Code Quest.: Chillers and Boiler in Same Room?
Code Quest.: Chillers and Boiler in Same Room?
(OP)
Is there a code that prevents chillers and boilers from being located in the same mechanical room? if so, does anyone know when this went into effect? Is there any boiler or chiller size that triggers the code? And, why is there such a code, if it exists. Thanks!





RE: Code Quest.: Chillers and Boiler in Same Room?
KRB
RE: Code Quest.: Chillers and Boiler in Same Room?
RE: Code Quest.: Chillers and Boiler in Same Room?
Modern flame safeties should prevent this, and also your chiller's rupture disk should be piped outdoors, so it's more of a thoughtful thing than a real need...
Best to all,
Old Dave
RE: Code Quest.: Chillers and Boiler in Same Room?
I know of a number of jobs where the fridge pipes have been enclosed when passing through a boiler house.
Alternatively, if you really have to put refrigerants in a boiler house, then perhaps some form of emergency ventilation might be appropriate.
My initial feeling however would be to keep 'em separate and avoid the risk in the first place.
Friar Tuck of Sherwood
RE: Code Quest.: Chillers and Boiler in Same Room?
As to any code requirements, you should check with your local jurisdiction. ASHRAE 15-2001 does not prohibit it, local/state code might.
Most federal agency instructions do prohibit it when designing themself a new chiller/boiler plant....Same for some industrial owners....It all depends on their own written instructions and in many cases, that of their insurance carrier.
A large hospital here in my town just commissioned a new combined plant and had no problem passing state/city code.
Keep in mind that if the boiler(s) and chiller(s) are located together, the plant must meet ASHRAE 15-2001 concerning proper leak detect and emergency ventilation requirements....and the ventilation provided must be in addition to that required for boiler combustion air.
RE: Code Quest.: Chillers and Boiler in Same Room?
Small modular chillers can be installed in the same room as boilers, but I believe you must still have a refrigerant detection system that will shut down the flame producing equipment when a leak is detected.
Some of the requirements of separation may also be avoided by having the appropriate Power Engineers on site during occupancy. (Power Engineers Act up here)
RE: Code Quest.: Chillers and Boiler in Same Room?
In installations where it is not possible to partition off the boilers from the chillers consider providing an interlock w/ the refrigerant leak monitor system, to shut off the boilers when refrigerant is detected. Hopefully the refrigerant leak can be purged out before the facility have any problems from lack of heat. This procedure may not be allowed in hospitals where a redundant boiler is required and also where steam sterilization processes or other process heating are in used.
RE: Code Quest.: Chillers and Boiler in Same Room?
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 combustionprocess in the event of refrigerant leakage.
KRB
RE: Code Quest.: Chillers and Boiler in Same Room?
BS 4434:- Safety aspects in the design, construction and installation of refrigerating appliances and systems (No longer current but cited in the Building Regulations)
The pertinent clauses are;
3.2 Machinery Rooms serve for accommodating refrigeration machinery but need not serve exclusively for this machinery. It is however recommended that boilers and other naked flame devices should be excluded.
H.3.2
The installer or manufacturer is required by the Health and Safety at Work Act to draw the attention of the user to........the extra danger to health from decomposition products caused by smoking or naked flames in the presence of certain refrigerants.
This document is 15 years old and refrigerants have changed a lot in that time. There's probably other BSs with similar safety clauses.
RE: Code Quest.: Chillers and Boiler in Same Room?
steelabella asked for the reason for the code(s) and although newer refrigerants are somewhat safer, phosgene (mustard gas) formation is a real concern when traditional refrigerants (say R11, R- 12, R-113, R- 114) decompose.
Refrigerants and flame don't mix.
cheers,
John
RE: Code Quest.: Chillers and Boiler in Same Room?
ASHRAE 15 appears to be attempting to prevent the formation of decomposition products by reducing the likelihood that refrigerants and flame will share the same space at the same time.
RE: Code Quest.: Chillers and Boiler in Same Room?
RE: Code Quest.: Chillers and Boiler in Same Room?