As I said before, I've also heard arguments for and against pnuematics and DDC
In commercial applications pneumatics are history,they were tried and convicted in late 1970's-early 1980's, pneumatic controls were fine, very simple to figure out but there are lots energy saving things DDC controls can do and pneumatics cant.
a BTU out of electric heaters cost more than any other source, as a rule electric heat is the last card on the table unless you own the power plant or live in a subsidized area.
As an aspiring building engineer, I find it surprising to see a newer building with an onsite staff. The newest buildings are all computers automated, thus eliminating the need for a large staff of bldg engineers to tweak pneumatic thermostats and calibrate heater boxes. Unfortunately it seems many building owners prefer outsourcing rather than an onsite staff with a brand new building. With older buildings, a staff is needed because of things like boilers, pneumatics, etc
Don't take this the wrong way..
Here is the problem with this statement..
Think about all of the systems in a highrise building.
Basic plumbing; Toilets, touch less sink fixtures, domestic water pressure pumps, fire protection systems, irrigation systems. Non of these systems can be automated to the point of stand alone.
Comfort mechanical systems; boilers, chillers, air distribution, IAQ, exhaust systems, network room air conditioning. Who maintains them C3PO?
Janitorial; Window washers, carpets, paint, basic cleaning, trash removal. Automate that and you will be the worlds next billionaire...
Other mechanical; Elevators, automated doors, emergency generators, parking garage equipment. All things things seem to be engineered to be unreliable.
Safety and compliance; Fire equipment inspections, ADA compliance, handicap parking compliance. There are times that on site personnel need to be present just for insurance purposes.
All this before we even start talking about LEED Certified buildings.
I think you need to go do some homework.:putergreet:
A friend of mine worked for a while as an engineer at the Hennepin Co. crime lab and morgue in Mpls. CSI! They had 5 penthouse mounted air handlers. An air cooled chiller on the roof, city chilled water and steam. The steam was used to heat water to pump through the air handlers. The day I was there visiting him it as 50 something outside. He was cooling the place on outside air except for the morgue. The chiller cycled to keep it cool. All controlled by a PC. If someone wanted temp changed, he did it on the PC. Someone was always on duty at least during the day.
Our suburb has built a lot of schools lately. Every one has boiler stacks sticking out. Usually air cooled chiller.
I appreciate your interest. Your experience in the field shows.
I have had the privilege of touring several class a office towers. I believe that I also mentioned that I was previously an apprentice with the onsite staff at a office tower.
After spending nearly a month with the crew I understand the variety of calls a building engineer might experience during a typical workday. You are right, it is necessary to be a jack of all trades in nearly all areas. This is especially true for HVAC since over 50% of the daily requests are hot/cold calls. During my time at the property I also discovered the importance of preventative maintenance. Things like checking the garage and common area lights, cooling tower water levels, and chiller readings are essential for a well functioning building.
My point was that all of the buildings I have visited are over 20 years old. The oldest was a Chicago building built in 1904. My understanding for the reason such a large staff is needed is because the equipment is reaching the end of it life cycle. However, a brand new building has new equipment which does not need to be repaired, replaced or calibrated. Most preventative maintaince is done by the building management system. Anything else is contracted out.
I applaud your knowledge of this field, yet why would a newly opened building(with advanced technology) need a staff of skilled engineers when there are no tenant complaints??? Another factor is that the eqipment is far more sophistacted and self-operating than before. Out of all the buildings I visted only 1 had an engineer present 24/7.
Just because a building is old doesn't mean it has the original equipment. You'll see brand new chillers, controls and everything else in older buildings.
If you go in with the idea that new equipment doesn't need to be repaired, replaced or calibrated, you're going to be in for a world of hurtin.
The point I was trying to make is that these newer buildings don't have type of complicated equipment seen in buildings of the past. There may be exceptions, but a newly constructed building isn't going to have thermostats to calibrate, radiators to adjust or boilers to clean. Everything is done by computers now. With compact equipment that doesn’t require large mechanical rooms. (On a side note; If you go back far enough some buildings had one or more mechanical floors. That is something that would never be done today.)
Another member of this forum stated that a newly built building isn't going to take up leasable space for a boiler. Hence the heat strips and heat pumps. It seems new buildings are solely unitary equipment. Since water cooled chillers need space for a plant and a cooling tower, DX units are now installed instead.
You're could'nt be more wrong... 1 trade center has how about 9 floors dedicated to mechanicals. You still need space dedicated towards utilities. Electrical distribution, life safety systems, generators, house pumps etc. How much space do you think is dedicated to a small dx unit per floor? And now if you multiply that by 30, 40 or maybe 50 floors, or in some case more? Giving up space towards mechanicals is unavoidable.
An old boiler could be retrofitted. I've seen plenty of old kewanees with brand new duel fuel burners installed. If you think the equipment of the past is more complicated than the equipment of today, well, then you're a hell of a lot smarter than me. Have you every walked in a 4 seasons rooftop? The amount of stuff in there is crazy. The Sequence of Operation for that compared to my little pneumatic system? You really have no clue....
The OLD 1 wtc had mechanical floors. I doubt the new one will, because they are using DX systems.