Relative humidity in your lab and instruments

[mcinque]

I live in the countryside, and during winter my house is always at 70-78% relative humidity while in the summer it goes down to 55%. During winter rains, the value rise up to 85%.

I fear this high values could have a bad effect on the life of my istruments  (oxidation, rust on the inside etc). Most instrument's specifics allow 90% (non condensing of course!) relative humidity so I should sleep well.

The only advantage I see with that values is that I shouldn't fear static charge 

What do you think about instruments and relative humidity?

What values do you have in your labs?

[Mechatrommer]

here in the equator, 90% RH is pretty common throughout the year. my only concern is lenses' internal developing fungus so i got one nice diy drybox next to me for them "only".

[SeanB]

Winter the RH might drop to under 50% but at the moment it is 78% and 25C. Might start to use the fan soon, and possibly the AC as well on the really warm days.

[all_repair]

Now I run a dehumdifier 247, and reuse the water collected.
Before that I used a defective fridge as my dry box and use drying agents to dry the box.  I like use to fridge as a storage if I can find more place.  It is one equipment that is specially designed for putting in numerous items and still ease their movement, and also designed to take in many form factors.

[Terabyte2007]

If you can, use central climate control. I have a whole house humidifier with a humidistat which ranges from 10% to like 95% which I usually keep around 48% to no more than 60% depending on the needs. This is just enough to keep static to a minimum. The central AC in the summer will dry out the humid air, but you may need to still run a humidifier depending on the efficiency of your AC system. I have various temp and humidity gauges around the house for monitoring so I can try and keep things at a nominal temp/humid. I also use a moisture meter to check floors, walls, carpet, benches, tables and furniture from time to time. I know that sounds extreme, but I lived in a house years ago that had no climate control and after 10 years it ruined quite a few items including some camera equipment and personal memories stored away. Anything above 70% humidity, mold starts to grow. This can affect health and damage property. Also, if you read your specifications thoroughly as I do, the relative operating humidity of most equipment is no more than 80-95% humidity max unless it is rated for high moisture environments. Personally, this is what I do, and I am just sharing this to give you an idea as to what others may do. In general, I try to maintain an optimal environment all year round, I firmly believe this enhanced your health and preserves your property and delicate memories.

[echen1024]

Here in Houston, we have a 78% AVERAGE humidity around the year, but since my lab is central air conditioned, the house is typically at 60-70%. It's at 61 right now since a cold front just came in.

[Tepe]

41% right now here in my little man cave. Outside, it is currently 97% RH.

[dr.diesel]

65% in here now, but we've had a strong warm front come in, news mentioned 2" hail is possible this afternoon!   

A big fan of fresh air here, windows are open all the time in the spring and fall, humidity is all over the place during those days.  Dead of summer AC is on, nice cool and dry.

[mcinque]

Thank you all for your replies.

I have a dehumidifier, but I cannot use 247.
My worries are about instrument life and RH.

[nctnico]

I wouldn't really worry about humidity. The only real concern is taking a cold instrument into a warmer area. The moisture can condensate and cause arcing. This happened to me once causing the mains fuse on an oscilloscope to blow.

[mcinque]

I wouldn't really worry about humidity.

This is reassuring.

The only real concern is taking a cold instrument into a warmer area. The moisture can condensate and cause arcing. This happened to me once causing the mains fuse on an oscilloscope to blow.

Oh yes, this has been always a clear warning written in every electronic device manual since I was young. Thank you anyway for the advice 

[Lightages]

I have an average of 3% - 5 % here. Humidity? What does that mean?

If you live where humidity is a constant problem it is best to keep your equipment a bit above ambient temperature. This is usually easily accomplished by merely leaving it running.

[mcinque]

I have an average of 3% - 5 % here.

 

If you live where humidity is a constant problem it is best to keep your equipment a bit above ambient temperature.

It's a good advice.

This is usually easily accomplished by merely leaving it running.

This is hardly achievable, I can't leave the instrument always powered on...

