I am looking for a heating source to take the chill off out of a room. The house’s main heating system can’t extend to this area and electric heat is costly.
I am looking around for wall mounted NG unit either direct vented or ventless.
I came across the name Rennia in many advertisements. Are these unit any good? The cost of these units are equal to the Amish heaters and Edenpure. By the way, any opinions on the before mentioned units?
Thanks for any input!
Replies
Check local regulations to see if ventless are permitted in your area. Prohibited in many jurisdictions.
There is no such thing as a "ventless" gas heater.They all vent -some vent outdoors, some vent in your living space.
Choosing a "ventless" heater is like choosing to live inside your chimney
Lots of CO2, lots of (corrosive) moisture, and, if things o wrong, lots of carbon monoxide
Even without the carbon monoxide potential - not a good idea, IMO
"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
Edited 11/3/2008 10:39 am ET by rjw (BobWalker918)
Direct vent is your likely option, I think. Not familiar w/ the equipment you stated.
I'm not familiar with the brand name, but I strongly advise against using ventless appliances - they are just a bad, bad idea.
Justin Fink - FHB Editorial
http://www.rinnai.us/He'd spelled it wrong.They make ductless space heaters. I suspect that is where the confusion comes in. I'd hate to see one of your readers end up dead from CO poison gas trying to go ventless.
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We have a ventless fireplace in our basement that came in the house when we bought it. The key is in the definition of ventless. They are highly efficient at combustion. However, it's obviously not 100% efficient -- some gas and combustion leftovers will fill the air. They smell bad.
The Gas Research Institute (http://www.ventfree.org) has recommendations for sizing that are more restrictive and consider emissions. Consumer Reports indicates that if you don't use it a lot, provide extra fresh air, buy only a certified package, and use a CO alarm, you should be fine.
We've chosen to not use ours - it really stinks.
>>Consumer Reports indicates that if you don't use it a lot, provide extra fresh air, buy only a certified package, and use a CO alarm, you should be fine.And their ignoring (i) the other combustion by-products (including large amounts of water, slightly acidic) and the limited sensitivity of UL listed CO detectors and the need for low level detectors where there are vulnerable folks in the house.The Ventfree website is about as objective on CO as a political party is on political issues - take what they say with a large grain of kosher salt.
"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://www.cpsc.gov/CPSCPUB/PUBS/463.html
* All unvented gas-fired space heaters (manufactured after 1983) should be equipped with an oxygen depletion sensor (ODS). An ODS detects a reduced level of oxygen in the area where the heater is operating and shuts off the heater before a hazardous level of carbon monoxide accumulates. These heaters also have labels that warn users about the hazards of carbon monoxide.
* Always have your gas heater and venting system professionally installed and inspected according to local codes.
* Vented gas-fired heaters can also cause carbon monoxide poisoning if they are not vented properly.
If your space heater is meant to be vented, be sure that the heater and flue are professionally installed according to local codes. Vent systems require regular maintenance and inspections. Many carbon monoxide poisoning deaths occur every year because this is not done. A voluntary standard requirement provides that a thermal shut-off device be installed on vented heaters manufactured after June 1, 1984. This device is designed to interrupt heater operation if the appliance is not venting properly.
Be aware that older gas-fired space heaters may not be equipped with the safety devices required by current voluntary standards, such as an ODS or a pilot safety valve that will turn off the gas to the heater if the pilot light should go out.
To add to Dan's post.
The ODS is supposed to prevent the pilot from operating at an O2 level of about 18%.
In other terms, that means that there is 20,000ppm of something other than oxygen in the air.
Sounds like a plan to me.
Yeah, basically the oxygen in the air gets replaced with CO2 on about a 1:1 basis.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
Could also be CO, aldehydes or other nasties.
Edited 11/5/2008 11:12 pm ET by rich1
So long as the oxygen level doesn't drop too far there's little chance of CO. Of course any impurities in the gas (including the mercaptan) will burn and produce odors if nothing else. I can still remember the smell of a room with an unvented heater in it, though I haven't been in one for probably 40 years.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
Actually, it is easy for them to produce CO. Dirty burners, misplaced logs, wrong gas pressure, burning CO2, (the initial primary exhaust gas which is also a good fire extinguisher).
They are NOT to be used as a source of heat and most if not all manufacturers recommend that you open a window while using.
Things that make you go hmmmmmmmmm.......................
The safety devices on them are supposed to prevent those possibilities.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
Even IF the ventless were safe for the inhabitants of the house, the burning of 100K BTU's of gas will add a gallon of water to the house's envelope.
That multiplied by the number of hours of burn x the fireplaces rated capacity could calculate to a lot of water being pumped into a house and will result in some form of moisture problem that will damage the house. Mold, rot, condensate in the attic, sweating windows.
Those units also harm the house you live in.
In reality they do harm the people that live in the house too!
..............Iron Helix
Yeah, I certainly wouldn't advise them, except possibly for decorative fireplaces not used as a regular heat source.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
Actually, safety device is questionable. The oxygen depletion sensor is really not a sensor. It is a precise orifice in the pilot burner. It can get plugged with dust etc.
For most control guys, a sensor can be tested. You can't test these.
And again, at 18% O2, there are 20,000 ppm of something else in the air at that point.
