Keeping your lab/workshop at a constant temperature - Page 1
Forum section: electronics / general

author: SKPang
author_rank: Unknown
timestamp: July 02, 2018, 09:28:16 pm
content: Does any of you guys try and keep your lab/workshop at a constant temperature ?My lab/workshop's temperature varies from 15°C in the winter to 29°C in the summer.I was wondering should I try and keep the temperature to say 22°C.

author: eurofox
author_rank: Unknown
timestamp: July 02, 2018, 09:38:26 pm
content: Quote from: SKPang on July 02, 2018, 09:28:16 pmMy lab is 22°C in the winter and up to 25°C in the summer.I log temperature and humidity.

author: cellularmitosis
author_rank: Unknown
timestamp: July 02, 2018, 09:44:03 pm
content: I've found that even within my 650 sq. ft. apartment, there is a considerable variation in the temperature swing as the air conditioning cycles on and off.There are areas of my apartment which swing through a window of 2C, while other areas its more like a 0.5C window.

author: JohnnyMalaria
author_rank: Super Contributor
timestamp: July 02, 2018, 09:50:04 pm
content: I keep my space at 25C (+/- a degree). The main reason is that the measurements I make should be done at room temperature and pressure (RTP) or standard temperature and pressure (STP, 20C). I choose RTP because most of the year I have to cool the space rather than heat it. e.g., today the outside temperature is 34C. Keeping the space at 20C would get expensive.If it gets too cold in the winter (e.g., a week of no more than -5C during the day), the heating struggles even to make 20C. In such case, I do something that doesn't require STP or RTP conditions. I have a couple of digital temperature and %RH meters in different locations so I can keep an eye on the conditions.Humidity isn't a concern because I measure aqueous liquids.

author: james_s
author_rank: Super Contributor
timestamp: July 02, 2018, 09:53:23 pm
content: As long as you keep the humidity in check, the temperature really comes down to what you are able to comfortably tolerate. Most equipment is fine over a wider range of temperature than most humans would like to spend time in, but condensation can be a problem.

author: TiN
author_rank: Super Contributor
timestamp: July 03, 2018, 04:37:34 am
content: QuoteThat is not correct question.Correct question is :What requirements do you have for your measurement / equipment?Do you have temperature sensitive equipment? If yes, what is sensitivity of that equipment and what tolerances are important for you. Laser diodes, resistors, sensors, ADC/DAC systems, are sensitive examples.Do you have metrology sensitive equipment? If yes, what acceptable accuracy your need from your standards and measurement equipment.Without knowing this information, and how bad (budget and effort) you want those requirements to be met, then you can see what the answer would be.Also equipment that need constant temperature will also likely to have optimal "sweet-spot" temperature, which can be +20c, or +23c, or +25c, or other value. Typical calibration temperature for bench DMMs and sources is +23c +/-5c.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: July 03, 2018, 11:37:01 am
content: My secret underground lair, being underground, is fairly well buffered against temperature changes. Still, it can get down to 62F in the winter, and up to near 80F in the summer. It's dehumidified and I keep it at about 60% RH. 50% is harder to achieve. My technical library is also in there, and you'd be surprised how much humidity buffering is provided by a lot of books! If I'm going to work in the winter, I'll leave the door open and put a few more logs in the wood stove. Maybe turn on a big tube scope and curve tracer. No cure for summer heat, but only when we have a heat wave does the temperature go up that much. Most of the year the room is right at 68-70F. I try to do all metrology stuff when the room is in that range because it's way too hard to characterize every possible piece of equipment and reference for a large range of temperatures.

author: IanJ
author_rank: Unknown
timestamp: July 03, 2018, 05:22:37 pm
content: Quote from: SKPang on July 02, 2018, 09:28:16 pmI see you are in the UK.....so I have the same problem in the same country.My workshop is a converted brick built garage, fully insulated, plasterboard, double glazed windows/door. Floor is raised/insulated.In the winter with snow outside it's still 15degC in there due to running a server rack 24/7.In the summer it gets out of control and gets to 30degC.However, I now have an Inventor Cool air-conditioner and can run it all year round and get +/- 2degC set temp.https://www.inventorairconditioner.com/air-conditioning/portable-air-conditioners/cool-air-cooler-8000-btuI have tried all-sorts over the years and this is the best yet. Best money I have spent.This is it installed in the corner and the vent piped outside, I really didn't want it in the way so this is what I came up with.Ian.

