Ventless Fireplace Fumes

jp_2 · November 2006

Tim, when you tested(experimented) with ventless, did you monitor CO production with the reduction in O2?

I've always wondered where the CO numbers were when the O2 depletion sensor started shutting the unit down?

can you have drastical low O2 but very little CO?

thanks

Gary_15 · November 2006

Ventless fireplace fumes

I have a customer with a ventless two-sided fireplace installed in a wall between their living room and dining room. It's a natural gas unit, and I forgot to write the manufacturer's name down. The unit was in their home when they bought it last year, the age is unknown. On a separate issue service call to their home, they asked me to look at it. They tried using it last year but the "smell" fom it gave him a headache. When I lit it, it seemed to burn correctly, but there is a distinctive odor coming from this fireplace, and I have a bad sense of smell. The best way I can describe it is like a new piece of heating equipment when it's first fired off. But this has been lit numerous times just since they owned the home, who knows before that. Any experience with these units on The Wall? I don't usually work on them except to replace gas lines or ignitors, etc. I do not install them. This unit is totally vent free. I appreciate any comments.

Unknown · November 2006

Do a combustion test

on the unit as it may be making Carbon Monoxide. I hope they are not using it right now as it could kill them. The odor you may be getting is aldehyde which is caused usually by the flame impinging on a cooler surface. The result is that with aldehyde you definitely have carbon monoxide.

All fossil fuel burning equipment should be tested.

It is also a good idea to make sure that the unit is not overfired by clocking the gas meter to see what it is burning in BTU's.

Do you know how to clock a meter and determine cubic feet per hour and then convert to BTU's?

Edward A. (Ed) Carey_3 · November 2006

Vent Free Fireplaces

Gary,

Go to the link below, then click on the Fireplace section of the forum.

Search "Vent Free: or "Unvented".

I think that you will find the pros that post on that fireplace site do not think much of Vent Free Products. Myself included.

A person who has a vent free gas fireplace, "lives inside of a chimney".

http://hvac-talk.com/vbb/

Edward A. (Ed) Carey

Gary_15 · November 2006

Thanks for the suggestions, they are not using the fireplace and don't plan to unless we can figure out a solution. I do know how to clock a meter but have not done it up until now. I may try that.

Gary_15 · November 2006

Good link. I couldn't agree more. I remember walking into a propane dealership once where they had these working on display and I noticed the odor immediately. I think they're a bad design, no matter if the house is "tight" or not. I just received a call from a potential customer who wants me to give him an estimate on a Rinnai ventless heater and I'm reluctant to get involved in this. Seems like an open door to liability to me.

Steamhead (in transit) · November 2006

Run, don't walk

from these things. Not only are they a bad idea but they are ILLEGAL in some areas. I think they should be illegal everywhere. Yes, I know the newest ones have o2 sensors in them, but these things can fail.

My company does not install or service any vent-free equipment. The only thing we will do is rip it out.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Mark Hunt · November 2006

Clocking the gas meter

will tell you absolutely nothing so don't waste your time.

The only way to test this is with a DIGITAL COMBUSTION ANALYZER and if you don't own one, I would suggest you find a contractor that does AND knows how to use it.

You have a potentially deadly situation here and it doesn't sound to me like you are able to diagnose the situation properly. Not trying to insult, but your post about the flame "looking ok" and "clocking the gas meter" indicate that this is not a case that you should be dealing with.

Where are you located?

Mark H

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Gary_15 · November 2006

No offense taken, Mark. This is not something I work on. That's why I came to The Wall. And I have decided it's not something I'm going to get into. I've talked to some other heating service companies in my area (Central PA) and none of them touch these fireplaces, even though we all do gas furnace and boiler work, including combustion analysis. The majority of this work is done here by woodstove companies and their practice is to install it and walk away from it. I contacted one in my area and their suggestion was to tell the customer their house was too tight and they should crack a window in each room when using this fireplace.

Gary_15 · November 2006

Thanks for the confirmation-Our response to this and other vent-free equipment is "No thanks". This seems like a problem area we do not want or need to dive into.

Mark Hunt · November 2006

Gary

Give the folks at NCI a call, they may have a contact person for you in the area. 800.633.7058

You mentioned that the units were not being used which is a good thing. If possible, I would disable them until they can be tested.

