On Sun, 01 Jan 2012 16:12:25 -0600, Vic Smith
wrote:




You guys are talking apples and oranges.
The boiler Mike linked to is designed to heat one building.
It *is* "decentralized."
Industrial and municipal steam systems fit the "centralized" category.

Depends on how you use the word. This is a mini-decentralization. What
Harry is talking about is having one central boiler to do the entire
building, rather than a bunch of smaller, efficient, water heating
units, one per apartment. We really are talking about the same thing
and one of my projects this year is to look into doing exactly that in
our building at work.

There is a section of our building that is about 100 years old. It
has sprinklers and must be kept above freezing. Two spaces are rented
out. The rest of that building probably never will be rented, but
still must be heated.

So far, I've broken off the two tenant spaces and converted them to
gas fired water. A portion of the "new" building where our offices are
was also heated by the steam boiler. They were taken off and put on
to another existing water boiler.

The unused portions of the building just have to be kept from
freezing. Part is used for storage, the rest is empty and not
practical to rent. The steam boiler runs either two hours a day or
four hours, depending on outside temperature. It has never needed
more than two 2 hour periods even on the coldest days.

If we wanted to keep the building at say, 68 degrees for occupied
space, it would be a no-brainer. With minimal running, the payback
for the project will be much longer. It is not just buying the
boilers, it is also the piping, partitioning, venting, etc. that must
be done.



I might question using steam depending on the size of the building.
Could be a case of "that's how we always did it."
Then again the cost of converting to hot water might not work.
If it's one pipe steam, probably not.
Hot water needs inlet and outlet on the radiators.
Steam radiators are usually smaller because steam is hotter.
Blah blah.
You need an expert to scope that out, and that's not me.

Exactly. Steam was installed in our building because, at the time it
was the most practical. From the boiler in the basement, steam has to
move up to three floors plus an attic. Before changes, it had to move
horizontally about 200 feet and the up 10 and down 10 for that section
of the building. That was already changed over.

We bought this building in 2001 and moved production to it in 2007.
The building we have is 180,000 square feet and has every type of
heating known to man as it was built from 1890 to 1975 and we started
refurbing in 2007. Gas fired steam, two gas fired water heaters. 2
oil fired hot air units, 3 gas fired rooftop heaters (installed 2008).
electric baseboard, 5 gas fired unit heaters. The rooftop units
replaced some infrared heaters that we could not have with our
process.

In addition, we have two 125 hp gas fired process boilers that operate
at 110 psi. There is enough heat from the machines that the
production area needs no added heat when operating.