably had the confidence level of rumors, superstition, and wives tales.

The more you learn about it the better you'll feel about it.

Thanks for the list dealing with the oxygen requirements, and the oxygen depletion sensor. I was trying to find that info but couldn't come up with it.

Anyhow, I have installed a few ventless heaters for customers that asked me to, but once again, I don't recommend them, especially to anyone that isn't sharp enough to follow all of the guidelines and keep them clean and well maintained. And most if not all were for back up use during power outages.
As a side note, I have a commercial oven in my house that I had to replace the thermocouple on the other day, and I cleaned the burner and pilot. So after I did this, I turned on the oven and checked the CO level coming out the back vent, and it was at 93 ppm. (I have a single gas anylizer for CO that I use for work.) So I checked my gas dryer, and it was at 0 ppm CO level. My water heater was at 34 ppm. I am trying to figure out how my dryer runs so clean.

Nevada · #30 12/24/08, 12:06 PM

Quote:

Originally Posted by Pink_Carnation

A difference that you should note on propane stoves versus a heater is the length of time is is likely to run. As well as all the stoves I've seen would say not to use them for heat because of a build up of fumes.

When it is cold without power you might not have very much air exchange and that can cause even more build up than they expect.

We get down to -10 a few times each year here and the CO alarm has never been set off by the furnace.

Propane combustion gasses normally have about 1 ppm CO, but it's said that there are no negative health effects with concentrations up to 70 ppm. The CO alarm will sound at 50 ppm.

Alice In TX/MO · #31 12/24/08, 12:13 PM

Info from a propane gas company:

http://www.permagas.com/article_Vent...s_feb_2005.htm

"Yes, a propane heater without a chimney or vent is legal, but it may be dangerous. A ventless heater uses oxygen from inside your room to support its combustion, and can produce carbon monoxide in return."

From another source:

http://www.wisegeek.com/what-are-ven...fireplaces.htm

"Several states within the United States, as well as other countries, have completely outlawed ventless gas fireplaces because of health concerns. Canada, Massachusetts, and California don't allow people to install these types of heaters because of their potential to build up carbon monoxide, deplete oxygen, and lead to unconsciousness or even suffocation. Check with your local building code before purchasing one of these appliances.

A milder health hazard offers another disadvantage to this choice. Ventless gas fireplaces lead to an increase in the room's humidity. Burning gas or propane creates water vapor that can build up in a room and possibly lead to mold and mildew growth. If most forms of mold aren't truly dangerous, they will certainly increase allergies and could spoil fabric, photographs, and books."

From a heater seller's website:

http://www.alsheating.com/PropaneHeater.htm

"Very Important Notice:
Please do NOT call if you are looking for an UN-VENTED propane heater as that is NO different than going into your garage, shutting all the doors, starting your car and then laying down for a very long and permanent sleep - Good Luck!"

Nevada · #32 12/24/08, 12:52 PM

Quote:

Originally Posted by mdharris68

I am trying to figure out how my dryer runs so clean.

It's possible that the combustion gasses don't vent out the dryer vent. They could vent into the room.

Nevada · #33 12/24/08, 01:01 PM

Quote:

Originally Posted by Rose

From your first link:

Carbon monoxide is an odorless, tasteless gas and you may not know it is there until after it puts you to sleep. How much carbon monoxide is too much? 200 parts per million (ppm) can make you sleepy, 800 ppm can make you unconscious within 2 hours, and dead within 3 hours.

But if the alarm warns you if there's 50 ppm, and the alarm never goes off, then who cares what it does at 200 ppm?

Quote:

Originally Posted by Rose

Ventless heaters are required to have an oxygen sensor to detect a lack of oxygen, but they only work at the heater, not where you are sitting.

What on earth are they talking about?!

artificer · #34 12/24/08, 06:32 PM

An option that negates the entire safety isuue is the direct vent propane heater. Same no power thermostat. Same use of propane for backup heating. Only problem is that they cost about $450 vs the $100 for the ventless thermostat controlled heater. Those are the prices at the local Menards in Wisconsin. (I missed out on the $299 sale on the direct vent version)

As for them not heating much... they are only 10,000 15,000 or 20,000 btu/hr. Its not fair to compare them with a 75,000btu heater.

The ventless heater we purchased said it wasn't intended as the primary heat. The installation instructions also mentioned the amount of openings needed to supply cumbustion air. They also put water into the air, so the more you use it, the more water. In winter, a certain amount is helpfull. After that you get frosted windows, and other less desireable stuff.

If I had the money, I'd get the direct vent heater. You lose some efficiency, but don't have the safety concerns.

Michael

Nevada · #35 12/24/08, 08:31 PM

Quote:

Originally Posted by artificer

An option that negates the entire safety isuue is the direct vent propane heater. Same no power thermostat. Same use of propane for backup heating. Only problem is that they cost about $450 vs the $100 for the ventless thermostat controlled heater.

Actually, there are sometimes opportunities for vented propane heaters. There is a crew of guys around here who disappear old mobile homes for a living. The come across them sometimes. But as you said, you lose 20% of your heat up the flue when you vent.

Iddee · #36 12/24/08, 08:41 PM

I have used ventless 30,000 btu wall mounts for years in different houses and am not writing this from the hereafter. I think the scare on ventless heaters rates right up there with banning raw milk from the farm. Similar to New Jersey outlawing eggs that the yolk wasn't fully cooked.

PURE NONSENSE!

Simpler Times · #37 12/25/08, 12:49 AM

Thanks for everyone's input...esp about the expected burn time for a 100 pound tank, how the tanks can be/are commonly transported, and reassurance that others have used similar setups. I intend to use caution as to the safety issues. As I stated in my original post, the set up is intended for use to keep the house above freezing during times we are away from home. Wood provides our primary heat.

tamsam · #38 12/25/08, 01:27 AM

I guess we are lucky here. We use a 20,000 btu ventless propane heater for back up and have never had a problem. When we first installed it we used it for one month as a test to see how much fuel it would use. A 100 lb tank lasted 29 days and it was cold but not brrr cold. Temps were in the 20s at night. So far this year we have used about 30 lbs. Ours has an o2 sensor and will shut off if it runs low. We heat with wood and coal and use the heater for night use if we don't get up and keep the wood heat going. The old wood heater sure felt good this week with temps down to 6 and 8 at night. good luck with your heat. Sam

WisJim · #39 12/26/08, 07:53 AM

I have friends using various sizes of the Cozy heater, which is available in direct vent, outside combustion air models http://www.cozyheaters.com/products.php up to 40,000BTUs. Some models use no electricity at all, and they are popular with off-grid electrical systems.

No matter how safe an unvented gas heater is, a vented one would be safer, and one using outside air for cumbustion is safer yet.

Alice In TX/MO · #40 12/28/08, 10:17 PM

From another expert:

http://www.chimneysweeponline.com/hovfsci.htm