Page 404 - Industrial Ventilation Design Guidebook

6. i DEFINITIONS AND CONNECTION TO DESIGN METHODOLOGY 359

In most cases the main steps in defining target levels relating to industrial
ventilation are as follows.

Step I: Musts
Ascertain the requirements of laws, regulations, and standards related to
legislation, processes, and equipment, and compare them with customer
needs. Of course, before this step, needs of the end user—for example, eco-
nomical boundary conditions—are identified. At this stage the tentative target
levels have also been selected.
Step 2: Needs
Ascertain nonbinding standards, human comfort standards, guidelines,
codes of practice, and custom needs.
Step 3; Target Levels
Define the target levels based on musts and needs.
Step 4: Design Conditions
Suggest and confirm with customer the outdoor or process conditions
within which the target levels must be met (e.g., absolute maximum tempera-
ture versus 95 percentile temperature).
Step 5: Reliability
Find out the customer reliability requirements of the process. Define and
obtain the customer's acceptance of the needs for ventilation system reliability
(e.g., what is the allowed break-off time).

6.1.3 Combination of Target Levels and Design Methodology
The combination of target levels and design methodology is of vital impor-
tance. One of the main items in the INVENT program in Finland over the
years 1991-1996 was the development and utilization of these concepts in the
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ventilation of industrial premises. Together, these two concepts form the basis
for industrial ventilation systems.
The target level concept was introduced and developed by the Association of
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Finnish Manufacturers of Air Handling Equipment (AFMAHE) in 1985. ' In-
door climate target levels have been utilized in the ventilation of public buildings,
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apartments, and offices for years. " The Finnish Institute of Occupational Health
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began to develop the concept for industrial ventilation in 1991. > The target level
procedure for industrial air quality is described in more detail in Section 6.4.
In the design methodology, the whole life cycle of the process must be
considered. The life cycle of the process can be divided into four parts: design,
construction, operation, and end of the process. Each consists of different
tasks. The design methodology process can be described as follows:
Given Data

• Collect and identify data that do not change during the design process,
such as outdoor conditions.