Been meaning to comment on this for a while. Thanks for this video. Good, quick explanation of the process. It nice to have this video to steer viewers to when they ask for a simple, fairly complete, how-does-it work video. (I would complain about the pressure sensor location vs temperature probe/thermistor location) 😁 But that doesn't change the function of the machine or how understandable the video is.
thank you for this explanation. @schoolreports sent me here when I asked for a basic non techy explanation. This definitely fit the bill. Would love a video that explain the presets under the customize button and why/if you would want to change them. Maybe it's already out there and I just haven't typed in the right words in the search bar? When watching videos of FD with the older firmware it's confusing to try to "translate" that into the newer firmware and understand exactly what I need to do. Thanks for the work you put into your videos. They are so helpful.
Could you tell me the amount of 404a freon I use in the medium size dryer? Harvestright did not put info on the labels on the refrigeration unit. Some info they took a marker too also! I cannot find the answer so far. Thanks.
This is what I received from HR last year. I hope it's the same to what you received: "Freon R410A pres. @ 70 degree room temp after unit has chilled down the low side pres 2-5 psi high side is about 250 or less psi there should be frost on the suction line near the access port if there is frost on the compressor there is too much freon and some should be bled out if the charge is correct the bottom center of the chamber will -55 degrees +/- 5 degrees "
Phil, you mentioned that the moisture sensor is on one of the shelves in the medium freeze dryer. Was it the 3rd shelf? Thanks for all your wonderful information!
The moisture in the food needs to be super rock hard or it will boil. Slowly controlling the sublimation by increasing the heat controls how much of a vacuum drop will happen. Water can sublimate at -10F, but I'm not sure at what minimum vacuum.
I call it "pausing". Here are the steps: 1. While the machine is running, open the drain valve. This will release some of the pressure against the check valve. 2. Turn off the pump at the pump's switch. Wait for the vacuum to release and open the door. You have about 15 minutes to rotate the trays, stir the food, etc. To restore the system, Close the door, close the valve, and turn on the pump. This video has more info: ua-cam.com/video/cEgkJ6euao0/v-deo.html
Phil, what's your experience been with freeze drying cycles ending at odd hours, like in the middle of the night? Would you just let the FD run until the next morning and handle it then? I'd love to hear your thoughts on this.
Under vacuum, the frozen water in the food, turns from a solid directly to vapor when heated. This is call sublimation. At 500 Mtorr the water boils immediately. The vapor "floats" around until it touches the chamber wall and then freezes. After the batch is complete the ice on the chamber wall melts and goes out the drain.
Shouldn't be a problem. If the cycle ends while you're out, the food might cool down. I keep my "Extra Dry Time" at 12:00 hours just in case it finishes at night or while at work.
Hard to say. It depends on what's in the tray. The greater the mass of food, the more heat is required to warm the food for sublimation. During the dry cycle, the heaters turn on basically when the vacuum is below 500 Mtorr (this depends on your software). As the pressure increases the heaters turn off. Your logs will show the temperatures and the time the heaters were turned on in seconds per minute. The temperature is also displayed on the screen. You can control the tray set-points from your screen.
Thank you so much for the detailed reply. Currently I don’t have this device . Before buying I want to understand the internal working. In the drying cycle when the heater is on when temperature reaches -40F, at that cycle the refrigeration cooling compressor is ON or OFF? What about final drying cycle. Heater, cooling compressor, vaccum pump all three are ON or heater and vaccum pump only ON?
The refrigeration is always on, and needs to be. The chamber wall is a "cold trap" for the sublimation vapor from the food. The heaters cycle on and off depending on the vacuum pressure inside. As the food "warms" up the ice flashes to vapor and freezes on the chamber wall. A pressure sensor monitors the the ups and downs. When no more change occurs, the food is dry and the cycle ends. The vacuum pump remains on until the end of the process.
@@Philat4800feet excellent explanation thank you. Now what I understood is, generally in the three cycle. First freeze cycle cooling compressor only is on for 12 hrs, Next drying cycle cooling compressor on, vaccum pump on, heater is on wrt pressure difference for 12 hrs. The final dry cycle is for 24 hrs .
Thank you for the explanation. I thought a regular freezer tank can be used, but I see the vacuum sealing needed in the process.
Been meaning to comment on this for a while. Thanks for this video.
Good, quick explanation of the process. It nice to have this video to steer viewers to when they ask for a simple, fairly complete, how-does-it work video.
(I would complain about the pressure sensor location vs temperature probe/thermistor location) 😁 But that doesn't change the function of the machine or how understandable the video is.
Glad it was helpful
This is excellent. Thank you so much...
Thank you.
Best explanation ever!!!
Glad you think so!
thank you for this explanation. @schoolreports sent me here when I asked for a basic non techy explanation. This definitely fit the bill. Would love a video that explain the presets under the customize button and why/if you would want to change them. Maybe it's already out there and I just haven't typed in the right words in the search bar? When watching videos of FD with the older firmware it's confusing to try to "translate" that into the newer firmware and understand exactly what I need to do. Thanks for the work you put into your videos. They are so helpful.
