What's That Smell?

[NJEyeGuy]

My store is in the midst of renovating a new location where we will be adding a lab. I have been working in labs for years but I have never been asked for my opinion on this- The optometrist would like to ensure that smells from lens finishing not distract or deter customers, so I have been asked to offer advice on how to prevent this... any thoughts? My first thoughts are to include a HEPA filtration system with 1 or 2 intakes positioned in the lab and this would also improve air quality overall. Thanks in advance for the help!

[Chris Ryser]

First of all you need collection hoods over the fume emitting sources as bevel edger and tinting units. Blow the air outside if possible. Hepa system is then only needed if you can not do that.

[MikeAurelius]

As Chris said...but I'll expand on that a bit.

I'm also a glassworker and we deal quite a bit with heat AND fumes/vapors from working with molten glass. I've written several articles on ventilation that you can find here: http://mikeaurelius.wordpress.com/ventilation-primer/

The ventilation primer has 3 parts, the first an overview of local ventilation; the 2nd, an overview of the math required to "do it yourself"; and 3rd, some sample hood designs.

Basically, you need a fresh air source (called makeup air) to replace the exhausted air.
Next, you need a hood to collect the fumes and a fan and ducting system to blow them outside.

Ducting is usually best when done through a side wall -- roofs are incredibly expensive to duct through.

A properly designed and installed system will result in zero fume odors in the store.

[David_Garza]

Man, I thought this was a thread about Lynyrd Skynyrd!!!!

[NJEyeGuy]

LMAO @ Skynyrd

Is there a good pre-fab hood set up or a good quality hood company you can recommend?

[Lee Prewitt]

AirMax filtration unit from AIT has been very successful in eliminating those pesky smells...http://www.aitindustries.com/cscart/...on-system.html

[MikeAurelius]

LMAO @ Skynyrd

Is there a good pre-fab hood set up or a good quality hood company you can recommend?

The biggest problem with pre-fabs is that they are hideously expensive to ship, you are paying for cubage instead of weight. I've always recommended that you contact a local HVAC company and ask them to build a hood for you.

I'd stay away from the "hood-less" aka "duct only" type of venting systems. These systems collect only fumes in a direct line with the duct and are not designed to pull fumes from a wide area.

Typically speaking, you want a hood that's going to cover the source of the fumes and about 6 additional inches all the way around. You are also going to want it mounted directly over the unit, with low enough that it captures the fumes, but high enough that the operator can work under the hood. For example, a dye tank on a bench, you are going to want to have the hood no higher than about 3 feet above the tank. Any higher than that and you risk having fumes waft into the general work area, or you are going to have to go with more than 125 CFM per square foot of hood area in order to pull the fumes up into the hood, which will then require more fresh air intake.

I'm also not a fan (heh...pun intended) of recycling air that's filtered through an activated-carbon filter. The whole point is to get the fumes out of the room. Exhaust them outside. You will pay approximately the same amount of money for an exhaust system as you will for a recycler, and you will have much fresher air. Recyclers only remove so much in the way of smells, and then they get over powered. Additionally, the activated carbon filters do "wear out" and have to be replaced, so your on-going expenses are going to be much higher with a recycling system instead of an exhaust system.