New Construction transition from Boiler to Heat Strips??

[MHall]

Having toured many buildings, both older and newer I have noticed that all of the newer office skyscrapers built in the 1980s-present utilize electric heat strips for space heating rather than HW or Steam Boilers. Now if you visit an office tower or other commercial property built in the 1970s or before, boilers are often utilized for heating needs. It seems the building has to be over 30 years old before you will find boilers in use. In fact I know of an office tower built as late as 1981, which utilized HW heating boilers. However from about 1982 forward it seems that all new construction utilizes electric strip heaters.

Does anyone here have an idea what brought about this change in HVAC design??? The boilers provided a good source of heat for a large structure such as an office tower. I do not see why newer properties do not utilize them. I visited a 72 story tower, in my city. All 72 floors are heated by electric strip heat. Why not use a boiler in an application like this? The building was built in the mid 80s. We also have a 56 story tower, in our city. It was built in the 1970s, and has electric boilers. Is age really the issue?? Did HVAC engineers suddenly come to the realization in the 1980s that boilers were too antiquated and inefficient for new construction?? Any insight regarding this question is appreciated!!

Thanks.

[-80guru]

One can only guess. Sooo if I were to guess, 1. install cost. 2. Install cost and 3. Install cost. To add, there is flexibility and maintenance issues as well. You may also notice alot of buildings have installed packaged water source heat pumps, maybe not in the high rises but I have seen many in low rise buildings

[Pete838]

Install cost is considerably less, and for leased space there is little motivation for the building owner to install a high priced energy efficient system. At least until the new energy efficiency codes come on line and force more insulation, more efficient lighting, better HVAC, low-e glass, or a combination. Owner occupied buildings are more likely to have better systems than space for rent.

Recently I've seen a few more split system heat pumps in mid rise buildings. The reason was energy codes.

[DeltaT]

The cost or profits from leased floor space that a boiler would take up is one big factor. Plus remodels as in increasing or decreasing rented lease space is easier. The reduced install cost is also a big factor as had been stated. In certain locaitons with certain size boilers and certain size building a building engineer also is required and that get expensive for the owner if that is the case.

[MHall]

The cost or profits from leased floor space that a boiler would take up is one big factor. Plus remodels as in increasing or decreasing rented lease space is easier. The reduced install cost is also a big factor as had been stated. In certain locaitons with certain size boilers and certain size building a building engineer also is required and that get expensive for the owner if that is the case.

Good point, but couldn't the boiler be housed in the basement or penthouse?? That would not take up any tenant space.

Back to my original question. Why is it that buildings built 1970s and before almost always had a full boiler plant, regardless of the factors mentioned?? Was there any energy mandate in the 1980s that began to phase out boilers and begin the use of heat strips?? You have to remember it wasn't until the 80s that this change happened.

Thanks for your insight!

[Pete838]

Remember, the 80s also brought us POS cars like the Yugo and the K car. Petro fuels got really expensive in the late 70s and the big cars went bye-bye. I'm sure that had something to do with the change in heating.

[BaldLoonie]

Big office buildings need little heat. So long term, it probably doesn't pay to spend the big bucks on a boiler and piping just for a little morning warmup heat. Also less staff is needed on site without the boiler. And heat pumps, which were mentioned, would eliminate the need for strip heat since they can provide what little heat is needed very cheaply. You'll notice a big building with heat pumps will have the cooling tower running even in bitter weather since most of the suites will be cooling.

[DeltaT]

Good point, but couldn't the boiler be housed in the basement or penthouse?? That would not take up any tenant space.

Back to my original question. Why is it that buildings built 1970s and before almost always had a full boiler plant, regardless of the factors mentioned?? Was there any energy mandate in the 1980s that began to phase out boilers and begin the use of heat strips?? You have to remember it wasn't until the 80s that this change happened.

Add to that the lack of skills and the emphasis of set it and forget it management based on some type of software looking over all the equipment now not being maintained by skilled workers that pretty much aren't available anymore and the pressure to get the highest rent possible over the short term with the absolute least amount of costs to the building owner and it adds up to what we experience today.

