Emphasis of manpower: HVAC/R Engineering vs. Plumbing Engineering 1

[pedarrin]

I am looking for observations/explanations from the forum about something I see in the AEC industry. I am putting it in this forum because I think it will be read by more people than in the Plumbing Engineering forum

I have worked for/with several AE and Engineering firms as well as mechanical contractors over a ~13 year span and find two things which seem to occur frequently in the AEC arena.

1) The AEC company usually has a mechanical department with many knowledgeable and competant engineers doing the HVAC/R.

2) The AE company usually has a mechanical department with few knowledgeable or competant engineers doing the plumbing engineering.

I have found that what usually happens is the HVAC/R gets done first or gets first priority and the plumbing gets done last or at the tail end of the project. And the plumbing usually not done correctly. I saw this mostly when working on the contracting end.

I have found that usually the plumbing is done incorrectly because either the engineer is not properly trained to do it right or he just does not have the time to do it right.

I am not saying that plumbing or HVAC/R is any more or less important than the other. Both are required for the building to operate correctly. But why is so much emphasis placed on the HVAC/R and so little placed on the plumbing.

This site has a HVAC/R forum and a Plumbing Engineering forum, but if you look at the size and number of posts on both, it is easy to see the disparity. I realize that HVAC/R is more complex but I do not think it is by much especially when you consider tha Plumbing Engineering can include site utilities and medical/industrial gases.

I am just looking for observations or explanations about this phenomenon. Am I wrong or are my observations somewhat on track?

Thanks in advance.

 

[spector]

No Sir, you have 20/20 vision.

Just consider the nature of the beasts.

HVAC/R by nature is a rapidly evolving science that will always offer new ways/methods to save energy. It promises to demand constant new discoveries in design, manufacture and install/maintenance.....Plumbing is kinda install to today's code and live with it forever.

 

[TBP]

I disagree, spector. The basics of HVAC hasn't really changed much. Find some 50 or more year old technical & engineering books, and take a look. Physics is physics. It doesn't change. There are certainly a host of new control jobbies and systems that keep coming, though. A huge percentage of these are un-maintainable, soon-to-be/already are obsolete & no-longer-supported-by-the-manufacturer, total, unreliable, crap. In the rush to embrace ever more complex control technology, a lot (and I mean a LOT) of folks and companies have totally forgotten the mechanical side - the one that actually DOES the work.

We have recently had the experience of being called in to a large industrial customers plant to look at a new HVAC unit, supplied and installed by a HUGE company that everybody in the HVAC field would know instantly. It was/is the biggest piece of junk I've seen in a long time. Every possible joint on and in this assembly leaked, including several that were factory welds. One leak was a SS Swagelok compression tube fitting. It blew apart under water pressure because they'd managed to use a metric ferrule on imperial tubing. The guy that works with me fixed all of this. He's a - wait for it - plumber. The HVAC guy (from the gigantic, well know HVAC outfit), spent most of his time handing tools to the plumber (who was wedged into the cabinet), and trying to keep his laptop from getting wet.

Plumbing 1, HVAC, no score.

 

[spector]

Well, the basics of plumbing haven't changed much either and won't untill the law of gravity is overturned. But I recreated the falling apple experiment for myself, and it convinced me. So, I doubt anything new in plumbing will come along soon.

There have however, been many recent major changes in HVAC equipment. Take a look at Trane's oil-less, lifetime charged R-123 CenTraVac chillers. They use ceramic self-healing bearings. Your plumber will feel like the Maytag Man once he is surrounded by those units.

Perhaps your plumber felt bored with his never-changing trade and decided to develope some mechanical skills and discoved all the other laws of Physics that HVAC must exploit, but plumbing can ignore.

Either way, please welcome him to the trade. Mechanical Science needs good mechanics.

 

[pedarrin]

spector,

I acknowledge that there are a lot of advances in HVAC. While not as many, there are also advances in Plumbing.

The mechanical realm also has codes it has to abide by to be proper. So plumbing is not alone in that.

Plumbing deals with a lot more than just drainage. It deals with liquids, solids and gases. It deals with heat transfer, fluid flow, etc. Plumbing does not ignore any laws of physics except maybe for quantuum physics.

