Prehistoric HVAC engineers 3

[Stormxtc]

Hi all,

I have been working in the HVAC design industry for the last 3 years only. Before that I was woking in an industrial environment which is totaly different to what I do now.

Over the 3 years I have come to the conclusion that the HVAC industry is extremely primitive in dealing with creating a comfertable environment for people to live in.

We use a multitude of fans, coils, heat rejection equipment, control systems, ductwork, pipework, cabling, return air paths, supply air paths, outdoor air, plenums and this and that etc etc etc. just so we can be comfertable.

We use all of these equipment, which generally do not have a very high efficiency rating and even less so when they try to opperate together, to sustain the indoor air conditions at 24degC and 55% RH. To me this is an increadibly inefficient system, very cumbersome and even prehistoric when you consider other engineering fields such as automotive and aeronautical engineering which have soared since their first invention.

Are we HVAC design engineers guilty of being lazy in pushing the fronteer of HVAC to its limits. How many of you are forcing the envelope to eliminate this cacaphony of equipment and invent better ways of conditioning the air?

When we look at the energy consumption of each individual equipment, and then the AC system as a whole, and then the AC system for the whole building, and then all the AC systems in all other buildings in our neighbourhood, and in the whole city, and the whole country, I am dumbfounded at the energy we waste JUST TO KEEP US PEOPLE COMFERTABLE. We HVAC engineers contribute more to the greenhouse effect than any other engineer.

So, my question is, is there anyone out there who feels the same as me with regard to the waste in energy for the sake of comfort, and if so are they looking at alternative ways to achieve comfort at higher efficiencies?

I know that there has to be a better way and I'm curious as to which of us HVAC engineers will first come up with it.

Look forward to your thoughts and comments,

StormXTC

 

[MintJulep]

Storm,

Have a look at

http://www.rmi.org/

One of the folks from the Rocky Mountain Institute delivered the keynote address at the ASHRAE meeting a few years ago. Very interesting presentation.

 

[imok2]

Storm, Energy management is very big in this Country Are you familiar with the Asso of Energy Engineers? Take a look!

http://www.aeecenter.org/

 

[lippy]

hELLO,
I too am a relatively new ME to AEC/MEP but have been an engineer for 15 years. I do agree with you and have experienced "shock" at energy waste for indoor air quality.
I see that LEED's and "Green Building" philosophy is addressing this somewhat. I think we need energy "hawks" on big projects to bring effeciency right down to the component level. Most of the specs I read and follow do not even mention energy effeciency. And unfortunetly there is a prevailing attitude, "We're not paying the electric bill". Buy the way, what temp. does your house go down to at night? Mine is 50-55F in the winter. I disconnected my central air and put in a big attic exhaust fan.

 

[ChasBean1]

I don't see much waste in the design or newer equipment. The design needs to meet ASHRAE ventilation guidelines that were developed for systems to operate, at a minimum, just above perceived air quality and odor thresholds. We trashed HVAC during the 70's energy crisis, and re-established minimum values based on exhaustive trials after perceived unhealthy environments.

There's also a need to dehumidify to prevent mold growth and to add and extract enough air to maintain temperature at a comfortable level and remove odors. If we decide to blow this all up and start again, we'll eventually end up pretty close to where we are now. Accomplishing the ventilating, cooling, heating, and dehumidifying will take X amount of energy regardless of whether you do it by centrifugal fan, hot water, and chilled water or by a magnetic impulse air moving machine and a fusion coil (made up of course). One might be a little more efficient than the other, but the majority of energy used is to accomplish the goal itself. To change the goal, we trash current guidelines, and here we are in the 70's again. There've been huge advances in fan design, coil design, boilers, chillers, flow control, and automatic controls - but if you walk into some building and look at the fan squealing away and the rattly duct work, I can see how you'd perceive we're still in the dark ages in the industry.

Where I see the most waste is in setting and maintaining building controls. Just about all newer building automation system packages have wide range capabilities in the areas of timed energy setbacks. For new construction, most contractors barely even make these systems functional - they fall far short of optimizing the systems based on occupancy schedules, etc.