Thanks for your insight!

That would mean a penthouse and/or a basement would have to be built and used for non rental space. Any floor space that is horizontal is considerer rentable so it's not going to be used for machinery for heating/cooling the building. And that is also why any new or remodeled building has the HVAC stuff in the ceiling.

Back in the 70's there was a completely different mind set. Machine rooms were common and necessary simply because unitary equipment did not exist. Plus labor was way more skilled, built up systems were the only way to go. Air handlers typically were centralized and the cost of labor and the way of doing business including the costs of doing business was much more humane as compared to today.

It was a era of skill, pride in workmanship, heavily built equipment that would last (as it has) for years and years and a completely different mind set. Most of the money spent back then was based on long term, long lasting investments with a steady economic growth with long term tenants of all kinds.

Now, it's build a big box, fill it with the working stuff in places that are extrememly hard to reach and out of the way of any floor space, tenants that are pushed to extinction by costs and regulations, economic factors that can drive anyone out of business in a few years and technology as an excuse for long lasting and proper performing equipment of all kinds.

[ControlsInMT]

Big office buildings need little heat. So long term, it probably doesn't pay to spend the big bucks on a boiler and piping just for a little morning warmup heat. Also less staff is needed on site without the boiler. And heat pumps, which were mentioned, would eliminate the need for strip heat since they can provide what little heat is needed very cheaply. You'll notice a big building with heat pumps will have the cooling tower running even in bitter weather since most of the suites will be cooling.

Can somebody say computers and flourescent lighting???

[MHall]

Excellent post. I agree with the points you have made here.

So it can be safetly said that any new building built today will not have a central plant??We have establishled that boilers are never installed today for heating in new highrise construction. Is it the same with chillers?? Are central plants simply not part of new construction for the reasons stated below??

Thanks

[fitzyfitta]

I think the climate in the buildings area has a lot to do with the mechanical design. I have yet to come across a high rise or any large facility in my area without a hw boiler for heating. There used in water source h/p systems, reheat coils, fintube baseboard, unit ventilators and many other applications. I rarely see electric strips.

[MHall]

I think the climate in the buildings area has a lot to do with the mechanical design. I have yet to come across a high rise or any large facility in my area without a hw boiler for heating. There used in water source h/p systems, reheat coils, fintube baseboard, unit ventilators and many other applications. I rarely see electric strips.

How old are the buildings you are refering to? Down here in Texas it is not uncommon for any building to be heated to boilers if the property was built in the 1970s or before. From the 1980s- to the present, it seems that all new construction is equipped with heat strips for space heating.

What part of the country are you in?? I would be very suprised to see an office building built in the 1980s or later that utilized a boiler for space heating.

As one poster pointed out, construction in the 1970s and before focused on quality rather the cheapness. Older buildings were construction with quality materials and built to last a lifetime. Given the fact that boilers were always installed in those days, it appears that a quality boiler was an essential part of a well constructed building. It makes sense; in the 1980s we entered the disposable age. Look at the homes from that time; cheap and shoddy construction (in my opinion) with cheap materials. I suppose office buildings were also being constructed with cheap materials. Part of this was to stop installing boilers and move towards a"cheaper" solution literally. If anyone has any thoughts on the matter I'd be curious to hear them.

THanks

[MHall]

This thread has also made me wonder how boiler manufactures such as Cleaver Brooks stay in business, with all new construction for the last 30 years using heat strips!

They probably still get a lot of business supplying manufacturing operations and of course replacement boilers for old buildings. However all new construction not having boilers for the last 30 years must have hurt their business a bit.

Boilermakers were probably a much large business back in the 1970s and before, when new buildings still included them in their HVAC design. It makes me wonder how many of the old companies are out of business. Just a thought though.

Any other info is much appreciated!
Thanks

[BaldLoonie]

Lotta new schools around here. Chillers & boilers. So maybe that's how the big boiler makers last. Or churches. We have a new 2M Fulton Pulse and a bunch of Carrier splits with air handlers in our renovated building.

