Commecial Dryers used for locker room exhaust?

[Frank]

Dryers handle wet fabric by evaporation. If the air is already saturated with moisture, the dryer cannot do its job effectively. It is reasonably likely that the ambient air would be outside the operating specifications of the dryer - but if the manufacturer has a UL listing which would allow such a use and the manufacturer's literature indicates that each dryer is suitable for exhausting 1500 square feet of locker room in addition to drying fabric, I'll buy in to the design.

I doubt it. A commercial laundry plant that is not air conditioned is a lot warmer and more humid than a locker room. Wander through a hotel laundry when they are operating.

A 750 cfm 120 pound capacity dryer has a gas input of 270 000 BTU/hr or 870 btu per pound of air 95 F 80 % rh inlet, the difference between 90 F and 40% humidity and 95 F and 80% humidity inlet air (approx 7 BTU per pound) won't be noticed.

http://www.cissell.com/adv_pdf/al11-0388.pdf

 

[brudgers]

The small one is 1600 cfm, not 750.

I don't see a listing for it's use as an HVAC exhaust fan.

And commercial laundries do not typically entail the life safety considerations of assembly occupancies.

 

[Frank]

The small one is 1600 cfm, not 750. I don't see a listing for it's use as an HVAC exhaust fan.

And commercial laundries do not typically entail the life safety considerations of assembly occupancies.

OOps I read the metric 755 l/sec but the principle is the same that the input air entalpy is little different relative to the heating element. ratio of 7 btu / lb vs heat input of around 400.

2009 IMC

501.2.1 includes clothes dryer exhuast in the types of exhaust systems.

403.1 mandates that exhaust and supply air be about equal and 504.5 requires makeup air for dryers over 200 cfm.

Exhaust air is air removed from the space through adjacent shower room fans, kitchen hood fan, dryer exhaust, or fume hood exhaust--they are all air exhausted.

Note that in Table 403.3 locker room exhaust is required for Educational occupancy classification but the code is silent on sports and amusement locker rooms. College sports complex would not fall under Educational as that is limited to through 12th grade. Can probably get to a requirement under public spaces toilet and shower rooms.

 

[gbhammer]

Frank has a real good argument, I would like to see the DP's calcs to see if he and frank are on the same page.

 

[brudgers]

OOps I read the metric 755 l/sec but the principle is the same that the input air entalpy is little different relative to the heating element. ratio of 7 btu / lb vs heat input of around 400. 2009 IMC 501.2.1 includes clothes dryer exhuast in the types of exhaust systems. 403.1 mandates that exhaust and supply air be about equal and 504.5 requires makeup air for dryers over 200 cfm. Exhaust air is air removed from the space through adjacent shower room fans, kitchen hood fan, dryer exhaust, or fume hood exhaust--they are all air exhausted. Note that in Table 403.3 locker room exhaust is required for Educational occupancy classification but the code is silent on sports and amusement locker rooms. College sports complex would not fall under Educational as that is limited to through 12th grade. Can probably get to a requirement under public spaces toilet and shower rooms.

2006 IMC has locker rooms under public spaces. But I don't buy the 0.5 cfm/sft.

That's providing less than 1/5 the fresh air for 100 football players than is required for 100 sedentary spectators.

 

[north star]

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Some might want to assign the Locker Room as a Type "U"

Occupancy Group, ..." stables " ! [ insert the sounds of a

bunch of horses whinnying here ]

=

 

[Frank]

2006 IMC has locker rooms under public spaces. But I don't buy the 0.5 cfm/sft.

That's providing less than 1/5 the fresh air for 100 football players than is required for 100 sedentary spectators.

Wonder why it was removed for 09 and 12 with the rework of this table?

The code change proposals that reworked the table only gave as justification to be more like ASHRAE 62.1.

 

[brudgers]

Wonder why it was removed for 09 and 12 with the rework of this table? The code change proposals that reworked the table only gave as justification to be more like ASHRAE 62.1.

100 sweating football players in pads perhaps?