Also, if you get a chance, try to get to one of Jim Davis's classes on CO and combustion. It will give you the info you need to solve issues like this PLUS bring in more revenue to your company.

Again, I meant no disrespect what-so-ever.

Best wishes!

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Edward A. (Ed) Carey_3 · November 2006

Good idea

Gary,

Sometimes the most profitable decision in a business is based on the decision "when not to do business".

You are a smart man,

Best Regards,

Ed Carey

jackchips_2 · November 2006

I'm going

to offer just a little different take, Gary.

It appears you are already in the middle of this by this being one of your customers and you did look at the appliance.

You should at least make known to your customer that the appliance installation must be verified to be in compliance with the manufacturers instructions, have the proper permits and have a CO test by a certified technician.

I would also recommend that they absolutely NOT use the appliance until the above is verified and that you do not do that type of service.

Do it in writing.

Jack

Unknown · November 2006

Mark calm down and stop

contradicting what I tell people as I am getting a little tired of that kind of thing here on the wall and it the reason I do not post very often.

My reason for telling this gentleman to clock those units is that there have been several cases recently of double sided unvented units coming from the factory with the wrong orifice size. So by clocking the burner he could find that out, change the orifice and then do his combustion test.

I think I was more than clear about not using the equipment.

Unknown · November 2006

Unvented Heaters & CO

I guess the consensus here is to shut off all unvented appliances as unsafe. Now please do not misunderstand me I would not put one of these in my house. I also believe they have the potential to be dangerous. The statistics do not however bear out our concern as to carbon monoxide incidents caused by unvented space heaters. There have been cases when they are improperly adjusted (screwing down on the regulators and over gassing them) that they have produced CO. I conducted some experiments on them several years back and proved they could produce CO and still not knock off the ODS pilot.

Now to my point, I would be very careful just arbitrarily shutting off something without a definite faulty condition involved. Just because you do not like them or feel they are unsafe. There are thousands of these out there. If local AHJ does not approve them all well and good shut them off. However if they are approved in your area I would be careful.

I would also ask all who read this post do you shut off gas cooking ranges that do not have a range hood. Most ranges burn as high as 65,000 BTUs to 85,000 BTUs on a double oven model. Many are not installed with provision to remove products of combustion and vent into the living space. They are by the way much more likely to produce CO than an unvented space heater. With that in mind how many of you actually test gas ovens when making a house call?

How about this lets shut them all off this week and we will have Thanksgiving dinner out!!!

Stirling Boston · November 2006

Did you say vent-less Rinnai?

I'm intrigued. Did you see any info on this?

Gas man_7 · November 2006

Vent Free ??

anything thats free comes with a price !!! First , please check with the Fire Dept , and the local Gas inspector ! as Mark and Timmy both know have to inspect vent free appliances in Mass. The wall is the best place for learning !! Bar none ! Working in service for a utility company I wouldn't touch the appl; other than make it safe if the owner couldn't produce the inspection tags ! Then i'd inspect the install myself ,if satisfied I'd consider repairs , MY opinion is they shouldn't be allowed in the first place , we've got too many do it yourselfers as it is !

Edward A. (Ed) Carey_3 · November 2006

Vent Free?????????

Gary,

Just in case you need some additional encouragement, see the links below.

Ask yourself as to why the one for the attorneys even exists, and you will answer your own question.

The second one is a proposal from the CPSC from 1978, but oddly enough it never was enacted. It is amazing how much power special interest groups can have on the powers that be.

http://www.anattorneyforyou.com/legal/ventless-fireplace.htm

http://www.classaction.findlaw.com/recall/cpsc/files/1978feb/78010.html

JMHO

Ed Carey

Gary_15 · November 2006

Yes, ventless Rinnai

They manufacture a line of ventless heaters both infra-red and convection from 2,000 to 30,000 BTUs. They claim a 99.9% efficiency.

Gary_15 · November 2006

THANK YOU EVERYONE!

This was the first time I seeked some advice on The Wall, even though I've been helped by it many times just by reading other people's posts. Your responses have been very helpful. What a great tool for all of us!
Gary Shimmel
Integrity Plumbing & Heating Service, Inc.
Mechanicsburg, PA

Bob Harper · November 2006

The Phoenix

The ventfree phoenix keeps rising out of the ashes. Please conduct a search of this site and HVAC-talk.com on these units.

