42.5cu.ft. Drying Chamber 1 Year Review

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JC in GB JC in GB
Got the GEYA timer rely in yesterday and hooked it up. Dialed it in over a number of cooling cycles. Settled on a 4 minute delay on the radiator fans to allow the Peltier units to drop the cooling water temp. down to 11.4*C (measuring the temp. in the reservoir) before starting air circulation to cool the chamber. This is the temp. of the water before it enters the first peltier unit where the temp. will drop an additional 1*C prior to flowing into the first two radiators.

3*C is 5.4*F; and a larger delta than start up with the fans running. That larger delta helps tremendously with faster cool down as water being more dense than air can hold 25X more heat than air. This is a kind of reserve affect...

I plugged in my spare temp. controller and put the temp. probe in the reservoir to monitor it. it was at 11.4*C but flipped to 11.5 when I snapper the pic.
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This is the chamber temp. controller temp. at the start of cool down.
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I just watch the RH% controller and if the RH starts dropping then I know the cooling water is too cold.
 
So....had an idea last night while watching the system perform......I can't help it....things just come to me and ideas pop in my head.

Pulling the cooling water temp down 3*C made the chamber temp drop very responsive at the start. But the Delta between the chamber temp. and the cooling water would become smaller as the cooling cycle progressed, settling on 2-2.2*C delta. So....
I am considering running a test. I have a spare complete 180W Peltier unit. I'm thinking of setting it up to cool the return flow prior to going into the reservoir. I can put this unit on a temp. controller to pull the temp down to optimum which is around 11.5-11.7*C then shut off because I do not want the cooling water to get any colder than that or condensation will start on the radiators which I want to avoid. As the cooling water warms, the auxiliary peltier unit can kick on to help handle the heat transfer and keep the delta optimum for efficient cooling without condensation.

I will need another power supply eventually, but will use the 30 amp I have for the lights to run the test....
 
O.K., I set it up and ran the test.

Here are the results:
Delta maintained @3*C
Cooling cycle time 11:15 minutes; target temp. 12.7*C.
Radiator fans run 9 minutes (2:15 minute delay with timer relay)

The system shuts off to allow the chamber to warm to high set point of 13.3*C; this takes 12:45 minutes.

So the cooling cycle with fans running is 9 minutes, system at rest with no fans running 15 minutes.

Cooling cycle with fans operational is 37.5% of the time; 9 hours per day. Whereas before the cooling cycle with fans operational was 58.33% of the time, or 14 hours per day.

I now have another upgrade to make on my chamber. This is great! I am also going to install a visual flow meter (one that uses an impeller that spins) for a visual check that the pumps are operational and I have flow.

My chamber just became that much better!!!
 
I had a 90mm X 90mm X 25mm cooling fan go out on one of the TEM heat exchangers. Upon inspection, it had froze up. Time to change it. While doing that, I noticed the cooling fins on the exchangers were very dirty...time to clean them.
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Got them cleaned up; went ahead and installed 3 new fans rather than just one....replaced all the cheap china stock fans on the TEM exchanger.

Then I cleaned the other TEM exchanger that has been up and running for over a year. This will have to be done annually. But it does not take long and is easy to do. I was very interested if this affected the response time for chamber cool down, and it did! Cooling cycle has dropped from 9 minutes down to 8:35 minutes for a 1.44*F air temp. drop in the chamber. So awesome!!!
 
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I had a 90mm X 90mm X 25mm cooling fan go out on one of the TEM heat exchangers. Upon inspection, it had froze up. Time to change it. While doing that, I noticed the cooling fins on the exchangers were very dirty...time to clean them.
View attachment 669000
View attachment 668999
Got them cleaned up; went ahead and installed 3 new fans rather than just one....replaced all the cheap china stock fans on the TEM exchanger.

Then I cleaned the other TEM exchanger that has been up and running for over a year. This will have to be done annually. But it does not take long and is easy to do. I was very interested if this affected the response time for chamber cool down, and it did! Cooling cycle has dropped from 9 minutes down to 8:35 minutes for a 1.44*F air temp. drop in the chamber. So awesome!!!

Nice. When you order fans, if you haven't yet, get ball bearing fans. They last longest IMHO. You can also possibly get fans with higher airflow if that would help.

JC :emoji_cat:
 
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I did order ball bearing fans JC... these are rated for 78,000 hours continuous duty...and since the fans are only running 12 hours a day, they should last a while.
 
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I finally got around to downloading the App for my new Govee temperature and Hydrometer sensors. I got the H5179 WIFI and the H5072 Bluetooth. I wanted the WIFI so I could monitor my chamber when I am out of town. Both units work great and the sensors are both ultra sensitive, but I am finding that the H5179 WIFI unit is slightly more accurate. Cajuneric Cajuneric is right, these units WILL help you dial in your chamber to perfection. I love the fact that I can look at an entire day's worth of data at a glance for a birds-eye view. I love the running avg. so you know exactly what your humidity is doing.

