The newer updated dryers are more efficient with shorter run times and updated firmware.
I bought my large Harvest Right dryer in December 2018 and have been running it almost 24/7 since. I have processed numerus types of foods and almost a years supply of food. Meats raw and cooked, dairy, vegetables, fruits, eggs, whole meals for home made MRE's even ice cream. A large dryer can process over 2000 pounds of food a year and will pay for it's self in less than a year when compared to commercially packaged freeze dried foods. Shelf stable foods that last up to 30 years when stored properly. Freeze dried foods retain 95% to 97% of the food flavor, nutrients, and texture.
The customer service at Harvest Right is top notch and eager to help with any issue that might come up.
As a prepper, this has been the best investment I have made and saves me hundreds of dollars on freeze dried foods. Crop losses and food shortages are becoming more frequent and will soon rise to crisis levels. Having a stock of foods that I can rely on in the future gives me peace of mind that I can feed my family in the hard times to come.
I recently ran across a blog that has done a wonderful cost break down on all 3 sizes of Harvest Right home freeze dryers. [omitted] The large unit is 25% more efficient than the medium and the medium is 40% more efficient than the small unit. What blew me away was that the large unit can process more food per batch than the medium and the small units combined.
I also invested in the oil less vacuum pump. In my opinion it worth the extra $1300 No oil mess to deal with. No risk of oil contamination on the foods. (food grade oil) No oil filtering after each batch. No pump tear down for cleaning after 10 batches. And it runs quieter.
I highly recommend this method of food preservation. One tip - these machines are designed to operate in temperatures between 35 and 85 degrees F. Because I have mine in my garage and summer temps can reach 120+ I had to design and build an air circulation system to pass air from the house through the machine just to keep it at or below 85 deg. Unless your prepared to do the same or just not use it in the summer, I don't recommend having it in your garage.