author: rdl
author_rank: Super Contributor
timestamp: July 03, 2018, 07:28:31 pm
content: My apartment is about the same size. I have a thermometer on my desk and the normal temperature variation is about +/- 2 degrees F. I think the bedroom/bath area is probably a bit more extreme as it is a bit separated from the rest of the apartment by a wall with a doorway. The main living area where the thermostat is located is basically one big open room.Quote from: cellularmitosis on July 02, 2018, 09:44:03 pm

author: CopperCone
author_rank: Super Contributor
timestamp: July 03, 2018, 11:49:25 pm
content: https://www.eevblog.com/forum/projects/can-you-put-a-vfd-on-a-regular-air-conditioner-or-refrigerator/

author: Dr. Frank
author_rank: Super Contributor
timestamp: July 04, 2018, 08:03:23 am
content: Doing metrology on analogue units is impossible without constant lab temperature.So I moved the whole stuff in our basement, which is well isolated to the outside.In winter, the regular heating is on.So, the temperature varies between 20°C in the coldest winter days , e.g. -15°C outside, and 23°C on the hottest summer days, like right now, up to 35°C.Most of the time, temperature is 21..22°C, and constant to a few tenths of °C over 24h.When all instruments are running, temperature might increase,so I mostly run the experiments on remote and lights switched off, to get rid of another 250W .Frank

author: Kjelt
author_rank: Super Contributor
timestamp: July 04, 2018, 09:58:37 am
content: I am thinking about buying a decent AC for my hobby room in the attick since on these hot days it is too hot there to do anything at least while wearing any clothes.Turning on the solderiron is horror.For the last 20 years it was unbearable about 8 to 12 days a year which was not that bad, but this year we already passed the 15 days of too hot weather and it looks like it is becoming worse the coming years.When I do buy it (costs will be at least $5000) I will also add an outlet in the bedroom since my nightrest is also badly influenced. The problem now is that I have to wait till it gets colder again before any firm has time to install it, so this year I am still

author: Monkeh
author_rank: Super Contributor
timestamp: July 04, 2018, 10:03:21 am
content: Quote from: IanJ on July 03, 2018, 05:22:37 pmNow if only they made one which isn't single hose..

author: CopperCone
author_rank: Super Contributor
timestamp: July 04, 2018, 03:11:43 pm
content: single hose is horrid. I have a 10000BTU unit that set at 62 fails to cool a room with a single computer that is about 10x12 feet adequately, it gets to maybe 74. With rockwool insulation and anderson windows. The heat sink on the air conditioner gets to 62 C, but with the air exchange it just does not work right. At least I have fresh air pulled from inside my walls and a slightly low pressure environment?A little 5000 BTU window unit did a good job, but I got sick of cleaning that fucking thing every year. You need to strip em down and wash it because you get all sorts of mold and bits of organic matter and other crap in them. And they are not cleaning friendly inside, tons of sharp edges, heavy, hard to get the chassis off., they rust.And you can't get sunlight well.After a decade of doing it I decided to get this interior unit, and now I want money so I can build a HVAC system.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: July 05, 2018, 04:06:37 am
content: Quote from: Kjelt on July 04, 2018, 09:58:37 amYour summer conditions are not that different to what is experienced in many areas of Canada, except we tend to be more extreme on both the warn and cold side. If you are confined to the attic (is it non negotiable?) and your nights are cool, say less than 15 degrees then one strategy which really works is a whole house fan. Much cheaper than air-conditioning which only gets used one month a year, I would try it first. Put a big high capacity fan at the highest spot you can and open some ground floor windows. Late afternoons will likely still be too hot upstairs but sleeping/nighttime can be quite comfortable. When you are about to get a hot spell you have to get ahead of the thermal mass of the roof and upper floors by starting the fan operations early, chilling them in anticipation of the hotter days which come later.I got by with this technique for decades.Edit: in case it is not obvious, the fan needs suck out hot air at the top, cold air will flow in naturally at the bottom as the system works with the normal convective flow. This is how prairie dogs (richardsons ground squirrels) keep their burrows cool - minus the electric fan.