And the best part for me is the dew point tracker. I know at a glance where to set the controller for the cooling water in the system so I do not go below the dew point and start getting condensation on the heat exchangers.

I am running the cooling water down to 10*C with the dew point @9.8*C....no condensation. I get very responsive cool down with the delta between the chamber temp. and cooling water temp. @3.3~3.4*C.
So awesome! If you do not have a Govee, you need to get one! Best $20-30 bucks you will spend on dialing your chamber parameters in to perfection! I am running 12.9*C and 79.7%RH!
 
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Made a few more upgrades to my chamber. replaced the homemade reservoir (made from a 1qt. Coleman insulated water jug) with a smaller 180mL sealed CPU water cooling reservoir with threaded ports for hose barb fittings. I'm insulating it with 3/4" foam board using double stick tape. That worked out great!
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Temp. probe of the radiator fan controller fashioned into place inside a spare hose barb fitting using silicone rubber. That worked great too! (this will be screwed into the top of the tank.)
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Also installed a passive flow meter and a pressure relief cap. (This is necessary to preserve your pump seals so there is no pressure in the tank when you screw the cap on).
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regular fitting installed on top to slide a funnel over for filling the tank.....
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Did a permanent install on the 3rd TEM cooler as well. I already had the spare base from when I made the original bases.
IMG_20230818_120056.jpg

Also upgraded to the best CPU cooler made on the market. Made by Noctua...140mm fans and the cooling fins are 150mm wide! Easily 75-100% more surface area and the fans blow a HUGE amount of air. I was able to get 53% more cooling capacity with this upgrade alone.

I was able to eliminate about 2' of hose and roughly 350mL of water from the system with the change for more efficient cooling and less wasted energy. The system is definitely more responsive. I installed the 3rd TEM in the middle between the original 2. I planned for this when I did the original layout on the design in case I needed 3 TEM units. With (3) 180W TEM chillers, I have 540W of power which generate roughly 400W of actual cooling capacity. This has increased the cooling rate of the system such that the cooling cycle has gone from 12 minutes to 5.5~6 minutes to drop the chamber 0.8*C. This along with the dual fan controls has this chamber dialed in to perfection.

I also installed a controller on the radiator fans using the cooling water temperature. When the cooling water reaches 10*C (50*F) the controller cooling switched off. This switches the relay switch off (normal open) and allows current to flow to the radiator fans. If the cooling water temp. rises 0.3*C, the relay flips on and current to the fans is switched off. (power on opens the contacts).
IMG_20230818_131147.jpg

Doing this works great when the chamber is dialed in @ operating temps., but if the power goes out I needed an override to by-pass this switching mechanism thru a parallel circuit. (controller on the left is for the radiator fans, the one on the right is the by-pass) I am wiring that up now....should finish this up tonight.

By pass temp. probe...I installed that on the wall between the double doors about 3/4 the way up from the floor....between the two sets of lights.
IMG_20230816_174813.jpg


Chamber Temp. Probe...
IMG_20230816_174818.jpg


I'll be ready to hang some new projects once the peak of hurricane season is over. Probably around October 1st. Then, I'll fill the chamber up again.

Now to finish up the last little details and dial it in using the Govee monitors I just bought!
 
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Got the Temp. system dialed in....
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Here is the time stamp of the start of the cooldown cycle...
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...and when cooldown is complete...
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About 7 minutes, then about a 14 minute warm up and cooling water pre-chill down to 49-5~50*F before coolown starts again. That's as low as I can go with 80%RH before condensation on the radiators.
 
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Now to start optimization on the dH system... beginning with installing a solenoid shut off valve on the return air to the chamber.

(Bench top testing the flow thru the valve....it'll work!)
IMG_20230828_181504.jpg


This will stop passive flow (venturi effect) of humid air from the dH fridge to the main chamber...thus trapping all the removed humidity in the little dH refrigerator so there is no bleed back. It will also keep the cold air in during pre-chill/ air drying prior to the dH cycle.
 
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I also bought a Label maker bluetooth capable to my phone with an App. I looked at these label printers about 15 years ago and they were $50-60 bucks (no bluetooth, had to type on the label maker key pad). The technology has lowered the price....picked that one up for $14 bucks on Amazon. Made a bunch of labels for the controllers and such on the chamber.
IMG_20230827_195409.jpg


Great for the Calibration too!
IMG_20230827_195353.jpg


Also printed an 'H' and a 'dH' sticker for my humidity controller. If you have an inkbird, you know why I did that!
IMG_20230828_205116.jpg
 
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Also replaced all the 60mmX60mmX10mm cooling fans in my power inverters from sleeve bearing fans to ball bearing fans. I caught a sale...less than $5 bucks a fan for 78,000 hour fans. I had already lubricated the sleeve bearing fans once. Now I don't have to worry about that anymore. And the fans are super quiet.
 
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DeHumidification Optimization complete...

After installing the Govee thermohydrometer in my little dH fridge and getting about a weeks worth of data, I could figure out which direction I needed to go to optimize the system. Biggest issue- I needed a recirculation fan. Ice builds up on the frost plate with 20kg. or more of product hanging in the chamber. With a recirculation fan, the airflow can defrost the ice when the dH fridge is shut off as it warms slightly.

