Furnace shutdown from CO

John R. Hall

News item. Look what the police chief suggested "...we need a foolproof shut down system for furnaces..." Is such a "system" available?


JANUARY 29, 2005

A 10-year-old Plymouth (Mass.) girl died from carbon monoxide poisoning several days after the gas built up in her family's Plymouth home during last weekend's fierce blizzard.

Nicole Garofalo died early Friday at Massachusetts General Hospital, said hospital spokeswoman Emily Parker.

The girl was one of three family members overcome by carbon monoxide on Monday when snow blocked the outside exhaust vent for the furnace.

Her pregnant mother, Christine Garofalo, was also overcome by the fumes. She remained in critical condition Friday at the hospital, Parker said.

Christine Garofalo's 7-year-old son, Ryan, has been discharged from the hospital, Parker said.

Leonard Garofalo, 38, a state Highway Department worker, had been plowing roads before he returned just before 11 a.m. on Monday and found his family unconscious.

"It's devastating," Plymouth Deputy Fire Chief Martin Enos said of Nicole's death. "This is hard on everyone, firefighters, ambulance workers, and police officers."

State and national fire officials, licensing authorities and industry experts met Thursday to discuss stronger safeguards in home heating systems, Enos said.

"Nothing will offset this tragedy, but we need a foolproof shut down system for furnaces to make sure this doesn't happen again," Enos said.

There were several carbon monoxide poisonings reported after the weekend storm, including two deaths in Boston.

Dave Yates (PAH)

sort of

John,

Something there doesn't add up. If that was a high eff direct vent appliance, the blocked exhaust should have tripped out the pressure switch & shut down the appliance.

Almost sounds like an 80+ model with an aux vent kit for sidewall application.

That's another advantage to utilizing properly installed and maintained direct vent appliances as the ones we've seen won't work if the intake or exhaust becomes blocked. The control boards on most units also do not allow the pressure switches to be jumpered out, which enhances safety and helps eliminate stupid half-way repair measures.

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Jack_21

Oddly enough

the very safest gas appliances are the vent free units. They do have an ODS (O2 depletion system) which will lock out the appliance when the 02 content gets down to about 18.5% from its regular 20.9%. There has not been a CO death on an ODS equipped appliance and there are millions of them out there operating. I'm going to check with the Gas Board on monday and find out what the appliance was. I'll post when I find out.

Mark Eatherton1

The loss of life is always tragic...

My thoughts to the survivors.

I'm afraid that an interlocked CO shut down system would result in way too many nuisnace lock outs, and would then be disabled, exposing the occupants to the potential CO poisoning all over again.

Maybe, one of these days, but none to the best of my knowledge at present.

There are CO sensors used to start exhaust fans in parking garages, but none fo interlock/lockout.

ME

Rich W

ODS

What exactly is an OD sensor? The last I knew, they were nothing more than a skinny thermocouple.I modified a CO detector and connected it to a solenoid valve. Gas logs, stoves,water heaters,wood fireplaces among other things also make CO. Too bad I don't have a rich uncle for the patent,UL approval, and whatever else the gov't requires. Atleast my family is safe.

Steve_35

Any ODS I've seen is nothing more

than a pilot with restricted air flow. You've seen the little holes at the base of the pilot? Block those with a little dust and the pilot won't stay lit.

Mark Hunt

How long


will an ODS last, and how do you test it?

Mark H

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Unknown

John Hall there is a system

produced by UltraGuard which shuts off the furnace and then restarts it when CO is dissipated.It can only be used with electrically operated equipment so it would not work on a water heater. It was advertised in the NEWS a while back. I communicate with the folks at Electronic Control Systems who are the manufactuerers and distributors. I am not endorsing this system just informing you about it. I do not have enough real world results and testing to offer my endorsement.

Jim Davis, Rudy Leatherman and George Kerr did not feel it was a good idea however. It uses a UL/2034 listing and the detectors are Bio-Mimetic Sensors versus electro-chemical sensors. George Kerr from Co-Experts and Rudy could give you some good insight as to what the problems are with this type systems.

If you need any information I can forward it to you. I have a complete kit in my center. There is also a new UltraGuardII which can monitor up to 20 detectors.

I have been experimenting with hooking up detectors in my duct system and releasing CO into the duct and using a switching circuit tied into the detector alarm circuit. I have not had very good results and have ruined five detectors in the process.

There is some discussion here locally about stopping all approvals on gas equipment until they have a safety shut off system in place.

