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Letters to the Editor


Mr. Kraut, I recently read your article about hot water balancing


in the December 2010 Plumbing Engineer magazine. I found it to be very informative, especially considering that I haven’t had much luck in finding recirculation examples. I would like one thing clarified. In the para- graph under the heading “Flow rate,” I noticed that you found a heat loss of 1,059 Btu/hr, but in the calculation below to find the required gpm to overcome the heat loss you used 1,236 Btu/hr. Was this a typo? I am currently putting together a spreadsheet for calculating heat loss and re-circulating pump requirements and want to be sure that I fully understand your example. Also, your article discussed balancing issues during


low flow situations. In your experience, what have you found to be the best balancing valve for low flow appli- cations? Thanks, Ben Shappie Engineer, Plumbing Group


Ben, I appreciate your feedback. The 1,059 in the article is


a typo. If you check my math, you’ll see that it does in fact add up to the 1,236 Btu/h that I carried into the next equation. Thank you for catching this. Peter Kraut, P.E. President, South Coast Engineering Group


Ron, Is PVC an acceptable vent material for flue gases?


This is an issue that we have been dealing with in Canada for years now. Our codes were revised, forcing industry to use ULCS636 venting. For the sake of time, there are just far too many items and comments to men- tion, but I read your article in the May 2011 issue, and you are right on target with you facts and assessment. This topic is one that the industry has failed to openly discuss and debate and one that some want to just die and go away. Everyone should be pleased that you had the courage


to set this out in the light, because too many want the issue to remain in the shadows. Thanks, Ron, great arti- cle! Keep up the good work. D. Brian Baker President, Custom Vac Limited


Dear Editor, I read your article touting fire sprinklers in homes,


and I see the advantages of having them, as they will probably reduce the number of lives lost in home fires. I do have several items I consider important about them. 1. The cost will be high for the builder. 2. How long will it be before the number of lives


saved can be measured? At the present time, we have a huge number of homes in existence without sprinklers. Retrofitting them would be very, very expensive, and they are the ones in which the fires occur. Hence, lives saved will not be saved. 3. Who will maintain the systems after they are


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installed? Will the homeowner do it? The landlord? People do not maintain their smoke detectors. What will they do when maintenance goes beyond just replacing a battery? 4. What will happen to seasonal homes? These homes


may be located in cold climates, and they may have no electricity or running water for part of the year. They may be used occasionally during the winter and then have the electricity and water drained. In that case, many people will simply disconnect the fire system and never reconnect it. If it is a wet system and the area tem- perature gets to -25 degrees, there must be antifreeze in the system. What will that do to the various parts? A dry system requires a much higher installation cost and maintenance, so those parts would also be a problem. 5. In some areas, the electricity is supplied by the


homeowner and is not a 24-hour-a-day item. This means that water may not be available when needed. As you can see, these questions are not addressed by


passing laws; there are many situations in which things are much different than the situation in cities, where most of the people passing the laws live. I have a house in the city built in 1907 and a summer home in a really rural area, which I use for a week for deer hunting and for Christmas, as well as in the summer. That is the rea- son for my concerns, and I hope that you will consider how they should be addressed.


Edward Downs P.E., retired June 2011


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