Health HazardsAre you aware of any plumbing/ health codes prohibiting the use of air chamber systems? I have a PDI report on water hammer arrestors, which clearly establishes that such sytems are useless, but it makes no mention of any health risks. You cannot flush air chamber systems during standard chlorination - got any ideas?
Julius replies: As for the health effects with air chambers, it has been well established that the copper air chambers will have water with an excessive concentration of copper. However, no one drinks the water out of an air chamber. While the water can enter the drinking water, it is so diluted that the concentration of copper is well within acceptable limits. High concentrations of copper result in stomachaches for those who ingest the water.
Some manufacturers of water hammer arrestors are promoting the fact that air chambers may be a health hazard. However, I believe that such a scare tactic is inappropriate. These manufacturers are better off promoting the fact that air chambers do not work. In studies that I have conducted, an air chamber can lose its effective charge (air column) within the first four uses of a fixture.
Realize that with most water conserving fixtures, water hammer protection is no longer a necessity. Hence, people start to think that air chambers work, which they do not.
Condensate Drain QueryI have a question for you regarding condensate drain traps and vents. It seems to me that engineers interpret this differently. Some, at least here in California, regardless of what UPC (Section 803, 5-15-rule) and UMC say about it, argue that this is not a code issue, but instead a matter of the manufacturer's recommendation. What is your interpretation of the code?
Do condensate drains require traps and vents, or not? If the answer is yes, is that true for both primary and secondary C.D.'s? What could take place if traps and vents are not installed? What is the effect of acidic condensate on the cooling coil pan if the C.D. does not drain properly? I would appreciate a detailed explanation.
Julius replies: Condensate drains are one of those anomalies. The condensate drain from mechanical equipment is regulated by the mechanical code. Only the discharge of the condensate is regulated by the plumbing code, not the connection of the piping to the mechanical equipment.
The most recent code is the International Mechanical Code (IMC). There was considerable discussion of the condensate disposal requirements. As far as trap requirements, the IMC leaves them in the hands of the manufacturer. If the manufacturer requires a trap, then a trap is required. If the manufacturer does not require a trap, then a trap is not required.
I have found that the majority of residential air handlers do not require a trap, while the majority of commercial air handlers recommend a trap. When asked the reason for the trap, the engineers for the manufacturers respond that the trap allows the drain pan to work properly. Without a trap, the pressure within the drain pan and coil area is not isolated, and the condensate will not drain.
As for the corrosive nature of condensate, for some of the high-efficiency equipment, the manufacturers have pointed out that the condensate is highly corrosive. They state that the trap and drain should be ABS or PVC and not cast iron or copper.
Horizontal Or Vertical?I am confused about the connection to a horizontal wet vent. If the lavatory is run below the floor to connect to the main drain for the water closet, do I have to connect the lavatory drain on the upper half of the main drain? My thoughts are that flat vents are not permitted and the code always requires the vent to connect to the top half of a horizontal drain. Is this correct?
Julius replies: It depends on the code adopted by the jurisdiction. The International Plumbing Code and National Standard Plumbing Code will permit you to connect on the horizontal. While you state that this would appear to constitute a flat vent, remember that the vent also serves as a drain for the lavatory.
The main concern for flat (horizontal) venting is the increased possibility of having a stoppage in the vent pipe. When the vent also serves as a drain (hence, the expression wet vent), the same possibility does not exist. The lavatory waste is constantly cleaning the vent for the water closet and bathtub.
If you are in a jurisdiction that adopts the Uniform Plumbing Code, realize that horizontal wet venting is not permitted. They only permit venting when the main piping is vertical. Only the fixture drains (from each individual fixture) can be piped horizontally.
Winter In New England> We are in an area of the country that can be exposed to cold winter temperatures. While I normally do not pipe any water lines in the outside wall, the home builder insisted on a shower with the shower valve located on an outside wall. We plan to insulate the hot and cold water pipe and locate the building insulation on the outside of piping. Is this adequate?
