REQUIRED TOILET ACH in AIA GUIDELINES 1

[edtpro]

The AIA/FGI Guidelines Ventilation table lists toilet rooms in hospitals as requiring 10 ACH at negative pressure. Is this for general toilets only? Does it also apply to toilet rooms inside negative pressure isolation rooms? If not, is there no/any ACH requirement for toilets inside negative pressure isolation rooms?

Thanks for any quick guidance you can offer. I am having a discussion with a colleague and his client and we are interpreting the Guidelines differently.

 

[urgross]

General bathrooms are 10 ACH.

For AII rooms with toilets, refer to ASHRAE 170-2008, addendum f.

 

[edtpro]

Thank you for your answer urgross. However, I don't think ASHRAE 170-2008, addendum f really addresses the issue I was referring to. In reading the document, I don't see anything mentioned within the document about air changes for toilet rooms. Most of the document seems to be spent clearing up misunderstandings about pressure relationships to adjacent areas.

If I may ask another questions as well; does the AIA/FGI state somewhere that the table line item for toilet rooms is only referring to general toilet rooms? I couldn't find that distinction.

Thank you for any further clarification you are able to provide.

 

[tys90]

This one just requires some common sense. Why are toilets exhausted? Should they be exhausted if the space next to it is negative? Where do you want odors and moisture to go?

Plus ASHRAE 170-2008 7.2.1 says all air from AII rooms, associated anterooms, and associated toilet rooms shall be discharged directly to the outdoors. From this, we can conclude that the anterooms and toilet rooms require local exhaust in each room.

 

[edtpro]

Thank you for your reply tys90. And, I agree with your premise concerning negative pressure and local exhaust. The question I was seeking to be answered, however, is whether or not toilet rooms in AII rooms require 10 ACH. The argument opposing mine in respect to my colleague and his client is that the requirement for 10 ACH only applies to general toilets and NOT AII toilet rooms.

To summarize, do AII toilet rooms have a requirement for a certain number of ACH or do they not. I say they do, because I have not seen anything in the standards or codes that differentiates AII Toilet Rooms from General Toilet Rooms in respect to EITHER ACH or pressure to an adjacent area.

Thank you to anyone who has or can contribute to this discussion.

 

[KLH]

The AIA ventilation table only has one listing for "toilet rooms" in patient related areas. So I would assume it applies to all toilet rooms whether it's a general toilet room or an isolation room's toilet room.

We've used 10 AC/HR here in PA with no objections whatsoever from the Department of Health.

You stated your colleague or his client had a different interpretation. I curious as to what that interpretation was and what it was based on.

Regards.

 

[edtpro]

Thank you for your reply KLH.

Our company assists hospitals in verifying proper ventilation and pressure relationships for a variety of areas, one being AII rooms. On a recent visit, my colleague had reported to the engineering dept that a couple of the AII rooms were not meeting the 10 ach requirement for the toilet rooms. The engineering dept took issue with this and apparently an architect they use gave them that information. They stated that 10 ACH weren't required for AII toilet rooms. That is what started the discussion. I haven't been presented with any information to support their assertion. I have contacted FGI and ASHRAE for an interpretation, but have not heard back.

My own viewpoint is that if there was an exception for toilet rooms in AII rooms in respect to ACH, it would have been mentioned in the addendum that urgross pointed out above or in the various guidelines and/or codes. I can't find those exceptions. Therefore, I don't know why I would treat AII toilet rooms any differently.

 

[DRWeig]

The most successful solution for me has been this:

If the wording in the code can possibly be interpreted in more than one way, don't debate. Ask. There's an authority having jurisdiction who will be approving or rejecting the decision. The ones I have dealt with were happy to resolve issues before they were found on drawings or in the field.

Call them up!

Best to you,

Goober Dave

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[edtpro]

Thank you DRWeig for your reply. As I indicated above, I have contacted groups like AIA/FGI and ASHRAE. I have even contacted the AHJ (in this case, the state of Georgia) to see what their interpretation is on the issue. However, as you may be aware, AHJs can take their time in getting back to you. I have turned to this forum to simply hear the advice of colleagues on the specific issue.

 

[DRWeig]

I'm also a Georgia guy. I understand.

Best of luck resolving it!

Best to you,

Goober Dave

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[317069]

Toilet should be negative to surrounding area no mater what this area is.
isolation room is negative to other part of the hospital, toilet room in isolation area should be negative to surounding area which is the isolation room i this case,
also I belife Georgia code like other codes request to provide exhaust fan in each washroom, that men you have to exhaust. but about the number of ACH if nobody defined it officialy then use engineering practis beside referances such as ASHRAE or other as the codes say usual

 

[urgross]

The bathroom is a part of the isolation room. The AII room is for 12 ACH. What you seem to be saying is that you want to have an AII room sucking air from the bathroom to save 2 ACH? Do you also put a pressure independent air control valve to make sure you are saving 2 ACH on a bathroom?

 

[edtpro]

Thank you for all the replies. Our original position was that AII Toilet Rooms are required to maintain negative pressure supported by at least 10 ACH computed on exhausted air. This position seems to be confirmed by an unofficial email I received on Friday from the ASHRAE 170 Chairman. The text of the email with my follow-up questions is below. Please feel free to continue this discussion. I value your input. (You might notice that my now italicized question was misunderstood to refer to the Main Room instead of the Toilet Room. I simply did not word the question well.)