author: Kjelt
author_rank: Super Contributor
timestamp: July 05, 2018, 06:50:41 am
content: Yes we sometimes do something like this on floorlevel, the lowest floor we can not open much due to security. I don't like to leave doors and windows open in the night, we had too many unwanted visitors robbing houses in our neighbourhood the past yearsThe biggest problem I can think off with this approach is that you have too little time and not enough cold to balance.In other words the internal mass of the house incl furniture etc. is heated 12 hours a day at 30C and you can't cool that down in 8 hours at 14C, each day on average the house gets hotter and hotter. That is what we see on the thermometer, it runs up after the hot period starts and never gets down to levels before.But a large fan on the ceiling could indeed be a good alternative.On the pro side of the AC it can heat the attick in the winter, I have a single thermostat heating so when the living room is at the temperature setting the heating shuts off and you guess it the attick can be cold in the winter. In the garage I have a three phase 5kW electric heater which brings it to pleasant ambience within 15 minutes

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: July 05, 2018, 11:27:23 am
content: Quote from: Kjelt on July 05, 2018, 06:50:41 amYou are correct in that many "physical plant" factors govern how effective this is. I used to live in Winnipeg which has a yearly -35C to +35C range every year with winters that are somewhat colder than Moscow's. Also massive spring floods. Blizzards. Clouds of mosquitoes every year and periodic plagues of forest tent caterpillars which strip the trees bare every 7 years. AlsoDutch elmdisease - I blame you guys! Winnipeg used to be known for its river elms. Also there are roaming gangs ofaboriginalfirst nations youths making it the car theft capitol of Canada. It really is a biblical plague kind of place. Avoid.Anyway with a one story wood frame house that had R40 in the ceiling I would start to lose ground day by day against the heat in the worst years. I had weapons and in those times a house wolf companion so I didn't have any open window security concerns. However one night I forgot the city was spraying malathion in my neighborhood for the mosquitoes mentioned above, and they filled my house with nerve gas. They spray every year overnight and you have to be on your toes and seal up your mansion-shack and suffer on those nights.My current house on Vancouver Island is two story wood frame with R40 ceiling R20 walls in the most temperate climate zone in Canada. In addition not much in the way of south facing glazing so the solar greenhouse gain is mild. On the worst day here it gets to about +32 upstairs in my lab and bedroom in the late afternoon and within 2-3 hours of starting the fan it is more than comfortable enough for sleeping. The overnight temp is abut 11- 14 C. If I put my hand up to the ceiling in the morning I can feel the sheetrock surface is still warm so there is some thermal carryover but overall the situation is quite livable.You need a big fan, like 1 horsepower or more and cool evenings to have any chance.

author: Kjelt
author_rank: Super Contributor
timestamp: July 05, 2018, 12:26:23 pm
content: Quote from: chickenHeadKnob on July 05, 2018, 11:27:23 amThat sounds terrible, but indeed mosquitos are not fun. But what about all the animals depending on eating the mosquitos like frogs, birds, bats ?QuoteThat sounds good, one small problem it starts to cool down around 22.00 here, before it remains around 28C in my attick it is 35C by then.Daytime I work, and after dinner around 19.00 I sometimes really would like to do stuff. Then I have to wait till 1.00 or so before the attick is livable.But hey I was never a really patient person. I can understand it works and is an economically good alternative.I think I'll start with ceiling fans , we don't have them and they can make quite a difference already.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: July 06, 2018, 02:20:44 am
content: Quote from: Kjelt on July 05, 2018, 12:26:23 pmI have the advantage of being a night-owl and not having to work regular hours so I sympathize. It cools down more rapidly here and that is critical. I doubt ceiling fans will do much, just blow the already warm air around.As far as Winnipeg's mosquito spraying is concerned that situation is total political theater and controversial. Ostensibly the spray program is given a public health excuse as a preventive measure against the spread of west nile virus but in reality people just want the government to do something, anything, because they are bothered. I grew up in part in Canada's remote north with even worse blood sucking insect conditions and developed a tolerance and so would laugh at the weaklings around me.The city sits on a glacial lake bed of heavy black clay, gumbo we call it. Every spring and early summer rains come and water collects on the surface in puddles just long enough to make ideal mosquito hatcheries. Those adult females then only live for 2 weeks so they naturally die off. It takes the city spray trucks about 2 weeks to make the full rotation through all neighborhoods.Complete theater. Oh you can tell the city not to spray at your address but that is like having pissing and non pissing sections of a public swimming pool. I wouldn't worry about the other animals running out mosquitoes to eat, you need to experience the conditions first hand to understand what I am talking about.