Julius replies: Your proposal has a major flaw that many contractors fall into. You stated that you plan to insulate the hot and cold water piping. While that may sound like a good idea, it is one of the worst things you can do for piping located on an outside wall. By insulating the piping, you are keeping the building heat away from the pipe.
Think in terms of heat flow. The heat of the home keeps the piping from freezing, not the temperature of the water in the pipe. By insulating the pipe, you effectively block the heat from the home. Thus, the pipe can freeze faster than if there was no insulation on the pipe.
I recommend that any pipe on the outside wall (or in the ceiling) not have any insulation. I would rather have the pipe uncovered with the building insulation located between the pipe and outside wall. Realize that in some climates, this still is not adequate.
In the Chicago area, where I am located, we would think a contractor was an idiot if he piped any water lines on the outside wall of a single-family dwelling. That doesn't mean it is not done.
You really have to know your climatic conditions. If the pipe is on the outside wall, the one thing to immediately consider is increasing the amount of insulation in the wall cavity in which the pipe is located. I also recommend adding more insulation into the adjacent wall cavities.
Again, the increased insulation still may not be adequate. In those instances, the pipe can be protected by a self-limiting heat tape. These new tapes only use energy when the temperature drops below 40 degrees F. When using these tapes, you must insulate the piping.
Knowing your climate, my recommendation is to be careful with any piping on the outside wall. Lawsuits for water damage from frozen pipes can get expensive.
Illegal SubstitutionThe engineer for a project specified an overpriced, lousy shower valve for a nursing home. We changed the shower valve to a better valve that is half the price. I was told that to do so was illegal by the plumbing code. What gives?
Julius replies: You were told correctly. It is illegal according to the plumbing code. That may sound strange, but let's follow the legal trail that can either keep you out or get you into trouble.
The shower valve that you installed probably met the technical requirements of the plumbing code, hence, you assumed that it would be an acceptable swap. However, the technical requirements are only one segment of the code.
One of the key factors in code application is the trail leading from concept, to permit, to certificate of occupancy. Any construction on a piece of property must first be approved by the property owner. (Imagine if we start a building without the property owner's permission.) The owner is responsible for retaining professionals to prepare plans for construction. If the building is other than a single-family dwelling, every state in the nation requires plans to be prepared by architects and/or engineers.
The architects and engineers are bound by law to prepare plans that conform to the code, including the plumbing code. The specifications that accompany the plans are a legal part of the overall construction documents. The code requires these documents to be submitted to the Building Department before a permit can be issued. The plans are reviewed for conformance to the code.
Once the plans are approved, a permit is issued for construction. Sometimes, the plumbing contractor is required to take out a separate permit. The administrative provision still indicates that the approved plans are a part of the plumbing contractor's permit.
The stipulations of the permit are that the building must be constructed in accordance with the approved plans. If a contractor deviates from the plans, technically he violates the code. If a deviation is required, the legal way to address this is by having the architect or engineer modify the plans (or specification) and submit the revisions to the Building Department. Then, the approved plans change and the deviation becomes legally acceptable.
When you change the shower valve without changing the specification by the engineer, you violate the provisions of the code requiring you to install the plumbing in accordance with the approved plans. To be legal, the engineer must change the specification.
I realize that changing products without the engineer's permission occurs every day. That does not make it correct or legal. Let's jump down the road a few years. Assume that the shower valve you installed fails. Maybe it leaks, causing significant water damage, or perhaps the valve scalds an individual. Lawyers get involved. Lawsuits spring up. The first thing the lawyers do is review the plans and specifications.
As a plumber, you assume that the valve manufacturer is responsible. However, the manufacturer goes to the plans and says, "Hey, the engineer never specified our shower valve. Hence, you shouldn't have installed it." The engineer reviews it and says, "Hey, you didn't install the valve we specified. As such, you acted as the design professional for the project. You are not licensed as a professional engineer, thus, you violated the engineering act."
I could go on, but you get the idea. In this scenario, you become the individual that is solely liable for the failure - even the manufacturer is off the hook. So the long and short of it is, install what the engineer specifies, or get the engineer to change the specifications.