Combustion Safety Testing and Risk Elimination

Am I wrong or are health mandates, such as combustion safety testing and ventilation,  crippling home performance and weatherization? The American quest for risk elimination wastes billions of dollars annually.






For example last week, I walked into the Helena International Airport, which has only two jetways. At 5:30 AM there were 12 TSA agents screening travelers. The US  reaction to 9/11 and other such risk-elimination projects will hurt our economy unless we evaluate risk and act to control risk in a cost-effective way.


What’s the Risk?

Calculating risk is a 5000-year-old occupation related to insurance. The actuaries say that you can’t afford to reduce risk to zero. If the merchant’s risk-tolerance is zero, the cargo never loads and the ship never sails. My post on the topic of carbon-monoxide hazard related to home energy conservation began a conversation with readers about risk management. This post continues that discussion.

Three Big Risks

The risks of 1. global warming and 2. air pollution from coal-fired power plants is rising at a frightening rate. My guess is that more than one in 20 people worldwide  suffer respiratory illness, economic loss, hunger, or shortened lives from these two threats to say nothing of environmental destruction and species extinctions.

A representative of the Building Research Establishment (BRE) in the UK identified 3. cold drafty homes as the second leading cause of preventable death in the UK, behind falls, at the 2010 Healthy Homes Conference in Denver.  Home energy retrofits can mitigate these three risks at the same time that retrofits are reducing energy waste.

With global temperatures rising and whole countries blanketed in toxic air pollution, the weatherization and home performance community is handicapping its own effectiveness by adopting expensive and distracting health and safety mandates aimed at risk elimination.

Here is my guess of the chance of our technicians preventing a CO-related death. Let’s say that, after subtracting irrelevant CO deaths like generators operating indoors, there are 300 preventable annual CO deaths and 75 million households with combustion appliances. That’s about 1 in a quarter-million chance that any household will suffer a CO death in any year. Then let’s say that there is a 1 in 20 chance that a home has a serious CO problem and that a technician solves that problem. Now we’re at about 1 in 5 million chance of preventing a CO death. If our industry treats 250,000 homes per year that’s 1 in 300 homes with combustion appliances and now we’re at 1 in 1.5 billion chance of preventing a CO death.

My Belief

I believe that our chances of preventing a single CO death are small mainly because of the low risk.  Of course, there are many unconsidered factors that could greatly increase or decrease this estimate. Feel free submit your own risk estimate as a comment to this blog post.

In my next post I’ll propose a simpler combustion safety evaluation-and-mitigation protocol. Then, we can work together on perfecting the protocol if you like.

Questions: Does anyone know of a documented case of a CO death, or a customer treated for CO poisoning  in a hyperbaric chamber, that is related to residential energy retrofit? Does anyone know of a documented case of a  lawsuit over a CO death or serious illness relating to residential energy retrofit?


8 thoughts on “Combustion Safety Testing and Risk Elimination”

  1. 1) as we tighten homes and install good vent fans the odds of hurting our clients will go up.

    2) Would it cost less to have mandated sealed combustion appliances years ago and some day we would not have to test for WC? Then all the years of testing every time the homes changes, simplified test or complicated.

    3) I agree with the comment of a good CO alarm and not what is being mandated. Lets make WC so complicated no one can do it right so the laws will change to require sealed combustion. True sealed and not like the unit I saw today. I could put all my fingers through the hole around the P Trap. I’m hoping the install was not complete at the time of my visit.

  2. If we wanted to eliminate all risk none of us would fly. We can eliminate all the risk. We can mitigate the risk by folloing the prescribed Codes that the AHJs are required to inspect too. NFPA 54 and 31 handle the issues of venting for furnaces and boilers anf the LBL report seems to indicate that following 54 and 31 will reduce the risk to the lowest possible level. But nothing will reduce risk to zero. The codes that have been accredited by a third party as having been developed correctly with proper industry (for furnaces adn boilers industry input is from the HVAC contractors and technicians)should be the final determining factor. If done correctly the risk is reduced and the furnace and boliers will operate at ther correct efficiency IF properly setup.

    1. Pat,

      Thanks for your comment. The LBL report echos your comments about following the venting codes. The appliances aren’t perfect but excessive testing is unlikely to be cost-effective in finding real important problems.

  3. John,

    Your point on relative risk is well taken, but shouldn’t we also consider the health effects from low level carbon monoxide poisoning, fires from flame roll out, etc., which are real and potential hazards that can be prevented by performing proper testing. CO and worst case testing are relatively simple and quick tests which protect the occupants, the structure and also protect agencies and contractors from potential liability.
    (Does Bob realy have difficulty remembering and understanding the testing procedure?)

    1. There are so many potential risks that are at least as important as CO that we could spend all of our conservation funds trying to eliminate them. For example, radon, formaldehyde, asbestos, and cockroaches. What is our goal? I favor combining the benefits of energy efficiency and health but where do we draw the line with health?

  4. In my 26 years of experience in the WAP, I have never seen or heard of a death caused by CO poisoning that was related to Weatherization. This includes experience pre-CO testing, pre-worst case testing and testing with pump monoxors. I have found and corrected many combustion appliance related CO problems, including the rare ambient CO issue. I cannot say that these corrections were permanent, things change. I have also seen a lot of resources wasted on non-issues, like correcting low levels of CO in a perfectly good combustion vent on a new furnace with an induction fan. It seems to me that ambient CO could be easily discovered with a decent CO detector. Some CO detectors (and personal CO monitors) and smoke alarms do not work, so let us find and install detection equipment that does work.

  5. John, We in CT had a recent situation if not for the timely weatherization work on a small multi-family dwelling, I am sure we would have been reading about a mother and her 5 children living in an apartment just above a faulty combustion appliance in the basement (sleeping at the time) were found dead due to CO poisoning. When we entered the space our CO monitors went off indicating 200 ppm CO concentration in that space.
    As for the actuarial probability of how many people will die due to CO poising, and whether our efforts can or cannot really effect that risk, I guess some would state that IS acceptable, as long as it is not their wife, daughter, mother, father or another family member; however, I think this effort is worthy of the cost, per the real example above – who’s family did we save and how many future families did we really save – let’s run the actuarial numbers on that.
    How many such incidents really happen that goes unreported, thus uncounted in the actuarial risk assessment?

    1. Bernie,

      Remember that this discussion is about simplifying the process of combustion testing and not eliminating it. Our technicians measure CO and mitigate it, and I certainly wouldn’t change that. What I’m questioning is the worst-case testing procedure, which as Bob Davis points out, is difficult to remember and understand.

      I think that there are many incidents about CO, asbestos, formaldehyde, falls, and poisoning that go unreported. I’m using the stats as a relative indication of risk.

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