Karen, George is spot on the 13 vs 13R . Percentage has nothing to do with it. It has to do with useage. If the commercial spaces are going to be open to the public (not considered "incidental"), then it should be a 13 system. Check with you building codes.
Both a 13R and a 13 require an FDC, so each would require a backflow preventer (subject ot local codes) At 10:29 AM 8/12/2009, you wrote: >As for the building it is an apartment building with three floors of >apartments. The ground level has apartments and the front of the building >has space for 6 commercial locations. I don't know what will go in those >spaces. Since the majority of the building is apartments I designed as a >13R. > >The second question is in reference to 13R 6.7.1.6 "A listed backflow >prevention assembly shall be considered a check valve, and an additional >check valve shall not be required". In all my commercial builds I use a >double check backflow. So I guess my confusion is because there is mixed >occupancy would I use the double check because there IS commercial or just >use a single check BECAUSE its 13R. > >Karen Purvis >Senior Designer >Facility Systems Consultants >713 South Central Street, >Suite 101 >Knoxville, TN 37902 >ph.865-246-0164 >fax 865-246-1084 >-----Original Message----- >From: [email protected] >[mailto:[email protected]] On Behalf Of George Church >Sent: Wednesday, August 12, 2009 10:23 AM >To: [email protected] >Subject: RE: Mixed occupancy > >Hmm. If the business portion of the occupancy is incidental to the >residential use of the building, as in a cafeteria serving a dorm, then you >drag over the couple items of #13 that 13R references for areas outside the >dwelling units. If it's a restaurant serving the general public but located >in a hotel, then the design is to #13 for the entire building- unless its >two buildings within the definitions of building separation in your >applicable building code. In either case, the riser is sized by the >hydraulic demand. > >I cannot imagine where you'd have a situation where the backflow preventor >is dependent upon 13 or 13R. In 13D you could omit the BFP in certain >instances, but that doesn't seem to be in your question. Why would the >occupancy change the need for backflow prevention in your mind? Water still >sitting there stagnant. > >glc > >-----Original Message----- >From: [email protected] >[mailto:[email protected]] On Behalf Of Karen Purvis >Sent: Wednesday, August 12, 2009 10:06 AM >To: [email protected] >Subject: Mixed occupancy > >These probably are questions everyone knows the answers to but I can't find >the answers: > > > >1. If you have a mixed occupancy (residential & Business) and your >design is a 13R does your riser need to be at least a certain size or just >large enough to serve the hydraulic area? >2. Because there is something other than residential in the building >would I not need a backflow on the riser? > > > >Karen Purvis > >Senior Designer > >Facility Systems Consultants > >713 South Central Street, > >Suite 101 > >Knoxville, TN 37902 > >ph.865-246-0164 > >fax 865-246-1084 > > > >_______________________________________________ >Sprinklerforum mailing list >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email to:[email protected] >(Put the word unsubscribe in the subject field) > >_______________________________________________ >Sprinklerforum mailing list >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email to:[email protected] >(Put the word unsubscribe in the subject field) > >_______________________________________________ >Sprinklerforum mailing list >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email to:[email protected] >(Put the word unsubscribe in the subject field) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
