Author Topic: Temperature/thermal management in lab  (Read 2148 times)

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Offline tkamiyaTopic starter

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Temperature/thermal management in lab
« on: March 05, 2019, 03:38:11 pm »
How are you managing room temperature in your lab?  (assuming this is a home lab)  I have an air conditioner and heat pump that is capable of +/- 0.5C but that's only theoretical.  There is no sensor in my lab and room to room difference is quite large.  My lab happens to be the warmest room in the house and it's good 2C higher.  T-stat is set at 26C.  (yes, it's warm)

Even if I could put an independent A/C which I considered, equipment alone have enough BTU that will affect locally.  Also, we (human) are heat source as well, provided you are not at room temperature.  Air flows will affect as well.

My lab has no windows.  There WAS a window but it has been covered with a layer of plywood, two layers of insulation, and another layer of plywood.  There is a layer of acoustic foam on top of that, mostly for looks. 

If anyone has tips and ideas, I'd like to know.  Thanks.
 

Offline Conrad Hoffman

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Re: Temperature/thermal management in lab
« Reply #1 on: March 09, 2019, 06:32:35 pm »
My lab is in the basement. No windows. It's very stable, but I heat with a wood stove in the next room; the yearly swing is huge. I just work when the temperature is 68-73F. There's a dehumidifier in the room, so humidity is fairly well controlled. I also have many shelves of books and have discovered they buffer humidity swings rather well.
 

Offline tkamiyaTopic starter

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Re: Temperature/thermal management in lab
« Reply #2 on: March 10, 2019, 04:58:26 am »
I am seeing frequency drift are mostly caused by temperature changes.  The lab being closed environment and many "stuff" running at all times, it has the largest temperature swings.  I'm thinking of putting my house standard stuff neatly into a rack and relocating elsewhere in my house.  My older computers are basically a small room heater, too. 

You are lucky for having a basement.  In Florida, we can't have one because of water table being so high.  It'll become an  under ground water storage.  Only time we can have basement is when house is built on a small hill.  (which itself is a rarity)
 

Offline Mr. Scram

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Re: Temperature/thermal management in lab
« Reply #3 on: March 10, 2019, 01:24:41 pm »
I am seeing frequency drift are mostly caused by temperature changes.  The lab being closed environment and many "stuff" running at all times, it has the largest temperature swings.  I'm thinking of putting my house standard stuff neatly into a rack and relocating elsewhere in my house.  My older computers are basically a small room heater, too. 

You are lucky for having a basement.  In Florida, we can't have one because of water table being so high.  It'll become an  under ground water storage.  Only time we can have basement is when house is built on a small hill.  (which itself is a rarity)
I think a water cooled lab would be relatively stable temperature wise. Unfortunately, the calibration of some devices may suffer.
 

Offline rhb

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Re: Temperature/thermal management in lab
« Reply #4 on: March 10, 2019, 01:44:28 pm »
Look into a small "mini-split" just for the lab.  But be warned they are not cheap.  I'm about to install an 8 zone system in my house as the current system is dead.

If you are able to work on such systems or know someone who can help you you could hack one from a small window unit.  Fairly easy if you just need cooling, but significantly more difficult if you want to add a reversing valve for heating.
 
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Offline tkamiyaTopic starter

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Re: Temperature/thermal management in lab
« Reply #5 on: March 11, 2019, 12:05:36 am »
I placed an order for a short rack.  I'm going to put together all of my lab standard signal instruments and put it in corner of my living room.  There's enough air volume there it will be less affected.  Plus, it will be out of lab that has pretty big temp swings. 

I was actually thinking about mini-split.  But, really didn't want to go to that direction.  My house AC has zoning capability but that will be pretty costly as well.  Home improvement centers have mini A/C of various kind, including portable type.  I don't know how reliable they are for continuous use.  I have issue with noise and its a diagnosed condition.  So whatever I do will have to be super quiet and that usually mean cost.
 

Offline Johncanfield

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Re: Temperature/thermal management in lab
« Reply #6 on: March 11, 2019, 12:34:35 am »
Look into a small "mini-split" just for the lab.  But be warned they are not cheap.  I'm about to install an 8 zone system in my house as the current system is dead.

If you are able to work on such systems or know someone who can help you you could hack one from a small window unit.  Fairly easy if you just need cooling, but significantly more difficult if you want to add a reversing valve for heating.
I have a mini-split in my lab/ham radio room, they are very efficient and great for cooling a room.
 

Offline rhb

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Re: Temperature/thermal management in lab
« Reply #7 on: March 11, 2019, 01:27:33 am »
Mitsubishi and Daiken make systems with noise levels of 19-21 dB at the lowest fan speed.  I suspect other makers as well.  That is very quiet.

Noise has been my top requirement for a new system for my house.  No one installing forced air systems around here would even accept a job that required acoustic liner in the duct work.  The existing duct work is in the slab and I cannot tolerate the mold that grows in it.  So I needed all new duct work.  I was not about to spend over $16,000 only to be plagued by noise.  I find machinery noise *very* annoying.

Zoned forced air has a lot of issues.  I've got a commercial building that has one unit which is split into two zones.  Keeping both tenants happy is a real headache.  And the air valves are noisy and prone to whistle.
 

Offline tkamiyaTopic starter

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Re: Temperature/thermal management in lab
« Reply #8 on: March 11, 2019, 02:06:14 am »
I have no way to measure it's sound level but I have a top tier Trane unit.  Both outside and inside unit are super quiet.  I often don't know it's actually running.  My contractor loved the work as I didn't complain about spending $$ as long as the end result was a super quiet system.  I cannot tolerate noise.  I am so pleased with the choice I made.  Not only do I find noise uncomfortable, it triggers severe anxiety.  It's a very annoying problem.