author: james_s
author_rank: Super Contributor
timestamp: July 06, 2018, 03:50:37 am
content: Oh man, I LOATHE mosquitoes! Those suckers absolutely love me too, if there's a mosquito around it will find me. Usually they come out as the sun sets and by the time I spot the first one buzzing around and make a run for the door I end up with a couple of bites. The only thing that really seems to work is Deet if I can remember to put some on any exposed skin. With all the woods and ponds around here I don't think the frogs and birds are going to run out of mosquitoes.

author: Kjelt
author_rank: Super Contributor
timestamp: July 06, 2018, 09:49:24 am
content: Quote from: chickenHeadKnob on July 06, 2018, 02:20:44 amThose puddles of water are the only ones that need to be sprayed then but that is probably Mission Impossible 10Both my neighbours have a pond, so now in May I can not sleep from the horny frogssounds and in June the mosquitos have a ball.I have a small itch from mosquitobites but my partner gets big hard bumps, I think she migh be allergic or something. So we have a hor for the window which unfortunately not only keep the mosquitos out but also the cold. Perhaps a small soundless fan would help there, blowing the cold in , any mosquitos that go for the ride will be splattered against the hor.

author: Lionered
author_rank: Contributor
timestamp: July 09, 2018, 06:11:00 pm
content: I have no specific workshop yet but I'm planning to make one very soon. I will keep it in a comfortable temperature depending on the weather but not that constant. A good and effective fan could do the trick.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: July 10, 2018, 03:15:54 am
content: Fans are good if you don't want to cook, but IMO they make for terrible high precision metrology. Probably best to have something set very low across the room, just to keep the air mixed, but never blowing across the bench. Unless you're soldering.

author: kj7e
author_rank: Frequent Contributor
timestamp: July 10, 2018, 05:24:48 am
content: Quote from: Conrad Hoffman on July 10, 2018, 03:15:54 amIts been over 105F last few days here, my lab is a extra room accessed through the garage under the main part of the house. I have a 10,000 BTU room A/C in the wall which does a good job keeping the temp in check but found its best if I direct the airflow high and away from the bench.

author: SilverSolder
author_rank: Super Contributor
timestamp: July 17, 2018, 04:19:44 am
content: I've found the best way is to use electric heating with a very precise room thermostat. My "cave area" easily stays within about 1/2 degree C after converting it to electric heating.Use a thermostat similar to this one:https://www.honeywellstore.com/store/products/5-2-day-programmable-triac-line-volt-thermostat-honeywell-rlv4305a.htmIt claims 0.25 C precision, but that probably assumes no air movement in the room! That said, it is amazingly good.It seems to work by "pulse width modulating" the heating elements with very slow pulses (several seconds) - I think it simply counts the number of AC cycles out of a "window" of 1024 cycles. So if it thinks 10% heat is called for, it will power ON for 102 cycles, and OFF for the remaining 922 cycles... the thermal inertia of the heating elements and the air in the room take care of the rest. The precision achievable by this is around 0.1% which is impressive, and it really works!A second major benefit of this approach is that the heating elements are kept relatively cool... closer to the target room temperature. So there are less issues with hot spots and convection around a very hot element. The more elements you have, the better (baseboard heaters are perfect). But you can also use electric oil filled radiators, as long as they are cheap and primitive (i.e. no electronics in them).You could do something similar in the summer, if you are willing to tolerate a higher temperature (or if you use A/C in conjunction with electric heating).