I'd like to see the controls area of the industry improved. Right now I think it's a competitive bid issue, and I think some ATC firms are losing their shirts just trying to make things barely functional. Fully programming timed setbacks could save a bundle...

 

[lilliput1]

ANSI/ASHRAE/IESNA Standard 90.1-1999 Energy Standard for Buildings Except Low-Rise Residential Buildings addresses your concern. I have been an HVAC engineer for 29 years now. I do not exactly share your view although I am also concerned about energy waste. I do not find HVAC for human comfort wasteful if the building meets the above standard. HVAC increases the efficiency of human workers. However I have seen excess Architectural showmanship drive HVAC cost up. Then there are manufacturing processes (you should know this from your industrial background) that go way beyond because of the importance of protecting the product. Manufacturing clean room spaces require tremendous HVAC energy!. Typical minimum air changes per hour in Pharmaceutical Areas is 20. Class 100 clean rooms require about 635 ACPH. Compare them to about 7.5 ACPH or 1 CFM/SF for office spaces!

 

[Accystan]

Storm:

You pose some very good questions. I like your attitude.

I can only speak for the commercial/residential/institutional (not industrial) side of things but one of the things that holds us back, particularly in North America (and in many other parts of the world), is our bottom line/first cost/lowest bidder mentality. We live in a Walmart country and have a Walmart attitude; the bottom line is what counts most of the time. I’ve lost count of the number of projects I’ve worked on where innovative, energy efficient systems are considered initially, only for them to be dropped when the first cost (as compared to the LCC) is seen.

I would also point out that many, maybe even most, items of equipment and systems are much more efficient than they were 20, 50, 100 or 150 years ago. If you look at a steam plant from the mid 1800’s you won’t see any heat recovery. Plants ran with an overall efficiency of 12% to 15% and nobody cared; fuel was cheap. But the rules were the same then as they are now. Why spend $5,000 to install heat reclaim eqpt. just to save $1,000 of fuel? Just let it go up the chimney.

Whether centrifugal fans, or cooling coils (for example) are much more efficient than they were 25 years ago is something I can’t say, I imagine they are. But one item, which has improved the efficiency and performance of systems enormously, is the control or building management system. Huge strides have been made. These systems are infinitely more efficient and capable than they were 25 years ago when the best you got was a time clock. Maybe a piece of equipment is only 60% eff. now as compared to 50% back then but if your control system is able to run it only when needed or cut back its output to meet demand you’ve made progress.

I suggest you unroll some plans from some project which was designed and built in the 50’s. It’ll be an eye-opener and you’ll see that there has been progress.

As I said, I like your attitude. The industry needs to be questioned and examined and challenged. I also like the quotation from Oscar Wilde. “I am not young enough to know everything.”

You may want to post your question/thoughts on the “Where is Engineering Going……” forum.

Cheers.

 

[ClydeMule]

If you are saying that we are not doing as good a job as we could be in terms of energy efficiency in the HVAC field, then I say I agree with you and will refer to the prevous responses.

If your point is that energy expenditure for the sake of comfort is inherently wasteful, well then you are into more of a philisophical discussion than technical.

There are a lot of things that we can do without, but we don't want to. Some of them may be considered frivolous, or some may be considered necessary for our society's health. For example, I would be way less comfortable if we did not have a system to process domestic raw seawge, but we would save a lot of energy. Same with the treatment of my drinking water. We could save a lot of money on the distrubution, filtration, and purification, but on the other hand I would have to carry water from a long ways away, or have to live with water that will make me shit like a goose.

In the HVAC/R world, the production of items like Ice Cream, Beer, Wine, milk, and the storage and freezing of food is EXTREMELY energy intensive. These are items we could arguably live without, but do not choose to.

You must define scope of what is useful or wasteful. If all of the above items I mentioned are considered unnecessary, then a system 100 times more efficient than what is currently done now would still be considered inefficient and wasteful.

To develop energy efficient systems we must reference what we are currently doing for a given application and work from there.

