Cheapish environmental chamber  - Page 1
Forum section: electronics / general

author: loki42
author_rank: Frequent Contributor
timestamp: August 04, 2025, 02:32:37 am
content: I saw the recent post about environmental testing and remembered this has been my plan for a while. Are there cheap desktop options for small items? I mostly want to test at a range of temporary temperature and humidity to test cooling performance and see if we can find any issues. What's a sensible starting price point? I'd want remote control if possible, don't care too much about what interface, Ethernet, serial, gpib etc. 0-40c i guess?

author: thm_w
author_rank: Super Contributor
timestamp: August 05, 2025, 09:27:26 pm
content: Budget? cheap means $100 to some $1000 to others.Most important is temperature which can be done on a budget with a freezer and an oven separately, or if its small, some peltier unit like the one dave had. Search for refrigerated incubator. Though I don't think they are very good.Here is a compressor based unit:https://www.aliexpress.com/item/3256807529192849.html

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 06, 2025, 03:56:50 am
content: For DIY, heating is easy (modified toaster oven soldering controller) but cooling is a bit more difficult, as you will have to pull out all the heat energy that your gadget produces, and then some more to compensate for losses. If you only want to use it very occasionally, then cooling with dry ice or liquid nitrogen (and a way to dose it) may be an option.Or add a bigger fridge, and put in half a cubic meter of brine for the cooling.Humidifier is also quite easy with one of those ultrasonic devices (they do also spread the chalk from the water in the air), and de-humidifiers are also commercially available, but not quite cheap. If you have a cold reservoir you can cool circulate and cool the air to remove moisture, Or you can tap off the output of an air compressor, as a lot of water will have condensed in the compressor tank.Do you also want to regulate air pressure to simulate big heights above sea level? Air pressure influences both insulation distances on PCB's, and the effectiveness of heatsinks.

author: loki42
author_rank: Frequent Contributor
timestamp: August 06, 2025, 09:58:13 am
content: Oh I didn't think about air pressure. A few $k would be the max price. I'd be happy to look at used too as they seem to come up somewhat often but I'm unsure what specs matter or what is a good deal.

author: Berni
author_rank: Super Contributor
timestamp: August 06, 2025, 10:21:01 am
content: We just use a modified mini fridge.You can pick one of those up very cheaply and with the thermostat bypassed they can get down to around -20°C. The fridge also gives you a convenient insulated box with a sealed door on the front. So to turn it into a thermal chamber you need to add a heating element (for example the adhesive silicone heating pads from china) and an industrial temperature controller module (Comes as a neat little box that fits into a square panel cutout). If you look for long enough you can even find a mini fridge with a glass door, so that you can watch your experiment.If you need wire pass trough you can drill a hole for that, or just simply just run thinner wires out the door and close the door on it.If you also want to test for humidity you can add a warm bowl of water (near 100% humidity) in there or a pan of freshly baked out silica gel (near 0% humidity)Not the fanciest environmental chamber but it can be put together for 100 bucks.For air pressure things get tricky due to sealing and needing strong walls. For that we have a acrylic cylinder connected to a pump. The lid is not strong enough to go very high in pressure, but it can vacuum it down pretty well (Nothing approaching high vacuum, but the sort of vacuums seen by high flying aircraft is perfectly obtainable).

author: thm_w
author_rank: Super Contributor
timestamp: August 06, 2025, 09:03:18 pm
content: Quote from: loki42 on August 06, 2025, 09:58:13 amHeating and cooling capacity, how long its going to take to go from 0C to 40C. So if you want to cycle 0->40C 500 times, you don't want it to take a month. If you don't do temperature cycling testing its less of an issue.