Try this:
ua-cam.com/video/N5vyMXjieUc/v-deo.html
@@Philat4800feet it says the video is private and I cannot view it
@@sanot8443 Don't know what to say. Visibility is marked Public.
Yea unfortunately sais its private, great videos tho, always well done @Philat4800feet
Could you tell me the amount of 404a freon I use in the medium size dryer? Harvestright did not put info on the labels on the refrigeration unit. Some info they took a marker too also! I cannot find the answer so far. Thanks.
This is what I received from HR last year. I hope it's the same to what you received:
"Freon R410A
pres. @ 70 degree room temp
after unit has chilled down the low side pres 2-5 psi
high side is about 250 or less psi
there should be frost on the suction line near the access port
if there is frost on the compressor there is too much freon and some should be bled out
if the charge is correct the bottom center of the chamber will -55 degrees +/- 5 degrees "
This was informative. Should I be concerned if only the front half of the chamber builds up ice? If not what’s the problem and solution?
Can you run a cycle successfully?
Phil, you mentioned that the moisture sensor is on one of the shelves in the medium freeze dryer. Was it the 3rd shelf? Thanks for all your wonderful information!
The proper name is a thermistor. It's a temperature sensitive resister. It appears as a "worm" under the heating pad.
Great information…so the “worm” is the under the 3rd shelf from the top?
good explanation
Thanks
I found the freon info on the harvestright site in information for refrigeration technicians. Thanks anyway
why does it get all the way down to -40F just to heat it back up? Can food sublimate under low pressure at like -10F?
The moisture in the food needs to be super rock hard or it will boil. Slowly controlling the sublimation by increasing the heat controls how much of a vacuum drop will happen.
Water can sublimate at -10F, but I'm not sure at what minimum vacuum.
How do you inspect the food for dryness without releasing the vacuum .. ??
The machine will not allow you to go back to drying once it’s been open?
I call it "pausing". Here are the steps:
1. While the machine is running, open the drain valve. This will release some of the pressure against the check valve.
2. Turn off the pump at the pump's switch. Wait for the vacuum to release and open the door. You have about 15 minutes to rotate the trays, stir the food, etc.
To restore the system, Close the door, close the valve, and turn on the pump.
This video has more info:
ua-cam.com/video/cEgkJ6euao0/v-deo.html
Phil, what's your experience been with freeze drying cycles ending at odd hours, like in the middle of the night? Would you just let the FD run until the next morning and handle it then? I'd love to hear your thoughts on this.
I keep my extended dry time at 12 hours for this reason. You can't over dry your food.
how does it knows that the food is really frozen? is there a sensor?
Frozen food around -20 degrees, won't give off any water vapor. any water vapor (sublimation) will be detected by the vacuum sensor.
hello Phil, how is the water vapor thrown out, can you explain in a little more detail, thanks
Under vacuum, the frozen water in the food, turns from a solid directly to vapor when heated. This is call sublimation. At 500 Mtorr the water boils immediately. The vapor "floats" around until it touches the chamber wall and then freezes. After the batch is complete the ice on the chamber wall melts and goes out the drain.
Hi Phil, is it safe to leave the house to run arrands while the freeze dryer is running
Shouldn't be a problem. If the cycle ends while you're out, the food might cool down. I keep my "Extra Dry Time" at 12:00 hours just in case it finishes at night or while at work.
what happens to the excess water, is it contained or deposit where it goes?
All water in the food/trays is sublimated and froze to the chamber wall. At defrost, the frozen water melts and runs into the drain.
What is the heating pad temperature range.?
Hard to say. It depends on what's in the tray. The greater the mass of food, the more heat is required to warm the food for sublimation. During the dry cycle, the heaters turn on basically when the vacuum is below 500 Mtorr (this depends on your software). As the pressure increases the heaters turn off. Your logs will show the temperatures and the time the heaters were turned on in seconds per minute. The temperature is also displayed on the screen. You can control the tray set-points from your screen.
Thank you so much for the detailed reply. Currently I don’t have this device . Before buying I want to understand the internal working. In the drying cycle when the heater is on when temperature reaches -40F, at that cycle the refrigeration cooling compressor is ON or OFF? What about final drying cycle. Heater, cooling compressor, vaccum pump all three are ON or heater and vaccum pump only ON?
The refrigeration is always on, and needs to be. The chamber wall is a "cold trap" for the sublimation vapor from the food. The heaters cycle on and off depending on the vacuum pressure inside. As the food "warms" up the ice flashes to vapor and freezes on the chamber wall. A pressure sensor monitors the the ups and downs. When no more change occurs, the food is dry and the cycle ends. The vacuum pump remains on until the end of the process.
@@Philat4800feet excellent explanation thank you. Now what I understood is, generally in the three cycle. First freeze cycle cooling compressor only is on for 12 hrs, Next drying cycle cooling compressor on, vaccum pump on, heater is on wrt pressure difference for 12 hrs. The final dry cycle is for 24 hrs .
MYfreeze dryer never went below -22 i call the company they only want to sell me a new one
At -22 degrees, can you still complete a cycle?