This weeks case

RayWohlfarth

I am not saying the name of this case because it would give away the cause of the accident. A university contact asked me to meet him at a building we didnt service. It was during a bitter cold snap with temps in single digits. When I arrived, the boiler room was filled with people with clip boards and cameras.(This was before cell phones)

When asked what was going on, the contact said the building was evacuated several days before due to people complaining of headaches, dizziness, and nausea. The measured carbon monoxide levels were high. The boiler room had 2 atmospheric boilers and 2 atmospheric water heaters. The boiler room had a mechanical air handling unit for combustion air.

The building had a parking garage next to it and attached. Each level of the underground parking garage had an entrance to the building. Due to the cold weather, the parking lot attendees closed the rollup doors to the parking to avoid freezing pipes. The parking garage had a large exhaust van to remove the vehicle exhaust.

As usual, I will let you know the cause of this accident on Friday when the video airs. What do you think happened?

Ray

ratio

Since the roll up doors were closed, the parking lot exhaust fans were depressurising the attached building & backdrafting the flues.

mattmia2

I'm going to go with they built the parking structure around the air intake for the boiler room and some vehicle was idling near it or the line of cars waiting to enter/exit were near it.

JUGHNE

In addition to that, the boiler room door may have been left open.

Some have a "screen" door with security bars for added ventilation.

gerry gill

I'm going with what 'ratio' said.

EBEBRATT-Ed

Air handler for make-up air to the boiler room was sucking in exhaust fumes from the cars and depositing it in the boiler room.

CLamb

Why does a parking garage have water pipes?

mattmia2

Fire sprinklers, drains, possibly other things.

ChrisJ

mattmia2 said:

Fire sprinklers, drains, possibly other things.

Probably moot, but there are dry sprinkler systems.

I don't know the requirements of where, and when they can be used etc but I do know they exist. I'm sitting by one right now.

JUGHNE

Dry sprinkler systems are used in unheated areas, mostly attics.

They have to be pretty air tight as they are pressurized with a certain amount of air.
A compressor will maintain that pressure within it's capacity.

If the air pressure drops to a certain point then the fire alarm will sound a trouble signal. Often ignored, the pressure drops enough to trip the water valve open, the pipe fills with water.
I suppose the water will flow depends upon the size of the air leak.

Once the water valve trips the fire alarm is set off.
The FA and water trip valve are then reset.
The dry system is drained and the air pressure re-established.
If the air holds then perhaps all is well for a while.
Or you get to crawl in a terrible attic above the insulation and listen or do bubbles for air leaks.

If not corrected and the water left in the pipe then when freezing temps come, then things can go bad quickly.

But you can find the leaks by looking at the ceiling.

Another system I have seen is the glycol loop.
We have one at a nursing home, above the carport used for ambulances.

No air, glycol is somehow held where the outdoor heads are located.
If a head opens then the system water follows.

As the world had to get "safer", this same home had to have heads outside in the egress areas and also in the walk in freezer and cooler.
These heads are special that have a glycol loaded portion that sticks in the freezing area.

This in not my trade, just 40 years of observation and repairing parts of other systems the the sprinkler pipe fitter ruined as he made modifications.
(After all he was always the most important guy on the job.....just talk to him for awhile....BTW, the only union worker also.)

RayWohlfarth

@ratio You got it right first. In addition to the garage doors closing, the makeup air fan for combustion was tripped on the freezestat The installer didnt connect it according to the design. The International Fuel Gas Code requires an interlock that prevents the boilers and water from running without proving the fan was running. So here is the link for the video, The case of the failed makeup air unit
https://www.youtube.com/watch?v=bmiVMv568tA

@CLamb Not sure why they had water pipes in the garage. Like I said, it was my first time there. I never thought to ask.

The second video is an article I wrote for Engineered Systems Magazine entitled, Replacing a steam boiler. It goes into some items to check when replacing the steam boiler.
https://www.youtube.com/watch?v=4sMCtC-RyL4

Thanks everyone and have a great weekend
Ray

PC7060

Thanks for sharing. 

Typical knee jerk reaction.  Replace everything instead of fixing the problem. Hopefully you got the work for the new installation.  

RayWohlfarth

@PC7060 No They chose the same boiler because it would make the changeout easier. Thanks for watching and the comment

MichaelSchwarz

Thanks for the video.