Is an Ammonia Refrigeration Evaporative Condenser a Permit- Required Confined Space (PRCS)?

Source Article: Condenser by IIAR

By Bryan Haywood

Carlson & Stewart Refrigeration (CSR) has been asked this question many times in the past and we have found that many people have their own interpretations.  In larger systems we have stressed people to follow their PSM guidance.

This article will explore the questions so many have regarding their evaporative condensers and OSHA’s Permit Required Confined Space standard(s) (29 CFR 1910.146 and 29 CFR 1926.1201 – .1213).

We will look at the two most com- mon models/designs:

  1. Forced Draft (fans are vertical and on the bottom section)
  2. Induced Draft (fans are horizontal and on the top section)

Although both condenser designs will share an atmosphere between the top and bottom sections, depending on the model at your facility, the top and bottom sections most likely will need separate evaluations done because the physical hazards in these sections and the results may be different. For example, the lower section of an induced draft condenser may only be a “confined space”, where the upper fan maintenance section is without a doubt a “permit- required confined space”, because of the proximity to fan blades and power transmission devices. This is important to point out, because most condensers will in fact have two (2) spaces within the unit; each one needing its own evaluation and possibly its own labeling based on the outcome of the evaluation(s).

First things first, what makes an evaporative condenser a “confined space” (CS)?

In the USA, we use OSHA’s criteria that any space that meets ALL THREE (3) of the following is defined as a Confined Space:

  1. Is large enough and so configured that an employee can bodily enter and perform assigned work; AND
  2. Has limited or restricted means for entry or exit; AND
  3. Is not designed for continuous employee occupancy.

So, let’s ask ourselves:

Are condenser’s “large enough and so configured that an employee can bodily enter and perform assigned work”?

YES. Workers “bodily enter” (i.e. fully enter) this equipment for maintenance activities and once inside, have no problems moving around to do their assigned tasks.

In fact, many manufacturers are making their units easier to bodily enter and perform assigned work by making their entry portals larger. (More on these “larger openings” later)

Most forced- draft models have entry portals on both ends of the lower fan section, but once through the entry portal (i.e. manway) these models are quite “roomy” regarding confined space size standards.

In induced draft models that have top fans, the fan access area can be a tight squeeze to work in, but the space is actually provided by the manufacturer to bodily enter and perform assigned work on the fan and its power transmission devices. So clearly these spaces are large enough and so configured that an employee can bodily enter and perform assigned work.

Do condensers have “limited or restricted means for entry or exit”?

YES. Even with the two (or more) openings, ALL the entry/exit portals on all models I have ever seen pose a LIMITED OR RESTRICTED means of entry or exit! I like to say…

“Any opening that we have to slide/ slither/crawl/climb/contort through is a “limited means of entry or egress” REGARDLESS of how many of these types of openings there are to enter or exit the space”.

We can literally have dozens of openings of which we can slide/slither/crawl/climb/contort through and the number of openings means absolutely nothing – it is the size of those openings that matters.

Since this “limited or restricted means for entry or exit” characteristic seems to be causing a lot of confusion due to some marketing/sales literature from some manufacturers, I thought it would be prudent to share OSHA’s official position (since 1995) on how the phrase “limited or restricted means for entry or exit” is defined within the agency’s OSHA Instruction CPL 2.100:

A space has limited or restricted means of entry or exit if an entrant’s ability to escape in an emergency would be hindered. The dimensions of a door and its location are factors in determining whether an entrant can easily escape; however, the presence of a door does not in and of itself mean that the space is not a confined space. For example, a space such as a bag house or crawl space that has a door leading into it, but also has pipes, conduits,  ducts, or equipment or materials that an employee would be required to crawl over or under or squeeze around

in order to escape, has limited or restricted means of exit. A piece of equipment with an access door, such as a conveyor feed, a drying oven, or a paint spray enclosure, will also be considered to have restricted means of entry or exit if an employee has to crawl to gain access to his or her intended work location. Similarly, an access door or portal which is too small to allow an employee to walk upright and unimpeded through it will be considered to restrict an employee’s ability to escape.