So...pulled out the aluminum plate leftover from my build and cut out a baffle plate for the fan. Then I went to my buddy's shop to borrow the plate bender. I wanted to direct airflow to both the back and front of the frost plate with the recurc. fan, so the plate is on a 45* angle with holes drilled in the bend at the top and a little lower on the vertical surface. The holes in the bend direct airflow over the frost plate to the back of the fridge and behind the frost plate. The lower holes direct airflow to the front of the frost plate.

Holes in the baffle plate for recirculation airflow...
IMG_20230913_151141.jpg

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Plate for recirculation fan installed...
IMG_20230913_153433.jpg


Solenoid valve installed...(with an 3rd dH cycle circulation fan installed on the valve inlet). This is the return flow to the drying chamber.
IMG_20230913_160827.jpg

Still need to fashion a bracket to level the valve. Got it sitting on blocks right now..

Wires run thru the door...
IMG_20230913_163057.jpg

IMG_20230913_163112.jpg


I also made a dH water reservoir shelf while I was cutting and bending aluminum plate. I had some blue Krylon Fusion paint leftover from the build (painted the dH baffle plates and return header in the chamber blue) so I used that to paint the shelf.

I finally broke down and bought rivet nut compression tool. Prices have come down a lot since last time I was looking some 15 years ago. This one came with 9 mandrels both SAE and Metric. paid ~$30 bucks for it.
IMG_20230912_215046.jpg

So much easier with the compression tool!

The shelf is made so that it can be attached on either side of the chamber depending on where it is put in a room.
IMG_20230912_221037.jpg

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mounted the shelf about 2" taller than a 5 gallon bucket..
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I am logging parameters now with the Govee. Then I can program the dH system controllers for automation. Should be done in about another 2 hours....after the next cycle...
 
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DeHumidification Optimization complete...

After installing the Govee thermohydrometer in my little dH fridge and getting about a weeks worth of data, I could figure out which direction I needed to go to optimize the system. Biggest issue- I needed a recirculation fan. Ice builds up on the frost plate with 20kg. or more of product hanging in the chamber. With a recirculation fan, the airflow can defrost the ice when the dH fridge is shut off as it warms slightly.

So...pulled out the aluminum plate leftover from my build and cut out a baffle plate for the fan. Then I went to my buddy's shop to borrow the plate bender. I wanted to direct airflow to both the back and front of the frost plate with the recurc. fan, so the plate is on a 45* angle with holes drilled in the bend at the top and a little lower on the vertical surface. The holes in the bend direct airflow over the frost plate to the back of the fridge and behind the frost plate. The lower holes direct airflow to the front of the frost plate.

Holes in the baffle plate for recirculation airflow...
View attachment 676034
View attachment 676035

Plate for recirculation fan installed...
View attachment 676036

Solenoid valve installed...(with an 3rd dH cycle circulation fan installed on the valve inlet). This is the return flow to the drying chamber.
View attachment 676037
Still need to fashion a bracket to level the valve. Got it sitting on blocks right now..

Wires run thru the door...
View attachment 676038
View attachment 676039

I also made a dH water reservoir shelf while I was cutting and bending aluminum plate. I had some blue Krylon Fusion paint leftover from the build (painted the dH baffle plates and return header in the chamber blue) so I used that to paint the shelf.

I finally broke down and bought rivet nut compression tool. Prices have come down a lot since last time I was looking some 15 years ago. This one came with 9 mandrels both SAE and Metric. paid ~$30 bucks for it.
View attachment 676028
So much easier with the compression tool!

The shelf is made so that it can be attached on either side of the chamber depending on where it is put in a room.
View attachment 676029
View attachment 676030
View attachment 676032
View attachment 676031

mounted the shelf about 2" taller than a 5 gallon bucket..
View attachment 676033

I am logging parameters now with the Govee. Then I can program the dH system controllers for automation. Should be done in about another 2 hours....after the next cycle...

I am simply awestruck by the work you have done on this chamber. Such an amazing piece of equipment. Words fail me. A sincere hat tip to you sir.

JC :emoji_cat:
 
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Got the Temp. system dialed in....
View attachment 674674

Here is the time stamp of the start of the cooldown cycle...
View attachment 674675

...and when cooldown is complete...
View attachment 674676

About 7 minutes, then about a 14 minute warm up and cooling water pre-chill down to 49-5~50*F before coolown starts again. That's as low as I can go with 80%RH before condensation on the radiators.

I didn't notice this the first time I looked at the chart. Your temp is regulating usually within 0.3 C

Very impressive control system.

JC :emoji_cat:
 
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Very impressive control system.
Thanks JC. Studying engineering, control systems are right in my wheelhouse. My weakness is the electrical systems set up and how to wire it up. I am having to read refreshers....and redo some stuff....but I am learning and getting better at it. Thanks for your help with components.
 
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