chiller + boilers in same equip. room
chiller + boilers in same equip. room
(OP)
Anybody know what code issues I might run into by locating a 50 ton chiller in same room as two one-million btuh boilers? Someone seems to think there may be issues and one person has eluded to ASHRAE standard 15. This is in Indiana, USA. I am looking at a split type chiller system so actually only the evaporator barrel would be in the equipment room.





RE: chiller + boilers in same equip. room
Friar Tuck of Sherwood
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
The problem with phosgene gas was from chlorine based refrigerant, primarily R-11.
Ken
TXiceman
www.rae-corp.com
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
After checking the ASHRAE 15 code a little more in depth, I found the following:
8.11.6 No open flames that use combustion air from the
machinery room shall be installed where any refrigerant is
used. Combustion equipment shall not be installed in the
same machinery room with refrigerant-containing equipment
except under one of the following conditions:
(a) combustion air is ducted from outside the machinery
room and sealed in such a manner as to prevent any
refrigerant leakage from entering the combustion
chamber, or
(b) a refrigerant detector, conforming to 8.11.2.1, is
employed to automatically shut down the combustion process in the event of refrigerant leakage.
KRB
I would suggest that you get a current copy of ASHRAE 15 and review it for your application, and consult your local codes on the issue. Sections 8.11 and 8.12 are both applicable.
KRB
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
Chiller rooms are under negative pressure
Boiler rooms ar under neutral to positive pressure
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
Here are the three refrigerants most used today -
DuPont's MSDS on R-123:
"Decomposition products are hazardous. This material can be decomposed by high temperatures (open flames, glowing metal surfaces, etc.) forming hydrochloric and hydrofluoric acids, and possibly carbonyl halides."
DuPont's MSDS on R-134a:
"Decomposition products are hazardous. This material can be decomposed by high temperatures (open flames, glowing metal surfaces, etc.) forming hydrofluoric acid and possibly carbonyl fluoride."
DuPont's MSDS onn R-22:
"Decomposition products are hazardous. "FREON" 22 can be
decomposed by high temperatures (open flames, glowing metal
surfaces, etc.) forming hydrochloric and hydrofluoric acids,
and possibly carbonyl halides."
Note that some carbonyl halides form phosgene gas.
There is no excuse for not segragating boilers from chillers with fire-rated walls. As can be seen, even hot metal is enough to cause a problem. I cannot imagine "some of the top engineering firms in the country" allowing this to take place in high occupancy environments. Any Fire Department with which I'm familiar would dismiss the construction out-of-hand.
Refrigerant detectors do not stop leaks or exposure to combustion, neither do exhaust fans. The detector only warns of the event after it's occurred, and exhaust fans can only limit the breach once a leak has started. A proper design does not allow the potential for exposure in the first place.
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
RE: chiller + boilers in same equip. room
2. Lithium Bromide "refrigerant" is a dry powder in an aqueous solution used for heat-driven, absorption chillers. It is not a CFC, HCFC, HFC, or even ammonia, all of which are refrigerant gases that use compression to input refrigeration cycle work. It is apples and oranges on a grand scale with respect to the conversation.
3. Absorption chillers are heat-input devices, and are very similar to boilers. In fact, a direct, gas-fired absorption chiller has virtually the same NFPA code requirements, and may actually double as a hot-water boiler.
4. The applicable codes regarding facility design and segregating combustion fuel sources and combustion equipment can be found in NFPA 85, NFPA 101, ASHRAE Std 15, and many various national, international, regional, and local codes.
You will find that your direct-fired, combustion heat equipment is separated from the rest of your building(s) with significant fire ratings. Also, the lithium-bromide absorption refrigerant solution and cycle is much older than many of the refrigerant gases mentioned.
I would state some pointed things at your opinions of codes vs. safety, but that's too much of a digression at this point. Suffice to say that code adherence is a minimum threshold, and does not completely warrant the Engineer (or owner) from liability.
Apology accepted at your not mentioning that you used heat-driven chillers the first time (and other stuff). Not to put too fine a point on it, though, but that's what "integrated" your heat and chiller plants - by definition.
RE: chiller + boilers in same equip. room
The question posed in the first post should not be allowed. Even the evaporator barrel has the potential for leaks or rupture. Further, depending on the refrigerant, there may be a chance of a vacuum potential with a leak. It is also prohibited in that case - since it may draw in combustible or explosive mixtures from the boiler room.
Many boiler installations use fuel oil as a backup. The segragation of fuel oil spaces is a familiar requirement. There are many other codes that cover these issues. NFPA 54 and 31 deal with combustion fuels, and BOCA and SBCCI also deal with combustion and ventilation air. There are others, as well.
Smaller packaged steam or hot water boilers may have greater flexibility, but I would note that even residential hot water boilers have minimum requirements for fire-rated enclosures.
It is correct to suggest that cost and space are the issue: because fuel and combustion devices require a greater investment in facility costs. Economically, the choice is reducing that area and that cost, not increasing it by co-locating other items that require additional protection from the pre-existing equipment.
Ultimately, it is up to the Engineer to recognize these dangers. No code can instruct on the knowledge of the equipment design, its operating materials, or which codes apply.
RE: chiller + boilers in same equip. room
That doesn't make good engineering practice in my book!
RE: chiller + boilers in same equip. room