I am now going through some of my test equipment and replacing fans.  Many are from 80s and very high quality unit (HP always have excellent fans).  But they are noisy.  Some smaller fans sound like a turbine.  Many inexpensive test equipment are surprisingly quiet.  (Such as my Siglent scope) 

Unfortunately, I cannot afford a good climate control system for my lab at the moment.  I spent all too much on test equipment.  If I'm going to do that, I'd rather add a room and put a mini-split there.  Might as well do it right.  My current room is too small.
 

Offline rhb

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Re: Temperature/thermal management in lab
« Reply #9 on: March 11, 2019, 01:55:34 pm »
ROFL We have all the same problems except I live in the midst of a bunch of hillbillies who don't want to work.  So even though I was willing to pay, they were not willing to do the work. I'm engaged in quieting all my test gear and computers, both acoustically and electrically.  I've got 5 computers, three monitors, two printers and 20 or so pieces of T&M gear in a 7 x 10 ft room.  I'll move it all eventually, but I wanted to be able to play at least some of the time.

My sister called 30 drywall contractors.  Not one returned her call.  It was deer season.

I was going to spend around $18K on a concealed fastener roof.  I contacted 4 companies, two showed up. Only one gave me a quote.  I asked him to give me quotes on a couple of built up commercial roofs I wanted to overlay with metal.  I have never heard from him since. 

I had a builder whom I've known since we were kids contract a composition shingle roof.  He brought in a crew of Mexicans from 80 miles away, none of whom spoke English.

 I gave it a careful inspection after the rain washed the loose granules off.  As good a job as if I had done it myself.  A full tear off and thirty five square in 8 hours by 5 men.   "Es no bueno.  Es perfectamente!"
 

Offline tkamiyaTopic starter

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Re: Temperature/thermal management in lab
« Reply #10 on: March 11, 2019, 02:38:33 pm »
Saaaaaaaaaaaame issues here.

Call 10 contractors, a few will return call, even fewer return second call, maybe one will give me a quote.  A couple of funny stories on roofing.  I had an older gentleman work on my roof from time to time for minor repairs.  His son is a full blown roof contractor.  (maybe not a good term to use....)    So when it came time to re-roof, I had his son's company do the work. 

Good enough work, fair price.  OK...  Then I had rats infestation problems.  Really bad ones.  It almost drove insane.  (this is NOT a figure of speech!)  All rates were unusually small.  This puzzled me and my rats guy.  (I hired a pro small animal catcher) 

Few weeks later, small animal guy wants to return my money and quit.  I talked him into staying with me.  He did.  A few months and futile effort later, I was looking at my new roof and something isn't right.  A vent pipe is missing.  Go inside the roof and sure enough, someone knocked off the bent pipe and its end is open in attic space.  BING!  I see some biting marks and dirt at the coupler.  I blocked it and rats issue stopped immediately.  BING!

Getting it repaired was easy.  Then I tried to recover $1400 animal guy bill.  He refuses and offers $50.  I refused that.  He leaves and gives me a call few days later.  He'll pay.  But only at $200 every two weeks.  I said sure, half not believing he will honor his words.  He did.  What a stressful process!

After all this, his son's company or his father no longer wants to do ANY work for me.  I thought I was giving them a break.  Oh no...  A very strange work ethic.  All Speaking staffing are nothing unusual where I live.  (Central Florida) so I didn't think anything of it. 

Similar story with my first A/C replacement with a cheap guy.  It involved hundreds of calls, a year of trying, and your honor to settle the thing.

After this, I no longer go with most guys and have a very strict criteria.  New AC guys are great.  They are probably most expensive in town but excellent work.  Anything AC or electrical stuff, they get my business.  And no more rats problems.

Now my neighbor feeds birds and squirrels.  Grrr....  MY ROOF!
I have a feeling your honor will have to help me out on this one, too at some point.
 

Offline IanJ

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Re: Temperature/thermal management in lab
« Reply #11 on: March 11, 2019, 08:43:39 pm »
Here in the UK my workshop gets really hot in the summer and down in the single digits in the winter......so I need heating & cooling.

- I bought a portable air-con (Inventor Cool) which cools via two modes, fan only & full cooling mode.
- I also bought a wall heater (500W).
- I added a USB temp/humidity sensor at far end of the workshop.

I hacked the cooler and basically gave it an IP address so I can control it via a Windows app. The heater is also interfaced the same way.

The PC app (with touchscreen) has all the bells n whistles to control both heating, and both modes of cooling via the remote temp/hum sensor.

Summer or winter the temperature is within 1degC of setpoint. It's pretty economical to run, I find that the fan only mode on the cooler is usually enough to bring any rising temps down unless it's a blisting hot day outside.

Pics attached including the PC app......you can see the heater has been going on & off most of the day......until a couple hours ago when I entered the workshop and my body heat has obviously helped raise the temp so the heater hasn't need to work so hard.

Ian.
« Last Edit: March 11, 2019, 08:45:36 pm by IanJ »
Ian Johnston - Original designer of the PDVS2mini || Author of the free WinGPIB app.
Website - www.ianjohnston.com
YT Channel (electronics repairs & projects): www.youtube.com/user/IanScottJohnston, Twitter (X): https://twitter.com/IanSJohnston
 


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