Author Topic: Just installed my new temperature and humidity controllers  (Read 6511 times)

MAK

  • Guest
Just installed my new temperature and humidity controllers
« on: February 15, 2014, 06:21:06 PM »
Hello,

I wanted to show off my new temperature and humidity controller.  This was a fun DYI project.  Seems to be working good.

Dave

graysalchemy

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #1 on: February 15, 2014, 09:08:20 PM »
Nice set up.  :)

I have a temp controller but no humidity controller. :(

Did you use one of these and an stc100 for temp control?

MAK

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #2 on: February 15, 2014, 09:34:20 PM »
Nice set up.  :)

I have a temp controller but no humidity controller. :(

Did you use one of these and an stc100 for temp control?


Exactly.   I have a humidifier on the bottom of the refrigerator connected to an extension cord that is wired to the controller.  I have it set between 80% - 85%.   So far it seems to be working fine.   

Can I expect an unforeseen problem? 

graysalchemy

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #3 on: February 15, 2014, 09:51:27 PM »
I may get one of them they look quite good and cheap as chips.  :)

John@PC

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #4 on: February 16, 2014, 03:33:17 PM »
Great job on the project Dave.  For anyone who may not have the knowledge or desire to DIY we do make (here in SC, USA) and sell fully-wired ready to use systems (temperature and humidity) and also have just started offering a 2-stage (2 relay) controller for people who have their caves in unheated areas.  Like you we use the WH8040 humidity along with WH7016's temperture controllers and buy them direct from Willhi in Shengzing.  Originally we had a "dual" unit with both (temp and %RH) controllers in one box but found the cost wasn't that much more than for separate "boxes", and there were several advantages like using the temp controller for other applications like heating milk and cooking sous vide.   I won't go into any more detail for fear of the forum advertising police knocking at my door  :o but for those that are interested there is more info on the links.  A picture of my DIY / DIFO (Do-it-yourself and Do-it-for-others :)) controllers on my cave set up are attached. 

retrojim

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #5 on: May 15, 2014, 05:50:15 PM »
Nice job!

I'm using an old small wine fridge for my cheese cave, and it doesn't have any temp or humidity displays. Since one of my other hobbies is electronics I looked through my junk drawer and found enough parts to build a temperature and humidity display using a DHT22 temp/humidity sensor. First thing I noticed was that my wine fridge was running too warm, so now I've got it down to 55 degrees F.

The next problem I need to solve is humidity. Putting a container with a wet sponge in the bottom of the fridge is wildy inconsistent depending on where I put the sensor, but I have't seen it get over 60%. My solution is to raid my junk drawer again for a small fan that I will place over the sponge container to circulate the moist air. I have a fan that runs pretty gently so it shouldn't disturb any mold cultures. Once I get the humidity up I'm going to attempt some St. Marcellin. I've only aged hard cheeses in the cave so far, mostly waxed cheddars.

Since I'm using a small AVR micro controller for the sensor and display I'm going to hook up the fan to it as well so the micro controller can turn the fan on if the humidity drops below a set point.

Total material cost of this project was $0 since I had all the parts lying around, but if I had to buy them it wouldn't be much more than $20. The most expensive part is the 2 line backlit LCD display at about $10. If I really want to get fancy I could hook up an IO pin on the micro controller to an AC relay, put the fridge on high, and let the controller cycle the power on and off to control temperature too, but I don't think I need to do that yet.

I love it when my hobbies cross pollenate!

--Jim

AKASTUDY

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #6 on: July 13, 2015, 07:32:35 PM »
Don't beleive all you see!
I'm controlling my fridge temperature and humidity using two controllers (see photo). The controllers are also connected to a humidifier and an old computer fan which kicks in when the temperature gets to high. Temp control is brilliant.
The humidity controller displays the correct humidity but when checked against a data logger was out by 25%. Humidity was still being controlled within a tight band.
I can't get the humidity up any higher and I suspect the sensor is getting saturated by humidity!
Anyone else had this problem.

AKASTUDY

John@PC

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #7 on: July 13, 2015, 08:59:03 PM »
Don't believe all you see!
Hi Akastudy and welcome :).  My experience is that resistive-type sensors like the ubiquitous DHT-11 used on many commercial electronic %RH meters (and dataloggers) are more prone to saturation and off-readings than are the capacitive sensors like the you have with the Willhi controller. If you don't have a certified instrument the best way to tell is do a calibration test in a saturated-salt environment.  I've attached a pic of 4 MH13001 controllers I've got calibrating right now using a wine-carafe with a tablespoon of table salt and a tablespoon of water.  Equilibrium %RH after 24hr should be around 74-75% and any error can be minimized with the controller's offset (in your case the CA function).

I know this is a lot of jargon to many cheese makers but they do need to remember your warning about blindly trusting what you see.  In your case you (probably) have one of the sensors that is significantly off - you just have to figure out which one ;)

abigail-watson

  • Guest
Re: Just installed my new temperature and humidity controllers
« Reply #8 on: October 11, 2016, 03:13:17 PM »
I never realised this sort of support existed - I'll probably be bugging you all with silly questions and queries about many a thing. My partner and I have a cheese shop in the South, and we've been through a few fridges and freezers. The freebies are awful - we ended up giving ours to my nephew... We bought one of our display fridges for our cheeses here - www.refrigeration-freezers.com/ and it has been awesome! However, hubby wants a new temp thremostat...