I'll run through this again for the ump-teenth time this yr:

ventfree applainces are listed to ANSI Z21.11.2b as unvented room heaters. The codes are very, very strict as to when and where they can be installed based upon makeup air alone. Next, you have sizing guidelines, which are seat of the pants. No heat calculations, just the size of the checkbook. Installation- NFPA 211 calls for a Level II inspection before changing from one use to another yet it is almost never done. They don't even sweep it one final time so all that creosote rains down onto the unit clogging the burners.

Back to the testing: all to this point has been in vitro. There are no credible field studies of these units intalled into homes. Anecdotally, I think I've seen one in the last 14 yrs that I considered properly installed and maintained. The ANSI stds. allow for 200 ppm CO over the burner. That's under controlled lab conditions. I can assure you in the field, they are covered with pet hair, dust, spider webs, rockwool embers, creosote, rust, etc. I recently found one in a den ~12-16ft. into which they had moved granny in her hospital bed about 4 ft from the logs! 28mbtu burner with one door in and out and no MUA.

ODS pilots- these are highly engineered so the pilot flame speed slows as room O2 drops. Around 18-18.5%, the flame has advanced past the thermocouple causing dropout. The unit can pump out tons of CO and never drop out as Timmie said. The Ventfree Alliance points out there has never been a death attributed to an ODS equipped appliance. I wrote extensively about this phallacy. The reporting systems in America are a joke and wholly unreliable. The only true measure of failures is from the court room and good luck tracking these cases. Also, the reporting does nothing to distinguish CO related illness from every other malady. How much Prozac has been prescribed for people with chronic low level CO exposure? How many people think they have allergies when it is NOx? How many fires were caused by VF logs installed into fireplaces with profile gaps behind the facing?

If you believe the in vitro testing and computer modelling on the effects of VF on room Rh% and mold, they look wonderful. Do yourself a favor and get some anecdotal evidence of your own.

As for the odors, you may have aldehydes and therefore CO so combustion testing should go without saying. Understand, with no vent, any airborne compound that hits the flames or hot surfaces can make funky smelling compounds. I can smell as I enter a home with VF logs by the distinct odor when ceramic fiber logs are used. The starches and binders used to make these logs take forever to cook off. Also, the logs act as sponges absorbing odors from the air. You will never get them to stop stinking.

Last note: with see thru fireplaces, air currents tend to pass through the opening thereby distorting and cooling flames thus getting incomplete combustion and all that goes with it.

Let me ask the group, if you did perform a combustion analysis, at what numbers would you say or do anything? What would your test conditions be? Where would you sample, for how long and with what?

Unknown · November 2006

JP my testing was

not considered official as the gas company I worked for was not an official testing lab.

The results of my tests showed that with reduced venting of the units we could cause CO to be produced at levels of 200 to 300 PPM in the air above the unit. This is within what are considered standards (200 PPM the standard for max) With that level of CO the ODS unit showed no visual effects at all and remained operating at full pilot flame.
We had created this reduced venting by slowly lowering a large cardboard box down over the unit this caused recirculation of products of combustion back into the flame area quenching the flame. The box at that time was 6 feet above the unit. As we continued to lower the box at three feet above the unit the ODS pilot began to react. It took one hour for it to finally put the pilot out. The level of CO during this entire time stayed pretty close to 300 PPM. This was conducted in a room that was 20 feet by 20 feet (much larger than your usual room).

Another test we ran was to increase the pressure on the unit from 3.5" W.C. to 3.8" W.C. this was on a 30,000 BTU unit with a BTU content on the gas of 1050 per cubic foot. The orifice size in the unit was a 40-drill size. As the pressure was increased we clocked the burner and found we were now burning at around 31,000 BTU's. There was no change in the measure of CO in the area above the unit it was a steady 10 to 15 PPM. When we increased the pressure to 4" W.C. the input went to around 32,000 BTU's at this point the CO began to climb, in one hour we had a level of 400 PPM above the unit and the pilot was still stable with no affect on millivolts. Finally at 4.5" W.C. we had 34,000 BTU's on the unit and CO had climbed to 500 PPM and climbing at this point the ODS caused the flame to pull away and the unit dropped out in about 15 seconds.All of these tests were conducted in the same 20' X 20' room with normal air pressure in the room with a stable room temp of 70 degrees.

This same type of test was run on three different manufacturers units and the results were pretty much the same for all of them.

Ventless Fireplace Fumes

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