All that being said, I realize that there will always be poor plumbing contractors and poor mechanical contractors. There will always be good ones also. There will also be good and bad engineers.

What I am trying to determine is why in the design phase, the plumbing tends to be an afterthought. This is what I have seen on far too many designs. I have seen designs where the HVAC is superb and the plumbing is abysmal; and it is done by the same engineer. That should not be.

 

[Vicsidhu]

pedarrin:

I agree that Plumbing is the ignored part in a Mechanical Engineer’s agenda. It is sad, but this is the way it is.

The industry responds the same way. There are far less design guidelines for the plumbing design available today. I personally have hunted in vain for literature, which can teach me plumbing design in detail. In universities plumbing is all summed up in one lecture if the professor is generous, otherwise it is fully ignored. I have, with time, educated myself about the subject, but would have preferred to have solid reasoning/education/support litterature for my design as I have for the HVAC.

It is unfortunate that we engineers ignore a major segment and have one sided approach to the whole issue.

Happy New Year,

Vicsidhu

 

[spector]

I Roger what you are saying....But the answer is rather simple-Plumbing design and install is driven strictly by code. When people get creative there and push the boundries, they end up causing problems that can be very expensive to correct. You literally 'bury' your mistakes and live with them forever....

So if you want to research plumbing, refer to the codes. If you want to make advances in plumbing, be prepared to challenge same in every jurisdiction. And then suffer as the plumbers attempt to catch up, but blame their mistakes on your design.

 

[pedarrin]

spector,

Respectfully, I could not disagree more with "Plumbing design and install is driven strictly by code". When an engineer has to hide behind a code for the adequacy of his design, he is not worthy to be an engineer and should have his license revoked. Does he stamp his drawings because they meet a code or because they are designed correctly?

The codes are the guidelines by which he designs his system. There are some requirements like placing cleanouts every 50 feet or sloping 1/8" per 1'. But he can place the cleanouts every 40 feet if he wants or he can slope it 1/4" per 1' if he wants. Take venting of sanitary piping. There exists a vast expanse of different ways to vent, all of which are allowed by code. It is up to the engineer to understand why things are allowed in certain situations and not in others.

For the most part, the code is based upon past plumbing practices which work for the most part and upon engineering research. For the most part, they are not arbitrary. The codes are not perfect, and sometimes difficult to change, but they are workable.

In the International Plumbing Code, there exists the section on "Alternative materials, methods and equipment" which allows the engineer the ability to truly design the system based upon engineering theories and applications. The problem is that too many engineers do not have a good grasp on the engineering principles involved in plumbing. They make mistakes and it does get buried. Then the plumber has to fix the design and/or the owner of the building has to live with it.

A potential downfall in this alternate design approach is the code official has to approve the divergent design. This is the sticking point. There are a lot of code officials who think that there is only one way of doing plumbing which is their way. This can be very frustrating to the engineer, because the design works but the code doesn't address it.

But another problem is engineers who push their weight around with code officials, making them feel inferior just because they may not have a degree. I have found this to be, by far, the most recurring cause for not allowing alternative designs. These guys may not have the technical training, but they do have a lot of experience in plumbing. They may not know the math behind the design, but they understand the principles involved. I've found that the vast majority, if the engineer treats them with respect, are willing to listen to alternatives to traditional plumbing.

The hindrance to non-code designs is starting to change, at least where I do most of my work. The code officials are being told by higher ups, that since the engineer stamps the drawings, the engineers are responsible and liable for the design and to let it go at that.

The problem, as I see it, and as has been posted, is that the educational system seems to ignore plumbing engineering. In the U.S. there is only one school that I know of, which at present is trying to get accreditation for a plumbing engineering degree program.

So, what usually happens is the mecanical engineer who is also responsible for the HVAC/R portion of the project gets stuck with the plumbing. He usually does not have the engineering based education to do the plumbing so he just reads the code and follows that. He does not really understand the principle behind the code so when something occurs which is outside of the code, he is over his head. Or because he has spent 90% of his effort on the HVAC/R, he squeezes in the plumbing with the remaining 10%. This is a recipe for disaster. This is the reason for my post to try to find out if I am understanding the situation or if it is just a localized phenomenon.

