How not to use a CO sniffer.

[Richard Moore]

I just had a rather strange call from a previous client (I had inspected their new house 2 years ago). It seems that they had just had a HVAC guy in to service their 2 year old furnace. The tech took it upon himself to inform the clients that he was measuring “raisedâ€

[msteger]

That's what happens when someone gets a new tool and hasn't been trained on its proper use and how to analyze its measurements.

[hausdok]

2ppm is just about what you'd get in a house where a smoker is present or where they'd been cooking on a gas stove.

Sounds like they should call the HVAC firm and say, "Hey, just what the hell does all that mean, Bubba?"

ONE TEAM - ONE FIGHT!!!

Mike

[Richard Moore]

From the EPA at http://www.epa.gov/iaq/co.html .

Levels in Homes

Average levels in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher.

....

Standards or Guidelines

No standards for CO have been agreed upon for indoor air. The U.S. National Ambient Air Quality Standards for outdoor air are 9 ppm (40,000 micrograms per meter cubed) for 8 hours, and 35 ppm for 1 hour.

I obviously don't know exactly what the tech said but, equally obviously, it was enough (or too little?) to needlessly worry the couple into calling me.

[MechAcc]

Know what you mean.

Many years ago I followed up on a CO alarm that NiCor gas had dispatched on the NightHawk read +300 ppm. They shut off the furnace.

Turned the furnace back on. Checked the undiluted flue gas less than 30 ppm as I recall. ??????? Checked their water heater less than the furnace. Finally asked the home owner if they started and left their car in the attached garage during warm up. A training session about the dynamics of home ventilation pulling co from the garage got them to pull the car immediately out of the garage.

Despite the training efforts of manufacturers such as Bacharach and Testo and organizations such as National Comfort Institute and ESCO Institute and many others in providing training there are still large numbers in the hvac trade that grabbing a meter and measuring without training is the correct thing to do.