Of course we all know that only gas equipment makes CO!!! sure we do, just kidding.

Unknown

Rich check this

site http://www.focalpointfires.plc.uk/ods/ there are some good pictures and an explanation of how it works.

Ken D.

Homer

Some years ago, I had a nighttime service call from a family that was not a regular customer. The reason they called was noise from a broken B&G circ. coupler. When I entered the house, it felt warm and humid but detected no other odors. I replaced the coupler and motor mounts and checked both the boiler and water heater for safety as per standard operating procedure. Had no draft whatsoever on either appliances due to a blocked chimney. I went upstairs for further investigaton. The woman told me no one in the house had been feeling well. I noticed she looked flushed and of course the windows were covered with condensation. After much cajoling (they were in denial) I called the Fire Dept. They took the whole family in for CO poisoning and ventilated the house. As previously suggested, it was probably the old loose and drafty windows that prevented them from dying sooner. If that circ. coupler hadn't of broken, they probably all would have died. Sooner or later these home centers and do it yourself outfits are going to get into some serious trouble by this so called free advice from clearly unqualified personnel. And by selling these appliances to people who don't have the slightest idea of what they are doing. Condensation on the windows indicates a very serious condition and this painter hadn't a clue. Incredible.

Unknown

Ken D and others

I am concerned for your personal safety. The job you describe, you entered the house, correct - did you know what level of CO was present? You could have ben overcome yourself. Always test before entering, get yourself a tester that tests for CO, Oxygen, and Fuel gases (natural and propane), the life you save may be your own.

Unknown

Oxygen Depletion Sensors

First let me say that safety is always my primary concern.

Having that said, these ODS devices ahve been in use in Europe for over 35 years with a minimum of problems.

How do they work? They are designed in such a way that if the level of oxygen at the pilot goes below 18% or so the flame will pull away from the quick drop out thermocouple (which will drop out in 30 seconds)and the pilot and main burner gas will be shut down (a normal thermocouple system can take as much as 180 seconds to drop out).

One of the products of complete combustion are CO2, if high levels of CO2 are experienced at the pilot this will also cause a shut down (due to lack of oxygen). High levels of CO2 can be caused by poor venting of the equipment. The equipment does vent by the way, INTO THE LIVING SPACE, this is not unusual as we also vent gas cooking equipment into living spaces and have done so for years. Let us get concerned that all gas burning equipment is operating safely and correctly, the only way we know that is to test the equipment. Remember a fully operating gas stove can be burning as much as 65,000 BTU's at a time with no dedicated vent to outdoors.

Now it may sound like I am defending unvented appliances, I am not what I want to convey is the need for due diligence.Customers are going to put these things in and it is our job to make sure they are working correctly.

Another feature on some ODS pilots is a bi-metal piece that is wrapped around the primary air opening on the pilot. As long as combustion is good, and the flame stability correct the bi-metal remains open. If the flame should start to float around and get down in the area of the bi-metal it will heat up and close of the flow of air to the pilot and it will pull away from the thermocuple and it will drop out again shutting down the main burner and pilot gas. These pilots are by design made somewhat unstable so that any poor condition will shut them down.

It is also required that unvented heaters only be used as a supplemental source of heat, they also are required to have large amounts of air for combustion and ventilation in the room in which they are operating. They also must have adequate clearances to combustible materials.

I do have a method for testing these which we teach at our training center.

S Davis

Tester

What brand of tester would you recommend?

S Davis


Apex Radiant Heating

S Davis

Tester

Tim what brand of tester would you recommend?

S Davis


Apex Radiant Heating

Unknown

I would recommend

a Bacharach Fyrite Pro Analyzer or a Testo 325M for combustion testing. A Bacharach Monoxor II, or Bascom Turner or Snifit for testing for Carbon monoxide.

I still from time to time use my old fyrite bottles just to check against my instruments.

Jim Davis_3

CO Shutdown Devices

A company called Quantum makes a furnace and water heater shutdown control. These would shut off your furnace and water heater if your oven made CO, your fireplace or if you had infiltration from your attached garage. Also Newtron Air Filters had a CO device built in to their air filter with a possible cutout. These devices measured high levels above 70ppm and could cause nuisance shutdowns.
Controlling equipment better so that it will shut down when it is not venting would seem the more logical approach. Today too many vented appliances are being built that can operate with a plugged vent or installations that are allowed that create the same problem.