One good thing is The American Society of Plumbing Engineers (ASPE) is currently trying to put together a systemized approach to plumbing design with design standards and approaches. They are heavily involved in getting plumbing engineering into schools. They do have data books which are a real help. There also exists a few books which are very helpful.

 

[VEEKRISH]

It is good to look at so many points of view. I am from India, and we do not have any great codes for plumbing here. It is also very difficult to obtain any material on this. Like some one said, it is usually fit and forget situation. What is seen are the faucets and such like. A lot of attention is paid to this. Not much towards engineering. (Is it the same everywhere? )in the HVAC industry things are a lot better. Probably because, people depend on it to keep them cool!!!

 

[pedarrin]

Veekrish,

I know what it is like to try to find materials on plumbing engineering. I am a chemical engineer by education and got into plumbing more from an economics perspective than a technical perspective. I got laid off from my job and had to "rediscover" myself.

I used the internet to find a lot of materials.

The following are the sites I have found most helpful. While they are "American", they contain a lot of information which can be used no matter where you are located. As spector has said, the laws of physics are universal. It flows downhill in the U.S. and it flows downhill in India. Something else is universal. If you can connect to the internet, you can get information which may not be available in print in your location.

http://www.pmengineer.com

http://www.pmmag.com

http://www.plumbinghvac.com

http://www.tmbpublishing.com

http://www.plumbingweb.com

http://www.aspe.org

The first two sites include focus on all mechanical aspects but have a good focus on plumbing. The third is a combination. The fourth and fifth are just plumbing. The last one is the web site to American Society of Plumbing Engineers (ASPE). They do have international members who probably are interested, like you, in the information the organization has more than membership in a chapter. Through ASPE, you can obtain books which are really helpful. I do not know what it would cost to ship them to India, but they are helpful to me, so you may want to think about them.

Hope they help.

pedarrin

 

[TBP]

A great many people imagine that fields they don't know much about are somehow very simple. The see one aspect of it, and assume that that is all there is to know. Lots of these people also assume that unless there's a PLC hanging on a piece of equipment somewhere, it must be some sort of antique.

I'm not a plumber or HVAC, but I rub up against both, regularly. Some of you HVAC guys need to get over yourselves. Dampers are dampers, fans are fans, ducts are ducts, refrigeration is refrigeration. Fundamentally, very little has changed in 100 years.

The most glaring example I can think of, of what is considered "plumbing" being shoved to the back burner occured a few years ago in Walkerton Ontario. 6 dead, and a whole town (literally thousands of people) sick. Hundreds were ill enough to require hospital treatment. Quite a number of these people are STILL suffering health problems directly related to the incident. The electrical arm of the utility ran the waterworks/sewage side. Well, after all it's JUST PLUMBING, y'know. I mean a monkey could do it.

When was the last HVAC failure that caused that magnitude of death and illness?

 

[spector]

I just linked to an ABC news clip of that event....Scary, huh?

My town recently managed to connect an underground sewer main with the water main.....Even tho the two pipes are located at different depths and of different size and materials, the plumbers worked at it till they were satisfied and reburied it....They sure were surprized to discover their mistake. The lawyers are still lining up the cases.

 

[pedarrin]

As I have said, there are good plumbers and obviously in spector's town, there are bad plumbers. Talk about "don't drink the water"

I have never said that HVAC/R is less important than plumbing. I work around a lot of HVAC engineers and have nothing but respect for what they have to do. In fact, I would like to learn more about it. That is one reason I am on this forum. It definitely is a complex arena.

What I have tried to get at in my posts is that plumbing is neglected far too much, and trying to find out why.

You just have to look at some of the health issues that face plumbing:

E. Coli,
Salmonella,
Legionella,
Scalding,
Patients getting the wrong gas during surgery,
and the list goes on.

I am not saying that HVAC/R doesn't have any concerns. They have legionella concerns also.

I guess what I am really looking for is a refocus on plumbing engineering and design issues. It is not just about what flows downhill anymore. It is a technical field which requires engineers to give it the proper attention for the project and owner's benefit.

 

[spector]

http://www.johnmills.net/hvacshots/pages/lots_of_drains.jpg

Please go to the link posted above to see why plumbers doing HVAC is a bad idea.

