Commecial Dryers used for locker room exhaust?

[klarenbeek]

I have a design professional who proposed the following locker room exhaust system:

New locker rooms at a local college football stadium. Locker areas require 1310 cfm of exhaust. There is a laundry room with 2 commercial dryers somewhat open to the locker space--walls do not go up to structure and there is also a pass-through opening in the wall between the locker area and the laundry. Each dryer exhausts 750 cfm when running. He wants to put a variable frequency drive on the locker room exhaust fan interlocked with the dryers. When one dryer is running, the locker room fan would ramp down to 560 cfm, if both are running, the exhaust fan would shut off and all exhaust for the locker room space would be through the dryers.

I'm assuming he wants to do this to cut back on makeup air requirements.

Any thoughts on if this would be acceptable under the 2009 IMC?

 

[cda]

maintance over the years?

seems like it would cost more for the electronics to be added

what if they change out the dryers??

 

[Gregg Harris]

I have a design professional who proposed the following locker room exhaust system:New locker rooms at a local college football stadium. Locker areas require 1310 cfm of exhaust. There is a laundry room with 2 commercial dryers somewhat open to the locker space--walls do not go up to structure and there is also a pass-through opening in the wall between the locker area and the laundry. Each dryer exhausts 750 cfm when running. He wants to put a variable frequency drive on the locker room exhaust fan interlocked with the dryers. When one dryer is running, the locker room fan would ramp down to 560 cfm, if both are running, the exhaust fan would shut off and all exhaust for the locker room space would be through the dryers.

I'm assuming he wants to do this to cut back on makeup air requirements.

Any thoughts on if this would be acceptable under the 2009 IMC?

Where will the makeup air for the dryers come from? IMC 504.5

 

[north star]

+ +

In conjunction with Gregg Harris, ...when the exhaust fans "ramp down"

or shut off altogether, will the HVAC units then "ramp up" to provide

make up air for the dryers?

+ +

 

[klarenbeek]

There will be a makeup air unit bringing in about 2500 cfm to account for both locker room exhaust and shower/toilet exhaust. Because the DP intends to use dryer exhaust as part of the locker room exhaust whenever the dryers are running, makeup air for the dryers will be provided through the makeup air unit. The total exhausted air will remain constant, he just wants to change what is used to exhaust the space air. By doing this, he can use a smaller makup air unit, 2500 cfm vs. 4000 cfm if the dryer exhaust is not also used for space exhaust required by table 403.

As far as cost, that's between the DP and customer. Also, we only do inspections at time of initial installation or appliance replacement, not maintenance inspections throughout the life of the building.

I guess my primary question is, can air exhausted by dryers also be used as exhaust air required by table 403?

 

[brudgers]

I have a design professional who proposed the following locker room exhaust system: New locker rooms at a local college football stadium. Locker areas require 1310 cfm of exhaust. There is a laundry room with 2 commercial dryers somewhat open to the locker space--walls do not go up to structure and there is also a pass-through opening in the wall between the locker area and the laundry. Each dryer exhausts 750 cfm when running. He wants to put a variable frequency drive on the locker room exhaust fan interlocked with the dryers. When one dryer is running, the locker room fan would ramp down to 560 cfm, if both are running, the exhaust fan would shut off and all exhaust for the locker room space would be through the dryers. I'm assuming he wants to do this to cut back on makeup air requirements. Any thoughts on if this would be acceptable under the 2009 IMC?

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.

 

[gbhammer]

The MEP Engineer not Architect is trying to pull a fast one.

A locker room laundry as an F-1, really, you,ve been at hooka bar a bit to much or the leap years are catching up with you.

 

[brudgers]

OP: "Dryer exhaust systems shall be independent of all other systems..."

F1: I've seen it proposed for a pizzeria because pizzas (with a capital "P") are baked...right here, in River City.

 

[globe trekker]

comments deleted by globe trekker

 

[Papio Bldg Dept]

The MEP Engineer not Architect is trying to pull a fast one.A locker room laundry as an F-1, really, you,ve been at hooka bar a bit to much or the leap years are catching up with you.

This reminds me of the 'grocery store bakery' thread being an F-1.

back to the OP: I am working from the 2006 IMC, but did you request/see the engineer's calculations for common ventilation systems as required by 403.3.2? Otherwise, I don't see anything in the IMC that would prohibit the system they are proposing.

 

[brudgers]

This reminds me of the 'grocery store bakery' thread being an F-1. back to the OP: I am working from the 2006 IMC, but did you request/see the engineer's calculations for common ventilation systems as required by 403.3.2? Otherwise, I don't see anything in the IMC that would prohibit the system they are proposing.

The exhaust system is not independent of the locker room exhaust system in the proposed scenario.

 

[Papio Bldg Dept]

The exhaust system is not independent of the locker room exhaust system in the proposed scenario.

My mistake. I thought the OP poster noted that they could operate independently, and that the locker room exhaust would only be diminished when the clothes dryer was operational.

 

[globe trekker]

Gas or electric dryers (RE: Section 303.3 in the 2006 IMC)?

.

 

[brudgers]

My mistake. I thought the OP poster noted that they could operate independently, and that the locker room exhaust would only be diminished when the clothes dryer was operational.

When the showers and toilets are exhausted through the clothes dryer exhaust, it is difficult for me to see the clothes dryer exhaust as being independent. The possible issues arising from the use of hot humid air from the showers and noxious fumes from the toilets as supply air for the dryer is left as an exercise for the reader.