ORIGINAL QUESTION BY WAY OF FGI WEBSITE FORM
The AIA ventilation table lists toilets as requiring 10 ACH at negative pressure. Is this for general toilets only? Does it also apply to toilets inside negative pressure isolation rooms? If not, is there no/any ACH requirement for toilets inside negative pressure isolation rooms?

If there is a requirement for ACH (10 or otherwise) inside negative pressure isolation rooms, is the ACH computed by the amount of exhaust in the toilet room? Does that change depending on whether there is a supply included inside the toilet?

Thanks for any quick guidance you can offer. I am having a discussion with a colleague and his client and we are interpreting the Guidelines differently.

ANSWER FROM FGI
Mr. Silverman:
I have forwarded your request to the chairman of ASHRAE 170 for response. I would anticipate a response from him shortly.

I have also included addenda "f" which addresses toilet and anterooms that are a part of the airborne infection isolation room. When it states directly opens onto an AIIR it does not mean without a door. It means without opening onto any other spaces.


Douglas S. Erickson, FASHE, CHFM, HFDP
Chair
Health Guidelines Revision Committee

ANSWER FROM ASHRAE 170 CHAIRMAN
I offer the following unofficial interpretation of Standard 170.

Questions are:
Q1. The AIA ventilation table lists toilets as requiring 10 ACH at negative pressure. Is this for general toilets only?
Response 1.
[li]No – this is not for general toilets only. The Table value for toilets apply to the toilet associated with the AII room.[/li]
Q2. Does it also apply to toilets inside negative pressure isolation rooms?
Response 2.
[li]The Table value for toilets apply to the toilet associated with the AII room.[/li]
Q3. If there is a requirement for ACH (10 or otherwise) inside negative pressure isolation rooms, is the ACH computed by the amount of exhaust in the toilet room?
Response 3.
[li]The Total ACH for the AII room is 12 ACH.[/li]
[li]Normally, the ACH for the AII room is calculated based on the air exhausting via the exhaust grille in the AII room.[/li]
[li]However, some of the 12 ACH could be provided by exhausting from the toilet and transferring air from the AII room.[/li]
Please note: the 10 ACH for the toilet will not be the same volume of air as 10 ACH in the AII room unless the toilet is the same size as the AII room.

My FOLLOW-UP
Thank you very much for your assistance. I have some follow up questions.

Q1. How does one get an official interpretation of a standard?

Q2. I understand exhaust from the Toilet Room inside an AII room can be used to achieve the required total of 12 ACH for the Main Room. Is my understanding correct? If so,

In the case of an AII room with a Toilet Room, should the total ACH for the Main Room be computed by combining the exhaust for both the Main Room and Toilet Room and dividing it by the volume of the Main Room and the volume of the Toilet Room?
ACH = 60(MRcfm + TRcfm) / MRvol + TRvol

Or, should the total ACH for the Main Room be computed by combining the exhaust for both the Main Room and Toilet Room and dividing it by the volume of the Main Room only?
ACH = 60(MRcfm + TRcfm) / MRvol

Or, is there yet another way it should be computed?

 

[DRWeig]

Thank you for posting the ASHRAE response. It's always great when we hear how a problem resolves.

Best to you,

Goober Dave

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[urgross]

Are the AII rooms in question grandfathered?

 

[edtpro]

urgross -

Grandfathering is not a straight forward issue and in respect to life safety should be avoided in my opinion. I know, for instance, that the NFPA does not consider grandfathering a legitimate practice when it comes to medical gas systems. I can't definitively speak to how they or others would view it on additional matters though.

In respect to my original question, however, the rooms are not grandfathered and I'm not sure if that is even possible. Going back as far as the 1987 Guidelines, Toilet Rooms (and "Bathrooms") required 10 ACH.

The whole question centers around whether or not the AIA/FGI Guideline's line item for "Toilet Room" refers to ONLY general Toilet Rooms like those found in corridors and departments or to ALL Toilet Rooms including ones found in AII Rooms.

My position has been that it refers to ALL Toilet Rooms, not just GENERAL Toilet Rooms.

 

[urgross]

I agree on grandfathering, but I'm not the customer. A customer has previouly asked me for an estimate to bring the rooms to compliance. The rooms operate as designed in the 1970's for the standard at the time, 6 ACH. When I informed the customer of the extent of work required and cost, pretty much complete gutting, I think they defecated a lizard. Asked them to call back when they have money. I think they are trying to take care of their grandfathered NFPA 92 smoke control system first, as it impacts the entire hospital.

 

[edtpro]

Yeah, ultimately it's up to the AHJ and/or their corporate safety policies. Of course, if they get hit with a lawsuit and try to hide behind grandfathering as opposed to coming up to best practices, they'll change their tune pretty quickly.

 

[cry22]

Such a bathroom would be 36SF (6'x6') with a 9' ceiling? - needs 60 CFM at 10 ACH. IMC requires 50 CFM if continuous exhaust. Not much of a difference, I'd use the higher number.
Thank you for posting the response.