Amico NFPA Triplex RVL Modular Stack Mount - Manual (Page 3)

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7.1 How to Use This Section
The following section is organized such that the medical vacuum system for a project may be developed and
executed in a logical and simple progression. Examples are given whenever possible.
The basic milestones in designing the medical vacuum system are as follows:
• Definitions – Definitions are provided as a general guide that contains terminologies which may be
frequently utilized within the Medical Vacuum Systems section. These terms may also be helpful in both
understanding & identifying the appropriate medical vacuum system for your medical facility.
• Design – General outline pertaining to procedural involvement in designing your Medical Vacuum Systems.
• Sizing and selecting the Medical Vacuum System – How to calculate the Peak Calculated Load (PCL)
requirements for the medical facility.
• Installation – Steps to building your medical vacuum systems.
7.2 Introduction
Medical Vacuum Systems
Medical vacuum in comparison to other medical gas source systems is quite straightforward. The most intricate
part of the course comes in the selection of the technology to be used because there exists many competing
technologies, each of which has their own appeal and it must be said, their own downfall. NFPA standards have
relatively few requirements of which are readily met, thus the decision becomes a balancing of the clients’ concerns
for risk, initial cost vs. life cycle cost and maintenance requirements.
Engineers use the term “vacuum”, but clinicians refer to them as “suction” and if you have had the opportunity to
speak with the clinicians, you’ll find the terminology subtlety different. In addition, although the average clinician
cannot articulate it, their major concern is flow. It is quite common to have a maintenance worker, having been
called in because of “poor suction”, plug in a vacuum gauge and quite accurately tell the complaining nurse “you got
all I got”. He’s right in terms of vacuum level, but the nurse is really referring to the fact that there is a lack of flow.
If we are to design a successful blueprint, we must grapple this problem all the way through the system. Giving a
higher ultimate vacuum may be helpful, but it rarely solves the flow problem because only fat pipes are capable of
achieving that. Seeking a high vacuum level may actually squander our client’s financial resources yet provide no
solution to their real problem.
The methods for sizing vacuum sources are always a surprise to new engineer because there are so many and
because the most commonly used are so poorly documented. The CGA P-2.1 has been withdrawn by its publisher,
the Compressed Gas Association. It was essentially unchanged since the 1970’s but there is almost nothing but the
patina of age to authenticate the numbers it contains. The method we will be using in this design guide follows the
latest edition of The National Fire Protection Association Standard (NFPA).
The NFPA method was removed from the NFPA 99 because it was considered out of date. Fortunately, it at least has
a research history. We continue to use these two in the US because we have used them for so long we understand
their restrictions, and we know from experience that they do work.
The HTM method is published in the HTM 2022 standard, and is the method used in the U.K. We have included it
here as an additional method for comparison.
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