[Cdngreybeard]

As a Western Canadian, low humidity is the big issue.  When it's -40 outside, it's pretty well impossible to get the house above 10% RH. In the summer it's rare for the humidity to go above 55% RH.  The big problem here is static.

[synapsis]

I'd rather have humidity than the 3-8% we usually have around here (Arizona.) Static is a *huge* issue. I can't even put a USB pendrive into the computer without touching the anti-static mat on the bench first.

I've been in the habit of tapping the sides of doorknobs and car doors with the "meaty" side of my hand to discharge before I open a door for over 20 years. It's sorta neat to watch the cat move under a shaggy blanket in the dark tho.

[ndzied1]

Wow. 3% ...  That is dryer than a popcorn fart!

[Lightages]

Yes, I live in the driest desert in the world, the Atacama Desert in the north of Chile. I am also at 2500 metres altitude (8000ft).

[madshaman]

What's a good relative humidity to aim for.  I have ionisers over my bench area so static is not a problem.

I'm thinking "low as possible" is the best choice, but I might be overlooking something.

I also like fresh air but I'm not above hacking something together to have both fresh air and low humidity.

One problem I have in my lab is that I use one of those small peltier-based coolers to store my solder paste.  The area where the cooler's wall contacts the peltier element constantly cakes up with ice and I have to periodically chip it off.

[Lightages]

What's a good relative humidity to aim for.  I have ionisers over my bench area so static is not a problem.

Generally the recommended relative humidity range for a measurement lab is between 30% and 50% at around 20°C to 25°C. Stay in the middle of that and keep it stale and it will be OK. Lower humidity is almost never a problem except for static electrical buildup.

[mcinque]

Ok for the static, but what about instruments life and parts? A mid-high RH (70-80%) can affect negatively the life of the bench instruments or stored parts?

[zapta]

I have an average of 3% - 5 % here. Humidity? What does that mean?

Almost a 1 percenter.

Sent from my Galaxy Nexus using Tapatalk 2

[AndersAnd]

I would be more worried about the well being of human beings than the well being of electronic equipment when trying to adjust the indoor climate to the optimal relative humidity. Electronic equipment are often quicker and cheaper to fix or replace than human beings.

http://www.engineeringtoolbox.com/relative-humidity-d_895.html

For humans relative humidity below 25% feels uncomfortable dry. Relative humidity above 60% feels uncomfortable wet. Human comfort requires the relative humidity to be in the range 25 - 60% RH.

The labour organization here in Denmark also recommends 25 - 60% RH for indoor workplaces - lowest in during the winter and highest during the summer: http://www.indeklimaportalen.dk/indeklima/luftkvalitet/krav_og_regler/

To avoid dry eyes and eye irritation from dust and contamination, at least 30 % RH is recommended. Heat and air draft is other causes for dry eyes, which is why a fan blowing directly in your face is a bad idea.
Below 45 % RH during the winter months is recommended to avoid problems with mold, house dust mites etc.
http://www.indeklimaportalen.dk/indeklima/luftkvalitet/toer_luft/handling/

Below 45 % RH, especially during the winter is also recommended by Asthma-Allergy Denmark:
http://dinhverdag.astma-allergi.dk/indeklima/tjekdinluftfugtighed

[madshaman]

What's a good relative humidity to aim for.  I have ionisers over my bench area so static is not a problem.

Generally the recommended relative humidity range for a measurement lab is between 30% and 50% at around 20°C to 25°C. Stay in the middle of that and keep it stale and it will be OK. Lower humidity is almost never a problem except for static electrical buildup.

Perfect!  Thank-you.

[codeboy2k]

Below 45 % RH, especially during the winter is also recommended by Asthma-Allergy Denmark:

42. The answer to life, the universe, and relative humidity

[Alexei.Polkhanov]

Yes, I live in the driest desert in the world, the Atacama Desert in the north of Chile. I am also at 2500 metres altitude (8000ft).

Place like this is my dream - I hate rain. Let me guess - your job is related to Astrophysics? 

[Lightages]

I actually have more to do with astronomy in general. I do public tours, design and maintain telescopes and observatories, observe, and also run a multimedia production company. This is the est place in the world for astronomy.