All about the static

[choice]

I have a customer (Hair Salon) calling me and complaining about a high amount of static electricity in there space. They stated that their customers are complaining and the hair on their arms are sticking straight up, also the hair on the floor surface is sticking up even, etc. I am going to see for myself and run a sling to see what the RH is really doing.

This is a common supply plenum from Air Handlers that serve the whole building and I know there not any static problems in the rest of the building. This is Seattle which in general has high humidity unless it is freezing and clear. It is a fairly new space and the outside humidity is at 80 percent. Supply air temperature is 55 degrees typically here and is reheated with electric heat. It is a fairly new built out space.

[dlove]

I have a customer (Hair Salon) calling me and complaining about a high amount of static electricity in there space. They stated that their customers are complaining and the hair on their arms are sticking straight up, also the hair on the floor surface is sticking up even, etc. I am going to see for myself and run a sling to see what the RH is really doing.

This is a common supply plenum from Air Handlers that serve the whole building and I know there not any static problems in the rest of the building. This is Seattle which in general has high humidity unless it is freezing and clear. It is a fairly new space and the outside humidity is at 80 percent. Supply air temperature is 55 degrees typically here and is reheated with electric heat. It is a fairly new built out space.

humidity and temp is a factor but, It may be the flooring. This is the standard for floor concerned with static issues. ANSI/ESD S 20.20-2007. http://www.esda.org/s2020.html Have them check what type of flooring material they used. Is it VCT, tile, paint?

not an expert on this, i have worked on many build outs with server rooms that are spec'd with Static Dissipative flooring. one suggestion you can make is have someone like a cleaning company or a flooring company apply a finish that helps with static, they make a Static Dissipative Spray Buff and floor finishes that helps static issues.

[jburchstead]

Constant temp. w/ reheat systems are great for controlling humidity on the high end but can push your RH low during the winter months, and oh, BTW, the power companies love these designs. A few things you might want to think about if you haven't thought about them already,

1- When you do your sling, get some readings in other spaces relative to down stream of the AH and in the NE & SW corner of the building.

2- Interview the tenant to see if this a continual or intermittent problem.

3- Note the ambient temp. in your client's space (hairdryers?)

Let us know what you find.

[choice]

Constant temp. w/ reheat systems are great for controlling humidity on the high end but can push your RH low during the winter months, and oh, BTW, the power companies love these designs. A few things you might want to think about if you haven't thought about them already,

1- When you do your sling, get some readings in other spaces relative to down stream of the AH and in the NE & SW corner of the building.

2- Interview the tenant to see if this a continual or intermittent problem.

3- Note the ambient temp. in your client's space (hairdryers?)

Let us know what you find.

You are definitely right on low RH in the cold. The last two days have been snowing and sunny. Today seems to be a stable temperature, so this is what I have:

1. RH readings
The Space West side: space is 52 WB and 70 DB which is 38% Taken 4 times.
Outside East side of buildig: 42 WB and 48 DB which is 51%
Inside of building South end: 55 WB 71 DB at 32%
Inside of building North End is: 56 WB & 70 at 40%
Outside East side of building is 43 and 49 at61% (More clouds must have came in) We are right on the sound.
Outside of building North end is: 43 & 51 at 51%

So basically we have 51% outside RH and 38% inside today.

2. The customer states it is on going, however, was way worse yesterday. (It was snowing, LOL) There other locations do not have as much static. I bet the other locations are not in a big building like this with 100% outside air at 55.

3. Ambient is the same as DB so it was definitely 70 degrees in the space, nice to know the Alerton stat was right.

4. Also the flooring is Bourbon Street 8mm Laminate w/2mm Attached Pad

I told them for initial relief to purchase a vaporizer, they can always take it back and that I heard there is a product that can reduce static Electricity.

[jburchstead]

Thanks for the update. The numbers do not make a "slam dunk" case for RH being the root cause of the problem but differential is definitely there. I agree with your recommendation to the client. It should mitigate the problem and is a low cost option. With a hair salon there are so many things that could be going with things like ionizing appliances and airborne chemicals you could spend a lot of time and money chasing this one any further. Good call.

[choice]

I wonder if reducing the amount of air changes would possibly raise the RH level a little.

[jburchstead]

Normally I would say no but in comparing your outside results with the indoor it doesn't like there is any moisture removal going on. Is it operating on an economizer? If so raising the supply temp. which would reduce the outside air might work.

[hvacker]

You know the trick with rubbing a comb through someones hair and making sparks. Maybe all the hair driers blowing on hair creates the static. I'd try grounding the clients.