08-31 Hot water in commercial buildings

Question: 08-31Code Section: 7Date: 19 October 2008OBC 2006 Reference: 7.6.1.1(4).

Question: (In reference to) an issue with the supply of hot potable water in commercial buildings.

An old legion hall in the west end of Windsor was purchased but the University and converted to classrooms. During the construction phase, the plumber on the site shared his reservations with me regarding the hot water generating system that the engineer had designed and had been granted approval for.

It involved two instantaneous heaters, in series. The distance to the new “public” washrooms, the one’s intended for student and general use was rather long, and the basins are served by electric eye faucets controlled with mixing valves. Neither the plumber, nor I, believed the system would deliver correctly, and at final inspection, we were both proven to be correct. The delivery of hot water to the basins takes longer than forever to get to the spout, and it’s next to impossible to set the balance valve correctly.

Now the problem: I had every intention to write an Order under the OBC, to the contractor, to make the appropriate corrections to the system to allow for proper delivery of hot water to the hand basins. (We) could find any code reference that required there to be hot potable to those basins. The scope of where hot water “must” be is very narrow, and flies in the face of logic. (We called the MAH) and was informed that there is no requirement for hot water currently in the code, except for a VERY narrow scope of use.

Interpretation: Any electronic faucet works much, much better on a hot water distribution system that has a system that has a recirc. if your system is more than 30 metres 7.6.1.1. (4) (a)

It would be a little easier to enforce if the building in question was a dwelling unit, see 9.31.4.3. “In a dwelling unit with a water distribution system” where is the section that says that every building “must have a potable water system?” then it goes on to say that hot water must be provided to fixtures in a dwellings 9.31.3.2. and that there is an acceptable range of hot water supply, 9.31.6.1.

In Part 3, some interesting sections dealing with the subject matter starting with 3.7.4.1.(1)…each building situated on property that abuts on a street in which a public or municipal water main is located shall be provided with or have accessible to its occupants a plumbing system including a potable water supply… here it is clear that buildings must be provided with a water system, 3.7.4.16. says that a distribution system that supplies hot water (not requiring it) shall conform to the requirements found in 7.6.5. and a little further in 3.7.6.5.(1) hot and cold water supply shall be provided to,(a) every plumbing appliance and fixture required by Article 3.7.6.4. Sentence 3.7.6.4.(1) and 3.7.6.5.(1) seem to be the only requirements for hot water in commercial, industrial building. If a system has been designed to accommodate hot water distribution, the intent is to have adequate hot water at each fixture outlet.

Interpretation: Approved at AMES 2009