It's like talking about fuel economy in an RV. Fuel economy for an RV sucks. But you can't compare it with a Honda civic. If you are striving to increase fuel efficeny for an RV you must compare against other RV's. 12 MPG is lousy fuel mileage overall, but if my RV got that I would be ecstatic. BTW I have a 28' fuel hog in my driveway, anyone interested.

Regards,

Clyde

 

[DouginMB]

I agree with the original poster to some degree. Standard 62 was implemented back in 1989, but energy recovery technologies have lagged way behind. How long did it take many of the old salt engineers here to specify heat wheel and heat pipe systems?

Also, it took a long time for the big names in chiller manufacturing to endorse variable primary flow chilled water systems. The technology for it could have been implemented 10 years ago, but no one stepped forward until the last 5 years or so.

And take kitchen exhaust hood systems. We're only now seeing articles in trade magazines discussing operating fans on heat and/or gas flow meters. How long ago could this have been implemented?

Of course, the flip side is that manufacturing can absorb mistakes easier than consulting engineers. In other words, they can take risks that may not pan out and may not miss a beat. If I take a risk on a new expensive energy savings technology and it doesn't work as advertised, i have to pay to get it fixed or risk getting sued and losing my business. I'm not sure industry faces that same risk. At least not when it comes to environmental comfort.

 

[Stormxtc]

Hi again everyone,

Firstly, my apologies for my late reply and being such a bad host!

Secoundly, our unofficial company moto is:

"Would you rather have X amount of dollars hanging on the wall or in your pocket?"

This is how we approach our design, BARE MINIMUM, and I work for one of the better building services consulting companies in Sydney. Emphasys is placed on meeting the standards (be it ASHRAE, Aust. Standards, BCA etc.), so long as the design complies with the standards no one can complain/dispute our work. We justify our energy waste by hiding behind standards, most of which have not even been updated to reflect current needs (eg. car exhaust emissions are approx. 30% less today than they were 15 - 20 years ago, however, because standards have not been updated as yet, all Aust. design engineers over-design their systems to comply with old standards - in the mean time energy is wasted).

Thirdly, we currently tend to design buildings from the outside in, meaning that architects design the building shell and then we get involved and try to suit our services to the space we have been allocated. I don't need to tell any of yu how difficult that job is, especially co-ordinating hydraulic, electrical, mechanical and fire services in a 300mm ceiling space.

We need to design buildings from the inside out, meaning that we should start the building design with the services engineers first and finishing with the architect! That ought to open a few cans of worms!

I agree with most of you in that the controls side of our work has progressed in leaps and bounds. And so it should, with the amount of money invested by companies on R&D, but what about HVAC R&D? Who is looking at R&D in the HVAC industry taking into account the whole HVAC system, not just individual equipment? Certainly not us consulting engineers, we are too busy designing to the BARE MINIMUM!

Accystan suggests that developers dont want to spend $5000 to save $1000. According to our old measuring scales, that would be correct, but not with todays scales. If only you Americans would sign the Kyoto protocol, then we would have emission quotas come into play and the whole playing field would change.

Good point with the comfort part Clyde Mule, I couldn't really live without my cold beer either!

I think it is our approach to design that may also benefit with a bit of a polish. Totally isolating an occupied space from outdoor conditions takes a great deal of energy as lilliput1 has pointed out. But what about using the potential of ambient conditions (since ambient conditions are neither bad not good in engineering terms) when it suits us to eleviate some load off our energy consumption? This is nothing new, however, it is rarely applied.

I think DouginMB gives good examples of our laziness as HVAC engineers in pouncing on new technology when it is available in our search for better performance. Why not use cyclones (the same principle as Dyson vacuum cleaners) for outdoor air filtration, it's widely used in industry to seperate dust from air?

I certainly don't advocate the scraping of all current standards and starting all over again and agree with ChasBean1 that we have come a long way, but our clients are ready for new developments in the HVAC industry and the current technical environment is ripe for us to make good use of what's out there.

Finally, I would like to thank MintJulep and Imok2 for their suggested links, thanks guys.