Rich W

ODS

Thanks Tim. I can't believe all the stuff I've picked up from you guys. I'm a bit of a safety freak-good post all around. Thanks again.

Ken D.

> I am concerned for your personal safety. The job

> you describe, you entered the house, correct -

> did you know what level of CO was present? You

> could have ben overcome yourself. Always test

> before entering, get yourself a tester that tests

> for CO, Oxygen, and Fuel gases (natural and

> propane), the life you save may be your own.

Ken D.

Tim

You're absolutely right. I did think about that -after the fact. It doesn't take much to get yourself into trouble. One thing that was clear was the lack of any odors. Your suggestion of a CO detector at the ready is well taken. Any one of us can walk into a trap like that at any time. A complaint of just a simple noise lulls you into letting your guard down. And that is when disaster will bite-Hard.

Bob Harper

COSS

Superior Fireplaces used to sell a Carbon Monoxide Safety System with their lung vented appliances. BAsically, this was a cheap CO alarm hooked in series through an interrupter block to the thermocouple. They were a PIA! You got drop out from false positives such as hairspray or bathroom steam and voltage drop from poor connections.
****

The bi-metal choke Timmy described was used on some VF gas fireplaces but it was explained to me quite differently. Monessen Hearth Systems explained in order to get a quick, reliable ignition, the choke is closed, making the fuel richer but the flame a little wobbly. As soon as it heats us, the bimetal opens up to lean out the mixture and stabilize the flame. They, too clogged with lint and were a PIA. WE don't see them much anymore.
Timmy's explanation of an ODS is right on, as expected.

There's never been a documented death directly attributed to CO from an ODS equipped appliance since 1980, when they started tracking this. That doesn't account for all the other injuries, permanent effects, and faulty reporting systems we have. How about all the homes with severe mold?
There's more to this story...
Bob

Constantin

Thanks for the great explanation, Tim!

BTW, are kitchen ranges are limited to 65kBTU w/o venting? As far as I know, the ventilation is usually up to the consumer (do I turn it on?). As such, consider how the latest "prosumer" ranges have individual burner outputs of up to 15kBTU/ea.

Multiply that by 6 for your "average" 36" wide range and the consumer could be adding 90kBTU to the kitchen space, never mind all the combustion byproducts due to clogged or (my personal pet peeve) misassembled burners.

Some range hoods now have temperature sensors to modulate fan speed based on the heat that the hood senses. However, to the best of my knowledge said feature is not mandatory yet.

jerry scharf_2

Maybe more than 90 MBH

In the biggest burner contest the last time I wandered through a high end appliance store, I saw an 18K burner. You also forgot to add the 30 MBH oven.

The only thing saving people is that most of these are for show, and the people of the house mostly know how to call for reservations.

What I'm really envious of is the burners you see under the woks in chinese restaurants. They have quite a roar and look to have a 6" solic column of flame. Anyone ever work on one of these?

We are already at the point where the stoves have more burner capacity than the boilers in some houses. go figure.

jerry

Unknown

Bob Harper

I dug out my notesd on ODS pilot and you and I are both correct. On initial start up the bi metal is closed (or cool) as it heats up it opens. The correction for my definition is that if it cools (the bi-metal) from the flame being pulled away it will shut off the air to the pilot and it will go out.

Unknown

Constantin many new

homes (my son's new home is one of them) are putting in what I for years considered a commercial range. Six top burners at 12,000 to 15,000 BTU's each and a commercial oven at sometimes 30,000 BTU's add to that a wall oven at 25,000 BTU's that is potentially 127,000 BTU's to 145,000 BTU's in a kitchen. The fortunate thing is most of these new kitchens are very large wide open areas with lots of ventilation. They must however have a vent hood my son's id activated manually or by heat whichever comes first. It was interesting when the house was being built the inspector was discussing with us the equipment going in and it was his suggestion to have the heat sensor system installed with the range hood.

The thing you then have to watch out for is that when that range hood is running you can cause depressurization of the house. Fortuantely we have two Guardian air purifiaction systems bringing plenty of outdoor air in and equallizing the pressure.

jp_2

ok but,

where does the sampling come from? the room air or sampled from the burner?

as I said earlier, if room oxygen drops by 2% due to CO, CO ppm are in the thousands, so it must have to sample burner exhuast instead of room air??? thats got me confused!

Ken D.

Oh, by the way;

Every house or building that uses some sort of fossil fuel should have one or more quality Carbon Monoxide Detectors. They are as necessary as smoke detectors. Your lives depend on it.