Okay I haven't jumped into the info of fresh air through ashrae or the epa just yet but I wanted to hear your thoughts on this example. So obviously many businesses are closed as of now because of the virus and I noticed that the property management company for a business park I work at has shut off all the mechanical equipment most likely to pat themselves on the back for saving energy. I am unable to find my Indoor Air Quality solutions book but I just wanted to get your thoughts since staff from security and janitorial still have to walk through these 110k sq ft buildings. I am wondering if the odds of getting sick of anything other than the virus are greater due to no air flow?
Depends on what is off gassing inside the building. If it’s a new building then you may still have adhesives and paints and glues curing. Chemicals in carpets, drywall, etc..., cleaning products, CO2 build up...
Some buildings monitor for that stuff and operate their OA requirements based on the sensor input.
Other buildings go with the ASHRE minimum fresh air numbers for the occupancy and type of building it is.
I didn’t not have a great answer for you but if there are people in the building then it is still occupied and should be treated as such. I would instead suggest they should adjust the amount of OA to suit the new occupancy levels. Janitors are people who have rights to a safe work place and deserve to work in a conditioned place just like the rest of us...
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... As I think about this more I recall the number of times I’ve worked in a freezer and on a sweltering hot roof top. The difference here is that I signed up to work in those temperature and they did not.
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Quickly, I must hurry, for there go my people and I am their leader!
We would use 10% of total capacity as Occupied / Unoccupied
If the base personnel Security, janitorial, electricians, engineering is below that # does it really matter? Look at it this way 110K Sq Ft with a hand full of personnel there probably plenty of air leaks, fans that are operating should be at there 10% minimum anyway.
That's a good question ( what is considered occupied and what isn't ) worth looking up in the International Mechanical Code.
Your right, I should be more careful about how in express that. I was not stating a known fact, that was a personal opinion, I haven’t confirmed that and it would need to be checked for accuracy before they approach the customer with that information.
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Quickly, I must hurry, for there go my people and I am their leader!
This is only a guess and a remembrance by memory, buy I thought the fresh air requirement used to be 15% and it was change up to 20% by code?
Then the amount of people exhaling a given amount of CO2 entered into the figuring, I think.
www.Contracting Business. June 1,2006 an article by Rob 'Doc' Falke, titled "How Much Fresh Air Is Enough?" In his given condition and formula the #'s say 20%
20% is a lot when you're trying to cool a place,as now desired sometimes 70, when it's 100 out with 58% humidity.
I was referring to the OP of shutting down all equipment for a building. with no air movement, or mechanical cooling, I would say there is a possibility for high humidity causing problems.
I think raising the set points would be a better option, rather than killing everything.
I'm sure there are a lot of "energy management" companies creaming their panties right now with the MASSIVE amount of money they are "saving" their customers.
In my experience it’s depended on what the blue prints say or the local mechanical inspector. If it had a kitchen in it there always was a MUA unit.
Residential installation was 3-4” with a damper, Commercial Splits and HP was 4” to 18” with a manual damper at the return section for “recommended specs” you needed to basically (at a minimum)match the exhaust “bathroom” fans.
In the photo document that's shown lower right corner, you can see it...section 402.2 its very short..
Tks. I did not have my screen on "full screen" so the print was real small. lol.
But, I think that says 4% of floor space. I'm not sure how that converts over to % of indoor air,as in CuFt %.
It did not mention how old the building was also...air leakage alone in it should be considered a factor..I have also seen concrete floors wick water through into the buildings mainly at the floor seams. a moisture meter confirmed it.. Separate dehumidifiers was installed with the condensate tubing being drilled through the exterior walls and sealed as they was the worst rooms. It was pointed out the building also had a lower base elevation than the rest..I joked about ripping out the parking lot around the building to re-pitch the water away from it..I also got into trouble for joking about it, lol..Some people just don't understand. lol
I do use a Flir E4 to show air leakage...It one of the best tools in my arsenal...especially ductwork leaks...and checking vent temps. I also found a few flex connections that blew off in the dropped ceiling that way...the customer was really happy especially because no one else checked it..
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Originally Posted by VTP99