OSHA published a technical amendment to the preamble in Federal Register / Vol. 59, No. 213 / Friday, November 4, 1994, page 55208. (emphasis by me – NOT by OSHA)

Basically, for an entry/exit portal to NOT limit or restrict the means for entry or exit, the portal would need to be a FULL-SIZE door so the entrant could literally walk into the space as if he/she were walking into an office. And even with this full size door, the space may still pose “limited or restricted means for entry or exit” due to the configuration of the space and equipment, such as piping, conveyors, and baffles, within the space.

So, with all that said, most evaporative condensers will have limited or restricted means for entry or exit.  Are condensers “designed for continuous employee occupancy”?

NO. Evaporative Condensers are designed to have water cascading down over refrigerant coils and have fan blades moving large volumes of air thru the unit. There is NO WAY any rational person can argue this space was “designed for continuous employee occupancy”. Offices, lunchrooms, training rooms, process production rooms and etc. are “designed for continuous employee occupancy” – NOT evaporative condensers.

We cannot confuse “maintenance access portals” provided by a manufacturer with the phrase “designed for continuous employee occupancy “. Just because a manufacturer provides a means to enter their condenser (as they all do), this in no way alluding that the space is “designed for continuous employee occupancy”.

This debate regarding condensers is quite easy, because most manufacturers have placed DANGER signs at their entry portals telling the entrant that hazards are present behind the entry portal cover. If the space be- hind the cover was in fact “designed for continuous employee occupancy” there would be no hazards within the space and no need to place DANGER/CAU- TION/WARNING signs at the portal(s).

So, we have a space, an evaporative con- denser, that:

  1. is NOT designed for continuous employee occupancy, AND
  2. has limited or restricted means for entry or exit, AND
  3. is large enough and so configured that an employee can bodily enter and perform assigned work

The results of our assessment tell us our evaporative condenser is a CONFINED SPACE.

But strictly in the terms of OSHA compliance, 29 CFR 1910.146 and 1926.1201-.1213 do NOT apply to spaces that are determined to be merely a “confined space”. For these OSHA standards to apply to the space, the space must have a permit-required con- fined space (PRCS) hazard.

OSHA defines a PRCS as a “confined space” that has at least one (1) or more of the following hazard(s):

Contains or has a potential to contain a hazardous atmosphere; OR

Contains a material that has the potential for engulfing an entrant; OR

Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; OR

Contains any other recognized serious safety or health hazard.

For the sake of time and space, I will not break down each of these four (4) categories of PRCS hazards because OSHA has done a nice job within both standards AND because we really only need to discuss two (2) of the hazard categories. Leaving out, for now, the discussion regarding the ammonia  in the coils during entry, I do NOT believe condensers have: a material that has the potential for engulfing an entrant, NOR do they have an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section.

Please understand that I have never managed treated or untreated condenser water cascading down into a basin that is knee-deep as an “engulfment hazard”. I keep hearing arguments put forth that the condenser water is “treated” with some hazardous chemicals and therefore “treated water” should be considered a “hazard”. Folks, I will never tell anyone who feels like something is a hazard to not respect their feelings; however, if we truly believe our “treated water” is indeed a “hazardous chemical/material” we will need to take the following steps just to meet OSHA minimum safety stan- dards regarding hazardous materials:

  • obtain or develop a SDS for this “treated water”,
  • ensure our condenser basins and feed tanks are properly labeled with ap- propriate hazard labels to reflect the hazard(s) of the “treated water”, and
  • label our “treated water” lines/pip- ing per ASME A13.1, Scheme for the Identification of Piping Systems

I have yet to find anyone who has claimed their “treated water” is hazardous and has taken any of these steps mentioned above to properly manage their “treated water” as a hazardous chemical/material as spelled out in 29 CFR 1910.1200. But I digress – feel free to manage your “treated water” as a “hazard” but it will NOT be an “engulfment hazard” in the vast majority of condensers due to the design, size, and configuration of most condenser basins.

HOWEVER, condensers do contain a “recognized serious safety or health hazard” because once we have entered, either the upper fan section on the induced draft models or the lower fan section on the forced draft models, we are exposed to UNGUARDED FAN BLADES and POWER TRANSMISSION DEVICE(s). These mechanical hazards make these spaces within the condenser a PRCS.

CSR would be happy to discuss this topic with you more in the future as you may be presented with the question.

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