ACH for commercial bathrooms

[Bigwood]

Hi,

How many ACH are required for commercial bathrooms and where in the code is it stated? We have two bathrooms - one is 12x17x14 and the other 8x12x8. Also, I need ductless exhaust fans, which I don't know if they are even rated in CFM.

 

[cda]

Which year edition???

 

[Bigwood]

2015

 

[cda]

Not my area but possibly

TABLE 403.3.1.1
MINIMUM VENTILATIONRATES

Chapter 4 Ventilation: Ventilation, Pennsylvania Mechanical Code 2015 | UpCodes

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up.codes

Check your book

 

[BayPointArchitect]

Off the cuff, I know that the 2015 IMC Table 403.3.1.1 specifies an absolute minimum of 50 cfm exhaust rate capacity but then I think that it might need to increase a little based on the total number of plumbing fixtures if you have many toilets and urinals. As an architect providing a simple set of plans for a new ADA restroom, I always specify the following and call it good enough:

Combination exhaust fan and ceiling light
Manufacturer: Broan-NuTone
110 CFM
Sound rating: 3.0 Sone +/-

In most cases, the contractor will ignore that but install something similar.

Does anyone have an opinion about using a ductless exhaust fan for a public toilet room? It may be legit but this is a new concept for me.

 

[e hilton]

Where does a ductless fan exhaust to? The ceiling plenum?

 

[DJMenitoff]

Ductless exhaust fan is a terrible idea.

 

[Yikes]

In what state / jurisdiction is the project located?

 

[ADAguy]

maintenance nightmare

 

[Paul Sweet]

International Mechanical Code Table 403.1.1.

50 CFM per water closet or urinal if the fan runs continuously, 70 CFM per water closet or urinal for intermittent fan operation.

It looks like the 2015 IMC might allow a ductless fan (footnote g & 403.2.1). In the past all air had to be exhausted.