 

[Dr. J]

Regarding the question of how much outside air is required - the OP indicates 2009 IMC. One of the differences with the 09 version is that outside air is not required for a locker/shower/toilet room - only exhaust. Occupant load has nothing to do with it either - it is just a CFM/SF requirement.

Regarding whether or not the dryer will work - the design is specifically addressing the potential of exhaust affecting the dryer, so no problem there. Frank is really close to the psycrometrics of the dryer - the inlet air RELATIVE humidity does not have that much to do with it, particularly since it is already in a conditioned space. The inlet air will be in the 70's regardless of the relative humidity. The difference in ABSOLUTE humidity between 78 deg/40% RH and 78 deg/90% rh is 50 vs 140 grains. Assuming the dryer exhausts air around 120 deg (sounds like a "low" setting to me - the "cotton" setting is probably higher), it is capable of absorbing up to 550 grains. The potential loss in capacity with 90% RH rather than 40 % rh inlet air is only about 15%. It is unlikely a barely-conditioned commercial laundry would have a lower absolute humidity than a conditioned locker room. Besides this is not a code issue.

Regarding separate exhausts - As far as the code is concerned, it is the same situation as a Type 1 kitchen hood or a fume hood exhausting the required room exhaust. So deal with it. Either prohibit both dryers and hoods from acting as general room exhaust or don't, but be consistent. If you prohibit hoods and dryers from acting as general exhaust, at least make that known so businesses can take their tax dollars elsewhere.

Regarding good design - It is a great idea. the challenge of how to deal with a significant piece of equipment that is used sproadically is always a tough one. This is a good solution.

 

[gbhammer]

And Dr. J launches from the free throw line... up...up...wow look at the distance that guy can really fly... slam dunk ladies and gentleman... slam dunk.

 

[brudgers]

Sprinklers or one hour separation still required...which is where I came in.

 

[Papio Bldg Dept]

And Dr. J launches from the free throw line... up...up...wow look at the distance that guy can really fly... slam dunk ladies and gentleman... slam dunk.

If I remember correctly, Dr. J usually drove base-line and came up and under from behind the back board...either way, his dunks were aaaamazing.

Thank you Dr. J for taking to the time to clarify the operational metrics of the OP....cleared up my confusion.

 

[klarenbeek]

We've decided to allow the system the way the DP proposed. Because 2009IMC doesn't address non educational locker rooms, we used section 403.3 which says to use the occupancy closest to the actual occupancy, if it is not listed on the table. The closest to a college locker room would be the locker room under educational facilities. DP had no issue with that. In fact, a nearby private high school will also be using the facility. Our decision was based on the following:

Code states that exhaust is required, it does not address how that exhaust is accomplished. (No different than the kitchen hood scenario) How efficient the dryer is is not in the code either.

The only way the dryer exhaust is connected with the other fans is through the control wiring. Ducting is separate so the intent of independent exhaust system for dryers is met.

The design meets both exhaust and makeup air requirements of section 403. It also allows for a smaller makeup air unit, lowering both initial cost and operational cost over the life of the building. This college had a playoff game a couple years ago during a raging blizzard in december. We've also had track meets postponed or cancelled in april or even early may because of snow (this facility has a track &field setup as well) so this locker room will definitely be used during times the makeup air needs to be heated.

Thanks everyone for your input.

 

[north star]

= =

Is "brudgers" question about sprinklers or separation still on

the Discussion Table, or did that point get resolved?

= =

 

[Papio Bldg Dept]

So the entire locker room is being classified as a laundry room and meets the requirements of 508.2.5? Can you do that in an assembly occupancy? - obviously a football locker room would be over 750 square feet and have an occupant load greater than 50 and be used for meetings before and after games (as well as half time).

That's assuming an assembly occupancy is applied rather than going with F-1 for the laundry, of course.

It seems to me that make-up air is the least of the design professional's problems.

I don't think it was taken off the table, we just went back to the OP.

 

[beach]

I thought it was more about the "100 sweaty football players".........

 

[brudgers]

I thought it was more about the "100 sweaty football players".........

In a sense, yes. Dryers in a space used for assembly.