Just a few things I quickly had to get off my chest,

Thanks all,

StormXTC

 

[gaffatape]

Storm,
Further to what has already been written in reply to your post about things that have been done, and are being done. Have you checked out the Turbocor compressor.

http://www.turbocor.com

They say they are cutting energy consumption by up to 60%, which is a huge amount considering compressors draw a large proportion of the energy in a given system.
Obviously people out there are starting to think smart, by making extremely efficient machines now. hopefully the rest of the industry will follow.

 

[billygoat22]

Wow!, thats the first time I heard an engineer take credit for a mistake. My experience is to see a set of plans with hvac, firemain, electrical,etc. installed in the same space without any coordination. They all occupy the same space simutaneously, which can't happen in the real world.So you can imagine what the installed stuff looks like- and performs.
Simply building "inside out" would change everything. HVAC equipment must be accessible for maintenance- to be cleaned and repaired= efficiency. The fewer turns and restricions lower fan power use, same for long refrigeration lines vs compressors. Locating all the duct inside the conditioned envelope as opposed to an attic can lower system size and thus power use 10% without changing a single other component.

 

[MarauderX]

To add a quick note...

Getting your system built properly is where many of the conservative numbers come from. Having each system built specifically to each application isn't the same as perfecting a car, as each one must be built for each application. Granted the goals are the same in each, but for a contractor to put it together twice the same way is nigh impossible.

 

[BravoCompany]

As engineers we share the responsibility of creating energy minded systems only in part. Taking a holistic approach at looking at HVAC systems from design to construction to commissioning to operation, one begins to realize why the situation is what it is:


1. We live in a modernized world driven by money in many respects, and first cost seems to win out time and time again with energy conservation falling to the way side. I have been involved with life cycle cost analysis on several projects, and to be honest there simply is not enough trend data available, to be confident in the results, at least in my experience; I believe this is an area that engineering associations need to devote more time and attention.

2. Systems which provide higher degrees of energy conservation typically require higher degrees of engineering attention in the design phase, which comes at an additional cost which must be absorbed by someone, hopefully not the designing engineer.

4. They require a higher level of trade coordination due to the complex nature of associated controls. This can lead to disaster if not properly coordinated. Due to the complexity of controls, commissioning of such systems requires a higher level of attention and documentation, at additional cost of course.

3. These systems require a higher degree of skilled facilities personnel, which could mean many more man-hours of additional training and education, in addition to the increased man-hours required to simply operate and maintain such systems, at additional costs of course.

The only true solution to this problem is a highly complex one that integrates all of the above. The business world will never implement such strategies without some incentive associated with more energy conscientious systems. I am afraid this will in the end need to come from a source such as government subsidy or mandates. I believe they have bigger fish to fry at the current moment.

The industry of power generation is plagued with a similar scenario and the energy consequences in this arena are of course much more substantial.

Sorry for such a long thread, but the bottom line is that we do what we can do as HVACR engineers but it is only part of the bigger picture.

 

[DouginMB]

Great post Bravo. You pretty mcuh nailed it, especially the part about life-cycle cost analysis. Historical data for different building systems is scant at best.

 

[ClydeMule]

Sometimes there are other design factors that wind getting a higher priority than energy efficiency.

One example that I have run across recently is the use of glycol chillers for refrigeration. For market refrigeration, a lot of utilities will give you rebates to get rid of glycol systems for cooling and go to DX or liquid overfeed systems since they are more energy efficient. However, there is actually a trend to move to the glycol systems because of refrigerant issues. In fact Hussmann calls this there PROTOCOL (as in Montreal) series. They are marketed and percieved and more "environmentally friendly" becuase the require much less refrigerant, even though they consume more energy.

I don't throw out this example to rebut the previous statemens which I agree with. This is just a perspective from the reefer world.

Clyde

 

[DRWeig]

Guys, this is a great thread! As an EE who did a lot of power/lighting/communications until I got into HVAC/R, I have always been perplexed at the following phenomenon:

If you give a blank set of floow plans to ten different electrical engineers and ask them to design power distribution and lighting, you'll get ten very similar results. It's not too difficult to optimize power distribution costs, and unless there's an architectural directive to do some fancy lighting, we all follow the same standards.

