Jeff Burton <jeff@eburton.com> 

11/18/2005 02:07 PM

	

To

Kendra Schlueter/DC/USEPA/US@EPA

cc

Subject

Re: Ventilation questions









-- From D. Jeff Burton, PE, CIH    http://www.eburton.com -- tel
801-298-8996 -- fax 801-298-9098      ----> Check out VENT 2006! =   
http://www.aiha.org/aihce06/vent2006.htm

Hi, Kendra.

My responses are shown at ******

(1) The first question pertains to the number of fume hoods required per

firm, which is driven by the firm¹s annual usage of an aerosol cleaner.

The first question can best be asked with a scenario: 

     A firm has 16 employees which use a particular aerosol solvent

in rework type applications in NAICS code 334, Computer and Electronic

Product Mfg.  If 16 employees are doing the same operation in several

areas of the plant‹how many fume hoods would be necessary?  Would all
16

employees share 1 fume hood?  As a firm¹s size increases, at what point

would two fume hoods be necessary 32 employees, 64 employees?

*******The answer depends on several factors: toxicity and hazard rating
of the solvent; how the solvent is used; hours of "rework" per day and
per worker; work rate; how many are doing "rework" at any one time, the
size or dimensions of the "rework" material or part, and so forth.

As a minimum, we expect at least two feet of hood face per person. So
two workers could work in a five-foot hood, for example, if all the
"rework" would fit in the hood. 

More normally it is one person per hood. So if four people have to work
simultaneously with relatively small parts, we would normally recommend
four 4-foot hoods, for example.

(2) What is your best cost estimate of an industrial fume hood used in

the aforementioned application and industry?

As a general rule, we figure it costs $5,000 to $10,000 to properly
design and install a lab hood plus it's air cleaner, fan, ductwork,
stack, makeup air unit, controls, etc. If more than one hood is
installed at the same time, the costs will be lower. But again, costs
depend on many factors: the hood type and quality, ductwork materials
and fittings, design effort, control types and quality, air cleaning
requirements, permit requirements, geographical location, commissioning
costs, and so forth.

In most cases, it is the long-term operating costs that become
significant, not the initial costs. These two costs have to be
considered together. A cheap initial installation might be more
"expensive" in the long-run than a quality initial installation that has
higher capital costs but lower O&M costs.

(3)  What is your best cost estimate to train one employee on such fume

hoods?

A good 1-day training course should be sufficient in most cases: about
$2500 if I did the training. If you have more than one employee being
trained at the same time, then the costs will be lower, of course.
Again, many variables must be considered: Working with ethyl alcohol in
a hood is much different than working with plutonium and training
requirements will differ as well. And you must consider hood type,
materials to be used, educational level of worker, language
considerations (speaks Spanish?), and so forth.

Best wishes! -- Jeff