Yeah, most of that missing 2% O2 is CO2, which is about the most CO2 it's safe to be breathing. It's not an ideal situation, but not an immediate health hazard.Again, probably OK for a decorative fireplace that's just used occasionally, not good for something used regularly for heat.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
>>decorative fireplace that's just used occasionally, Gas log sets are the worst, IMO.They are rarely installed with the logs in the correct positions and often there are flame impaction problemsJust about every gas log set I see has carbon deposits somewhere on the logs.And 9 times out of 10 (+/-) there are extremely high CO levels above those carbon marks.
"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
>>So long as the oxygen level doesn't drop too far there's little chance of CO. AND so long as there aren't any mechanical problems with the flame/burner.I've rarely run into a gas appliance producing high CO because of high CO2 in the combustion air - basically only where the combustion zone was 'sealed' and thus the unit wasn't drafting (Seen it maybe 4-5 times.)Senses observation-wise - such rooms get hot and stuffy - with visual indications of backdrafting (rust/scorch stains above the drafthood, wicked rust stains below the burners on in-shots)-- with test equipment, the draft problem is immediately evident - the flue gas CO levels seem to stay lowish for a bit, the flue gas O2 levels drop faster, and then the CO levels jump big time (get ready to pull you probe or plan on a sensor replacement!)Note- as I said, I've only seen a few, so I don't know if the above can be called a general course of events.
"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
>>* All unvented gas-fired space heaters (manufactured after 1983) should be equipped with an oxygen depletion sensor (ODS). An ODS detects a reduced level of oxygen in the area where the heater is operating and shuts off the heater before a hazardous level of carbon monoxide accumulates. These heaters also have labels that warn users about the hazards of carbon monoxide.Dan, I have very high regard for your heating knowledge - but I think some more thought is required for "ventless" heatersAn ODS is basically a pilot light sensor - if the O2 level goes down, the flame size goes down and the flow of gas is truncated.The ODS effectiveness is based on the idea that too much CO build-up will lead to oxygen depletion -- great idea if there isn't a lower area of the house that the heavier-than-air CO2 can sink to (and thus not build up at flae level) and it assumes any CO produced will stay in the room.Granted, significant CO2 build up is one potential cause of the flame producing too much CO - but that isn't the only way - and my testing experience indicates that nechamical problems with the flame are a far more likely cause of those units producing excessive CO.I tested a house with an ODS equipped "ventfree" with the staircase leading out of the room and a nursery right at the top of the stairs.I forget the CO levels of the flame - they were very high - I let it run for awhile (1/2 hour, maybe) to test for CO and CO2 build up in the room - didn't get any measurable/significant buildup - until I went up and tested the air in the nursery - it was well beyond 35ppm.BTW - there was a plug-in CO detector in the room with the heater - it was at standard outlet height and it didn't have a clue there was a life threatening CO problem in the house.Dealing with CO is simply a matter of common sense - as long as you actually think about all of the dynamics of the situation.And don't pretend that excessive CO2 (a natural consequence of venting the unit into the room it is operating in) is the only cause of CO.
"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
I was just quoting the relevant paragraph from the government web site.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
Ah, thanks for the link - I don't think I've seen that one before.I didn't have a chance to study it, but ....
"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
OK - but I think the information quoted is misleadingly incomplete
I would NEVER use a ventless heater inside any place I intended to sustain life.
Yes they sell them, but they also sell Ryobi tools.
Doesnt mean you should buy either.
Family.....They're always there when they need you.
Now that's funny.
"Yes they sell them, but they also sell Ryobi tools."ROAR!great line
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I put a Rinnai wall furnace in my family room.
I ordered it over the internet from a guy in Maine.
This heater is a big step up from the $150 non vented heaters they sell at the big box stores.
It is a quality piece of Japanese engenieering.
The unit vents to the outside through a double wall intake exhaust pipe, so no combustion fumes go into the living space.
" Ventless" must have been named by political people, it implies a benefit (no vent needed")- actually it can kill you and I think is illegal in some states -Mass and Cali??
Good point. I hate when things are named for what they are NOT.
They should really be called "interior exhaust" furnaces (or something similar).
"They should really be called "interior exhaust" furnaces (or something similar)."Sounds like a lady-killer after a long night preceded by lots of beer and chili.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
>>They should really be called "interior exhaust" furnaces (or something similar).Or "Turn-your-whole-house-into-a-chimney heaters"
"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
As for the Amish heaters ... they are being oversold as the big energy savers. While it is cheaper to heat individual rooms with such heaters vs. the entire house, they aren't magically more efficient than other heating sources. Their ads make them sound like miracle energy devices when they simply are not.
Still don't know about the Rennia (you spelling this right?). There are Rennai tankless water heaters that are popular in the domestic water heating arena.
We've got three Rinnai gas
We've got three Rinnai gas heaters at a place up in Vermont and we couldn't be happier with them. As someone posted earlier, they get combustion air from the outside air and they vent combustion byproducts to the outside so they are mounted on outside walls. The only downside I can see is if they are on a first floor outside wall in deep snow country, you have to make sure the snow does not cover the external vent fitting. They achieve this up at our condo by placing simple plywood sandwich-board type teepees over the vent fitting.