I am studying ‘The Residential Ventilation Handbook’ by Paul Raymer. Mr Raymer has worked with residential ventilation, design, consulting, teaching for over 30 years.
I just reached the Chapter on Garages. I’ve known for several years the potential problems with an attached garage. Two years ago, I did some recommended work in my garage because of these issues. I carefully sealed the wall between the garage and the house, and I installed a mechanical ventilation fan.
Why is the attached garage important to the Indoor Air Quality in your home? OK! What is in your garage? Mostly stuff you don’t want in the house. Like fertilizer, bug spray, weed killer, gas for the lawn mower. Cars, and other vehicles are usually there also.
Mr Raymer includes a table of Carbon Monoxide levels and comments or the potential for harm to people. I knew some of these, and others I did not. Carbon Monoxide is a colorless, odorless gas that is a byproduct of burning fossil fuels, like gasoline, natural gas, or propane. Carbon Monoxide (CO) is measured in parts per million (PPM)
Here are some entries from the table:
1-2 PPM Normal from gas range, traffic etc.
9 PPM Maximum Allowable Level for 8 hour period in any 12 month period. EPA and ASHRAE. Normal after using an unvented gas oven.
15 – 20 PPM Impaired performance in time discrimination and shorted time to angina response
30 PPM UL standard that detectors not sound an alarm unless exposure is continuous for 30 days.
35 PPM Maximum allowable outdoor concentration for any one-hour period within a 12 month period. EPA – ASHRAE
50 PPM Maximum allowable 8 hour work exposure (OSHA)
150 PPM UL Listed detectors must sound full alarm between 10 – 50 minutes of exposure.
500 PPM Car started from cold in garage with door open, and allowed to run for two minutes
800 PPM Dizziness, nausea, and convulsions within 45 minutes.
6400 PPM Death in 10 – 15 minutes
70,000 PPM Typical tailpipe exhaust concentrations after cold start during the first minute the engine runs.
NOTE: After running for 17 minutes, these concentrations finally drop to 2 PPM