 

[mtlogcabin]

2009 IMC

504.1 Installation.

Clothes dryers shall be exhausted in accordance with the manufacturer's instructions. Dryer exhaust systems shall be independent of all other systems and shall convey the moisture and any products of combustion to the outside of the building.

 

[klarenbeek]

I should clarify-there is a separate fan for the toilet/showers that is stand alone and not in the equation (other than makeup air requirements). Then there is a separate fan for general exhaust for the locker room. This is the one he wants to interlock with the dryers and slow down/turn off when the dryer/s are running. The dryers will be ducted out separately from the locker room exhaust fan in accordance with manufacturers instructions.

I know the commentary is not code, but the intent of the independent of all other systems is due to the moisture and lint that is in the dryer exhaust, to keep them from building up in the exhaust duct. That intent is met in this design. The DP is wanting to use the dryer exhaust for a secondary purpose. This is no different than in a commercial kitchen. A 20x20 kitchen requires 280 cfm of exhaust per table 403 based on net floor area. If a type I hood is in the kitchen exhausting 1500 cfm, I don't require an additional exhaust fan for general exhaust. The hood serves the dual purpose of exhausting the grease laden vapors and general exhaust for the space. Remember, type I exhaust is required to be independent as well. It is an independent system, just used for more than one purpose. This is the way my CBO is leaning.

 

[gbhammer]

2009 IMC504.1 Installation.

Clothes dryers shall be exhausted in accordance with the manufacturer's instructions. Dryer exhaust systems shall be independent of all other systems and shall convey the moisture and any products of combustion to the outside of the building.

Thanks mt. It always makes it easier when some one throws in the code reference.

 

[brudgers]

I should clarify-there is a separate fan for the toilet/showers that is stand alone and not in the equation (other than makeup air requirements). Then there is a separate fan for general exhaust for the locker room. This is the one he wants to interlock with the dryers and slow down/turn off when the dryer/s are running. The dryers will be ducted out separately from the locker room exhaust fan in accordance with manufacturers instructions. I know the commentary is not code, but the intent of the independent of all other systems is due to the moisture and lint that is in the dryer exhaust, to keep them from building up in the exhaust duct. That intent is met in this design. The DP is wanting to use the dryer exhaust for a secondary purpose. This is no different than in a commercial kitchen. A 20x20 kitchen requires 280 cfm of exhaust per table 403 based on net floor area. If a type I hood is in the kitchen exhausting 1500 cfm, I don't require an additional exhaust fan for general exhaust. The hood serves the dual purpose of exhausting the grease laden vapors and general exhaust for the space. Remember, type I exhaust is required to be independent as well. It is an independent system, just used for more than one purpose. This is the way my CBO is leaning.

A locker room with 100 sweating football players, plus coaches is going to generate a significant amount of warm humid air which then must be exhausted through the dryer in addition to the warm humid air from the dryer. A piece of equipment that is most likely not designed with that sort of intake air in mind.

IMO, the kitchen exhaust hood is somewhat different because it is not dependent upon differences in temperature and humidity in order to operate properly in the way a clothes dryer is.

Just out of curiosity, the mechanical calcs do show that level of occupant load, don't they?

 

[mtlogcabin]

I should clarify-there is a separate fan for the toilet/showers that is stand alone and not in the equation (other than makeup air requirements). Then there is a separate fan for general exhaust for the locker room.

This is the one he wants to interlock with the dryers and slow down/turn off when the dryer/s are running.

The dryers will be ducted out separately from the locker room exhaust fan in accordance with manufacturers instructions.

Unless the room has an occupancy sensor to overide the dryers how do you assure there is proper ventilation for the 100 sweating football players that "may" be in the locker room when someone turns on a dryer?

I would hang my hat on the code section and tell him no. Dryers shall be seperate exhuast

 

[north star]

& &

"I would hang my hat on the code section and tell him no........Dryers shall be seperate exhuast."

FWIW, I agree!......Cite the applicable code section to your BO and let theonus be on him/her......That way, at least you will be [ code ] accurate,

without citing the Commentary.

& &

 

[Papio Bldg Dept]

I am confused, dryers can not handle warm humid air, or just the warm humid air of sweaty people? How do these dryers function adjacent to washers? I am confused. Are we saying that an independent/separate exhaust is required for the clothes washer area too?

 

[Frank]

The required air volume is being exhaused from the space.

The required outside ventilation air is being provided.

IF he does not reduce the exhaust fan or increase supply air when the dryers are running then there will be a negative pressure pulled on the building reducing the efficiency of the dryers toilet exhuast etc.

I don't see any problem with controlling the exhuast system this way.

The supply air for the dryers is being drawn from thelocker room either way.

 

[mtlogcabin]

I am confused, dryers can not handle warm humid air, or just the warm humid air of sweaty people? How do these dryers function adjacent to washers? I am confused. Are we saying that an independent/separate exhaust is required for the clothes washer area too?

A dryer is designed to handle the warm humid air that it produces. When you use additional warm humid air through the make air to the dryer it will take longer to dry the clothes and reduce the efficiency of the unit.

If he is trying to save energy he would have to prove it and I don't think he could very easily.

 

[brudgers]

I am confused, dryers can not handle warm humid air, or just the warm humid air of sweaty people? How do these dryers function adjacent to washers? I am confused. Are we saying that an independent/separate exhaust is required for the clothes washer area too?

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.