Make or buy a temperature chamber in UK - Page 1
Forum section: electronics / testgear

author: trevwhite
author_rank: Frequent Contributor
timestamp: April 05, 2017, 07:45:48 am
content: I need a temperature chamber that can do 0, 25C and 40C primarily but thinking if I am sourcing one it would be useful to extend the range but all depends on costs and size. I want something to regulate the temperature within a degree or so.Anyone know of a good source for one of these? My feeling is it is not a product that is likely to be cheap. I am semi open to making one but I think it would take up too much time unless it was off the shelf stuff and maybe a day of work.ThanksTrev

author: slurry
author_rank: Regular Contributor
timestamp: April 05, 2017, 08:40:48 am
content: I would say go the DIY-routean old stainless steel fridge (restarant bench model variety) with a good lock is a great start and a put some money in a really good thermostat and tempcontroller setup with graph/logging and all that fancy stuff.

author: nctnico
author_rank: Super Contributor
timestamp: April 05, 2017, 09:03:21 am
content: There is a thread somewhere about converting a fridge into a temperature chamber. Found it:https://www.eevblog.com/forum/projects/diy-temperature-chamber/msg189860

author: nfmax
author_rank: Super Contributor
timestamp: April 05, 2017, 09:07:21 am
content: You might convert a hotel mini-bar fridge. The cost should be trivial so long as you leave the contents behind!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 05, 2017, 09:13:03 am
content: Quote from: trevwhite on April 05, 2017, 07:45:48 amHow big a thing do you need to heat/cool ?

author: trevwhite
author_rank: Frequent Contributor
timestamp: April 05, 2017, 09:16:59 am
content: Thanks for the responses.Believe it or not, the primary requirement is to profile a LiFePo4 battery. To do this I need charge/discharge curves at 0C, 25C and 40C. The battery pack is only 5cm x 7cm x 2cm approx.It would be nice to use it for board testing as well but my urgent requirement is for the battery profile job.

author: vealmike
author_rank: Regular Contributor
timestamp: April 05, 2017, 09:35:07 am
content: Sounds like a job for a Peltier based coolbox.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 05, 2017, 09:46:40 am
content: Yes - a peltier is totally viable for that size.

author: 0xfede
author_rank: Regular Contributor
timestamp: April 05, 2017, 10:17:53 am
content: Peltier may be limited at 0C since you have to pump away the heat generated by the battery pack.Can you make an example of discharge power?

author: trevwhite
author_rank: Frequent Contributor
timestamp: April 05, 2017, 10:28:01 am
content: In theory then I should be able to flip the polarity and enable the chamber to become a heater as well.I do not think the battery itself is going to generate much heat so I think the diy project example seemed to suggest a temperature variation of maybe a degree or so. I think I could possibly calibrate this with a few dry runs.I got a quote for a new chamber. The cheapest the company said they did was £7k. If I wanted to hire one it would be over £300 for a week and it would cost £187 delivery each wayI dont really want to mess around but from the information on the diy version it does look doable for this particular application.Thanks everyone.Trev

author: EEVblog
author_rank: Unknown
timestamp: April 05, 2017, 10:53:53 am
content: It all depends upon how fast you want to ramp, and how much thermal mass and if it's dissipating significant power or not.If slow is ok and a low powered product, then one of these is fine. But it won't go down to zero though.

author: trevwhite
author_rank: Frequent Contributor
timestamp: April 05, 2017, 10:55:59 am
content: And it is also dependent on the ambient temperature. I would need to ensure that is stable when I set the thing up.Slow would be find I think and I do not think there will be a lot of heat being generated from the battery during the testing.

author: trevwhite
author_rank: Frequent Contributor
timestamp: April 05, 2017, 11:12:26 am
content: They actually sell the unit Dave tested here in the UK. 3C is pretty close. I wonder if I can get away with that!

author: trevwhite
author_rank: Frequent Contributor
timestamp: April 05, 2017, 12:28:13 pm
content: I just found one at Maplinhttp://www.ebay.co.uk/itm/Maplin-Gadget-Maxi-Fridge-Cooler-Heater-25L-AC-DC-48W-LCD-Temperature-Display/192112639808?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40656%26meid%3D8fe5adfc19d34f1b9f6a6273b7e0d6e9%26pid%3D100005%26rk%3D4%26rkt%3D6%26mehot%3Dpp%26sd%3D262900509391Half the price of the ebay incubator version. But it states not to be used for longer than 10 hours at a time? I cant figure why that would be true