Now give that same floor plan to ten different mechanical (HVAC/R) engineers. You'll get chilled water on some, dx on some. You'll get variable pumping and constant volume pumping. You'll get VAV, VAV with reheat, constant-volume air, and maybe even dual-duct. You'll get dedicated ventilation, fixed ventilation, and demand-controlled ventilation. You'll get water cooled condensing and air cooled. You'll get rooftop units and thru-wall units. You'll get oval duct, rectangular duct, and round duct. Even within a chiller plant, you'll get high-pressure machines and low-pressure machines, maybe even absorbtion. For heat, you'll get one big boiler or many small boilers. It goes on and on.

If the design fee were large enough to allow a thorough analysis of life-cycle cost, IAQ, and energy use, those ten mechanical engineers would come a lot closer to a similar, optimized design. Unfortunately, nobody is willing to pay for that. Even when they are willing to pay, the consulting firm is apt to save the money by cutting the analysis corner. Most of the time, the designer is in such a hurry that he just slaps in whatever he's most comfortable with.

Just my two cents worth. This is the most fun (and possibly useful) problem I've seen in this forum! Good thoughts, all!

 

[Stormxtc]

Hi again all,

I came out of a meeting with one of the biggest developers in Australia (Multiplex Constructions) yesterday where we presented the developer with a brand new idea which was originally researched and developed by NASA to remove Volatile Organic Compounds (VOC's) from air.

NASA scientists claimed that plants could remove large amounts of CO from air in a relatively short time. We decided that this would be a great opportunity to apply such a new technique to purify (and filter) outdoor air supply into a building which is currently located between two major freeway overpasses and right next to one of two tunnel exhaust stacks (in fact the stack will be attached to the building).

We proposed the construction of a "green house" enclosure filled with plants on the south facade of the building through which we would pass outdoor air with high concentrations of VOC's. Our aim was to purify the air of all VOC's and dust by the time it reached our plant room on the roof. We called this air "Green Air" which would then be supplied to the building.

Such a "green air" building would set new standards in building design, it could change the way architects and engineers work together. It would be a step toward designing a building from the "inside out" where the engineer takes a greater role in the final shape of the building.

However, immediately after our presentation, the first question asked by the developer was "how will this save me money?!" Where do I start to explain...???!!

That is why I have called this thread "Prehistoric HVAC Engineers". For all my study and experience and knowledge of the sciences, I cannot come up with an arguement that is so good that the head of this developer will spin and make him beg me to realise our green air proposal. I still feel that HVAC engineers have not been active enough to push for viable energy efficient systems that will turn the heads of developers and give some decision making power into the hands of engineers who have the ability to, hopefully, be more environmentally efficient. Right now we just satisfy their needs.

I do agree, however, that great progress is being made and that perhaps in the future we HVAC engineers will have a greater say in the direction building designs will go.

My apologies for another long post,

Storm.

 

[billygoat22]

I read a paper over the web one time- Fisk paper on iaq, something along that line. It showed the economic benefits of how improved iaq affected the performance of office personnel

 

[MarauderX]

Good dialogue going here...

Saw a note about life-cycle costs narrowing HVAC engineers to similar designs and disagree. I have done numerous life-cycle cost comparisons and know that the numbers for each system can be estimated to go in a way that you wish. Having done it for both the USA and overseas I realize there is greater value placed on those numbers outside of the USA. In my experience, the USA is worried more about first costs as most building owners tend to sell the place in 5 to 10 years; owners overseas tend to keep properties on average for 20 or more years.

I have seen mandated cost analysis for USA government projects go right out the window when a contractor lowers the first cost in order to put his system in, despite the fact that two other designs beat the energy use, not marginally but substantially.

Overall, I would say that HVAC engineers have more disagreements about what is good, better, and best design than many others, and perhaps it has to do with familiarity, but I wouldn't say it has to do with life-cycle costs.