Why a Solenoid-Valve is a Deal-Breaker in FD. And how it can save you 40% of Energy.

Generally a Home-Freeze Dryer has 3 important Components:
- The Vacuum-Pump (~360W - 400W)
- The Cold-Trap (~600 W)
- The Heating Shelves (~500W)

These three Components plus Time, are used to get "Things dry". Regularly, the Vacuum Pump runs all the time during "Drying Stage".

From these, the Vacuum-Pump is the Component that makes the most noise, and also produces the most Heat (welcome in the winter, but not in the summer).

Now if we could Freeze-Dry and use the Pump only for a few minutes, we could save not only 40% Energy, but also have less moisture in the Oil and have much less noise and Heat in the Environment. Is it possible?
YES, it is.

And in this Video I show you HOW you can do that using a Solenoid-Valve that is between the Pump and the Freeze-Dryer.

There is one Thing I have to add. Doing this, you are possibly left with "Manual Mode". Neither "Automatic Mode" and also not "Program Mode" support the "pump-Less" Usage of the Freeze-Dryer.

WHY IS THAT?
In earlier Times electricity was cheap and not a question to save it. By today - at least in Germany - things have changed. Power-Saving is for anybody a issue.

SO WHY did they built the Solenoid Valve in then?
The Solenoid Valve was not built in for Power Saving, it was just built in to prevent Oil getting from the Pump into the Cold-Trap. Which is a totaly different Issue.

HOW can I save up to 40% Energy?
Assume we have Pre-Froozen Material, already loaded.
So I switch the Freeze Dryer ON. Then ...

1. I set the Pre-Freezing Time to 6000 - so we always stay in the Pre-Freezing.

2. Manually set the Shelve Heater to -15 degree (Starting Temp).

3. Wait until the Cold-Trap has ~-30 Degree Celsius. Then start the Vacuum-Pump and let it run until the Vacuum stops moving for ~10 Seconds. This means we are running in a "Moisture Wall".
At the same time we normally see that the Cold-Trap increases Temperature due to the Moisture condensing.

4. Then I stop the Pump. And just let it OFF. For 1,2,3 hours. Depending on Material, and development of Cold-Trap Temperature. If we reach -31 Celsius in the Cold-Trap again, then i start the Pump again and let it run for 1 Minute.

5. Often the Pump will then run directly to about 40 Pa and thats nearly the maximum we can get here.
In this case i stop the Pump again. And then i can just let the process run alone for several hours, even a full night.

6. Depending on the Goods i will then increase the shelve Temperature slowly or faster.
And then at this chance always run the Pump for 1 minute.

7. When i see that the Cold-Trap has reached its limits (~ 2.5 liters of Moisture) then i will take out the nearly full dry material and put it into Plastic foil. It will then wether get back into the freezer or just wait on top of the Freeze-Dryer until the Cold-Trap is completely Ice-Free.

7. Now i re-start the process again knowing that now there is just a bit moisture left. And this point there is another trick which enables you to see directly while the stuff is drying - if its dry or not. This point is an topic for another video.