Furnace / Boiler Room

[Mech]

2009 IBC / IMC

Where does the code dictate when an enclosed room is required for a furnace or a boiler? I know IBC Table 508.2.5 says a furnace room where any piece of equipment is over 400,000 BTU/hr input requires a 1-hr separation or automatic fire suppression. But I thought somewhere in either the 2003 or 2006 codes, it specifically stated when a furnace or boiler room is required.

Thanks.

 

[Glennman CBO]

A room is required when it would need to have a rated enclosure.

I'm not sure that you can require a room where there is no requirement for a rated enclosure. I don't recall anything that required just a room.

It seems like they would want a room. Can't you just say "get a room"? (sorry)

There may be something of an energy issue if there is not a room. It seems like it would be pumping alot of heat into the other portions of the building if the area is not enclosed in any way. What about something along the lines of required ventilation for the room? It may be that if a certain amount of ventilation is required due to the boilers, a room may be required to contain the ventilation area. What fires the boilers?

Just shooting from the hip.

 

[Mech]

It seems like they would want a room. Can't you just say "get a room"? (sorry)

Ughh. That was bad. I laughed, but it was still bad.

The owner is replacing an oil fired heating apparatus with (2) oil fired units. The existing units are hung from the roof steel; the new units will be floor mounted on a new equipment platform. I believe the new units are 500,000 Btu/hr each, which means they need a room.

 

[mtlogcabin]

Rooms with boilers where the largest piece of equipment is over 15 psi and 10 horsepower needs to be in a 1 hour room or sprinklered, The 400,000 BTU's is for requiring 2 exits from a room more than 500 sq ft with a boiler, incinerator or furnance that size.

I am not an expert on boilers by any means but I do know that 15 psi and 10 horsepower does not automatically equate to 400,000 BTU's

Depending on the size of the room a boiler may need to be listed for such an installation.

2006 IMC 303.5 Indoor locations.

Fuel-fired furnaces and boilers installed in closets and alcoves shall be listed for such installation. For purposes of this section, a closet or alcove shall be defined as a room or space having a volume less than 12 times the total volume of fuel-fired appliances other than boilers and less than 16 times the total volume of boilers. Room volume shall be computed using the gross floor area and the actual ceiling height up to a maximum computation height of 8 feet (2438 mm).

 

[mtlogcabin]

FYI

BOILER HORSEPOWER EXPLAINED:

Prior to 1876 Boiler Horsepower was based upon the heating area of a boiler with every 10 square foot of heating surface equaling 1 boiler horsepower. This would mean that a boiler with 200 square feet of heating surface would be rated at 20 boiler horsepower. Not a very exact way to measure the output of a boiler to say the least, especially given the different designs and efficiencies of boilers available.

All this changed at the 1876 Centennial Exhibition held in Philadelphia, PA. There judges decided to use “developed horsepower” which they defined as the ability to turn 30 pounds of 100 degree F feedwater per hour into steam at 70 psi. In 1884, ASME defined Boiler Horsepower as the amount of power required to convert 34.5 pounds of water per hour from feedwater at 212 degree F to dry, saturated steam at the same temperature. Today 1 boiler horsepower is equal to 33,475 Btu/Hour which is the amount of energy required to evaporate 34.5 pounds of water at 212 degree F in one hour.

So a 10 horsepower boiler (33, 500 btu) and operating at over 15 psi would require a 1-hour room. A boiler has to meet both conditions before the protection is required.

 

[Dr. J]

The equipment will be in a room, there happens to be more than just heating appliances in that room, but it is still in a room. As long as the installation complies with the equipment location restrictions of 303.3, and the return air restrictions of 918.6, there is nothing that requires fuel fired equipment to be in a dedicated room. It's just that any room that does have any fuel fired equipment over 400,000 btu/h is required to either be sprinklered or separated from everything else. The existing situation had a single 1 million btu/h unit in that room, right?

Once presented with the requirement of rating an existing large room that happens to have large fuel fired equipment in it, the owner may CHOOSE to construct a new dedicated room, but is not required to.