In a big city, there's often district heat. Indy has one of the largest in the country. Most older buildings don't have boilers and get their steam from the district plant. About all new buildings in reach of their lines get their steam and chilled water from them. Many older buildings that lose chillers also tap into the lines.

[MHall]

[QUOTE=BaldLoonie;14631661]Lotta new schools around here. Chillers & boilers. So maybe that's how the big boiler makers last. Or churches. We have a new 2M Fulton Pulse and a bunch of Carrier splits with air handlers in our renovated building.

In a big city, there's often district heat. Indy has one of the largest in the country. Most older buildings don't have boilers and get their steam from the district plant. About all new buildings in reach of their lines get their steam and chilled water from them. Many older buildings that lose chillers also tap into the lines.[/QUOTE


What's interesting is that when it comes to office towers that are newly constructed, they do not want to seem to use boilers or district steam.I wonder why the aversion to district steam in new construction??? Is it for the same reasons new office buildings refuse to install boilers for HVAC?? Once again, it seems all new buildings constructed in the past 30 years want electric heat or heat pumps. Nobody seems to want hydronic heating in their new building!! Any thoughts appreciated!

Thanks.

[supertek65]

Cost cost cost.

But when gas and oil were cheap and comfort was more important than efficiency.
There were dual duct systems!
Heat was sized to be used with cooling in a dual duct application as are 100% of my accounts.

Now single duct vav.
Series and parallel fan powered boxes with strip heat on the perimeter! Basically to wash the windows!

Now they are using lighting with way less watts/btus.

The lack of heat from lighting decreases cooling load but
Increases the heating requirements.

Nothing is free!

[MHall]

Lotta new schools around here. Chillers & boilers. So maybe that's how the big boiler makers last. Or churches. We have a new 2M Fulton Pulse and a bunch of Carrier splits with air handlers in our renovated building.

In a big city, there's often district heat. Indy has one of the largest in the country. Most older buildings don't have boilers and get their steam from the district plant. About all new buildings in reach of their lines get their steam and chilled water from them. Many older buildings that lose chillers also tap into the lines.

If Install cost is such a factor for the change from boilers to heat strips, did they simpley have more disposable income to spend on eqipment back then??

Baldlonnie; You say that many schools in your area have chillers and boilers. How old are these schools?? I would quess that any school with HWH Boilers would be built in the 1970s or before.

Thanks for the comments!

[BaldLoonie]

From what I see, schools built today locally have boiler stacks on their mechanical rooms, usually have air cooled chillers for cooling. In schools, compared to offices, most rooms have lots of windows and there tend not to be the interior only rooms so there is more heating demand. Offices often have a large interior area where heating would never be needed.

Friend of mine once worked in the Hennepin Country crime lab. They have 5 air handlers in a penthouse, an air cooled chiller on the roof, connection to district chilled water and use district steam for heat. Course it gets colder up there!

[Pete838]

From what I see, schools built today locally have boiler stacks on their mechanical rooms, usually have air cooled chillers for cooling. In schools, compared to offices, most rooms have lots of windows and there tend not to be the interior only rooms so there is more heating demand. Offices often have a large interior area where heating would never be needed.

Friend of mine once worked in the Hennepin Country crime lab. They have 5 air handlers in a penthouse, an air cooled chiller on the roof, connection to district chilled water and use district steam for heat. Course it gets colder up there!

I think this highlights the difference between structures built for lease, like office towers, and those that are purpose built and owner occupied.

[MHall]

Another question that this thread has lead me to ask is; "Why don't any new office towers use district steam (such as Con Edison) for their heating needs??Instead they want to use heat strips.

With district steam space is not an issue, and their is no boiler to maintain. You also do not require an engineer on site to watch boiler/steam operations.

I simply do not see why district steam is also being phased out in new construction? Is electric heat ALWAYS the standard when constructing a new building such as a office tower??Thanks for your imput!