The example is an air handler that can be installed in one of several positions....it is provied with drain connections for each. The plumber conected to all of them!

A+ for effort, but F- for common sense.

I rest my case.

 

[pedarrin]

spector,

I could not agree more.

That plumber had no business connecting to that equipment. Where I am at, you can have plumbing contractors who do just the plumbing, or you can have a mechanical contractor who could do either plumbing or the mechanical or both. I once worked for a plumber who was fairly good at "plumbing" but should not have been let within a mile of any mechanical equipment more elaborate than a toilet. It all comes down to training and experience and as you said, common sense.

The same can be said for the engineers who design these systems. There are some HVAC/R engineers who can design both very adequate plumbing and mechanical system designs. But, I hope you would be able to admit, there are some who should not be allowed to touch the plumbing design.

That is the main thrust of my posts. Why is plumbing engineering an afterthought in most, in my opinion, engineers minds?

 

[kck115]

Good topic pedarrin,
I find that plumbing is more of a hands on science.
You are correct in that cleanouts, drains, etc. can be placed anywhere vs. what the code stipulates.
However, tradesman and not engineers have pulled and cleared these 'problems'. The engineer may do a good job in layout, fixture count, etc. in accordance with code but usually doesn’t have the field experience so may miss some items.
I’m a Chem E also who’d a thunk plumbing.

 

[aharcourt]

Fascinating thread this. I have been an electronics engineer in the telecomms industry for 30 years, working in research & development labs, installing state of the art stuff underground, on the ground and in the air. With the demise of telecomms as an industry I saw pay rates dropping to new lows. I remember a wise sage on the radio (an American) who was a rocket scientist telling how he gets $25 an hour. He caled a plumber to fix a pipe leak at his house whose rate was $75 an hour. The rocket scientist's explanation was that every schoolkid is taught computers, and not one single schoolkid is taught plumbing. So there are more rocket scientists than plumbers.
So, when I couldnt get a job anywhere in the world as a telecomms engineer I retrained to be a plumber. Now I am earning the high rates I used to in the good old days of 5 years ago.
My theory is as follows:
1)the HVAC engineers HAVE to come up with new stuff all the time to enable the manufacturers to sell product.
2)they are thought of by the employers as cleverer then plumbers, therefore engineers specify, and plumbers do.
3)Plumbers wear overalls and work in s**t holes, engineers wear suits and work in labs. Therefore engineers get first shot at a job, plumbers follow.
4) I don't care: now I am a plumber it's me that buys my own Mercedes and the engineer that gets a company Ford.

If it's of any interest, I have sent computer data through 22mm copper plumbing (using microwaves) and data at 2400bps over wet string. Thats a bit faster than my intertnet connection sometimes.

 

[pedarrin]

aharcourt,

I like your perspective. Go where the needs are. I was once told that no matter how advanced the world gets, it will always need ditch diggers. Find something that somebody needs, get good at delivering it, and reap the benefits. If you are worth it, the money is there

I once knew a mechanical contractor (he could do both plumbing and mechanical work very well) who could run circles around any engineer when it came to seeing the big picture of how to make things work and fit in the field. He could tell you whether you needed a 3" or a 4" pipe (based upon the code). He could also tell you the 4" pipe would not work because it would not fit in the space allowed.

The contractor probably couldn't care less about bernoulli's (sp) formula, but he could sure make any piping configuration or orientation work in the field. He only had a high school education but I went to him to make solutions which would work rather than go to an engineer who had not much field experience. The engineer was too worried about getting his shoes dirty whereas the plumber... well you know what a plumber gets into. When it comes down to it, it must work in the field.

That is another thing I think is missing in the engineering curriculum: time in the field. Everything looks right on paper, but give it to a knowledgeable contractor, and he will immediately point out the "obvious" mistakes, all the while laughing about the "dumb" engineer. I have seen designs where sanitary piping, if put in according to the "stamped drawing" would end up below the ceiling because the engineer forgot to account for slope. I have seen a lot of similar "stupid" things done by the inept contractor.

As I have said before, there are good engineers and bad engineers. There are good contractors and bad contractors. Let's just try to be the best at what we are and try to learn to do even better.