This will probably fall into the TLDR category, but it's the only review on the internet that I know of, so it's unique and will be on the search engines.
I finally settled on my main method for getting clean drinking water, which will work as long as I have electricity and a water supply (electricity is more of a problem where I live than water). Thanks to PeakOiler who got me started thinking about distillers, although I didn't go with a solar still for my primary one (I plan to still build one though).
My first abortive attempt was to use a dehumidifier to get water without municipal contaminants. I would then filter this atmospheric water with a Berkey filter to remove any airborne impurities. It worked OK, but I think there were too many atmospheric impurities which overwhelmed the filter. I would see small dust particles in my water, so I quit using it.
I chose not to use reverse osmosis as it doesn't seem to remove many organic compounds like pesticides, hormones and prescription drugs. I started researching distillers. Distillers should remove almost all of the impurities except whatever can evaporate or become volatile to its gaseous state at a temperature less than or equal to 100 degrees C, which isn't much. This distiller has a bleed valve for VOCs before the condenser which will remove the majority of them. In my research I found a company called Durastill which I'd never heard of. They appear to be one of only two or three electric distiller manufacturers that make residential and commercial distillers. They have been in business since 1980 and all their distillers are made in the USA. The most interesting thing, I thought, is that they do a sizable percentage of business with the federal government, especially foreign embassies and corporations. Every time I called they first asked me for my agency name or company name, and the embassy reference is listed on their website. I've searched the web and found NO reviews of Durastill distillers. As far as I know, what I'm writing is the only one in existence.
So I ordered a Durastill distiller and the drinking water (distilled product) tank. They have much bigger models but I got the model 30H and 4 gallon automated drinking-water tank. Their model numbers and their specs aren't very well-labeled at their distributors so it was slightly confusing about what exactly I wanted to order. The 30H and 30J aren't even listed on Durastill's website. The 30H is a distillation unit that has a 2.5-3 gallon reservoir. It will distill about 2 gallons of water per batch and it takes about 6 hours to do so. The 30H is a manual unit, versus the 30J which is the same unit but automatic. The difference is that you must manually add water to the reservoir of the 30H for distilling and the 30J will automatically draw water from an input line that you've connected to your under-the-sink plumbing automatically when the reservoir level gets low and stop drawing water when it's full. Both units will shut off the heating element and fan when the water level gets about 2" above the bottom of the tank so as not to burn up the heating element.
The 30H operates by heating the water in the tank, sending water vapor through the coiled condenser hose which has a fan blowing on it. The condenser hose has hundreds of fins which help to cool the hose and vapor faster with the help from the fan. The hose exits the bottom of the 30H for water to be collected. If you have a 4 gallon drinking water tank like I got, you connect a hose from the exiting condensing coil to an opening on the top of the tank. The tank holds 4 gallons and has a spout from which you can draw ready-to-drink water on the front. The tank also has a float attached to a switch that will cut off electricity to an outlet when the drinking water tank is full. It is intended that you plug the electrical cord from the distiller into the tank and leave the switches for the fan on. When the drinking water tank fills, it will turn off the distiller. When the distiller is out of water, it has a float to turn itself off. If you had a 30J automatic distiller, it would automatically fill the distiller when it got low on water. So the entire process can be completely automated to keep you a full reservoir of drinking water. I've run three batches so far and the automated functionality works very well.
You can check out the claimed purification standards here: http://www.durastill.com/learn_more_analysis.html
Notice that they spiked the water with impurities waaay higher than what you would get from your tap water. So it's still not an accurate test for what you would experience in real life, but it's a good indicator.
I decided to return my dehumidifier and keep my Berkey to use in conjunction with the Durastill. So I'm going to distill my water and any remaining impurities that are in the water will have to get run through the Berkey, which claims a 95%+ reduction in all impurities as well.
After running two batches, I inspected the distillation tank to see what was left in there after the water was removed. I was shocked and saw much more precipitate than I anticipated. There was a very fine coating of white silt on everything inside the distillation reservoir. It wouldn't come out with just spraying of the faucet head, I had to put a dish brush in there to dislodge it and coax it to the bottom so it would drain from the tank. I'd say that I am being generous by estimating at least a minimum of a teaspoon of impurities per gallon. There was a very noticeable bit of silt covering the walls and floor of the tank, much more than I was expecting.
This unit does use a decent amount of energy. The heating element is rated at 1000 watts, plus the fan (unknown watts). The manual says it produces 3100 BTUs of heat (or 1000 watts of heat, duh), so it could heat up a room, but I haven't noticed it to be severe yet. In the summer I may move it out to the garage or to an unused bedroom and close the door. I have not noticed any increase in humidity, it shoots right into the tank. Running this guy for 6 hours will produce about 2 gallons of water. That is a substantial amount of energy bill right there, at least $20/month in these parts. If you have a family, I would suggest getting an automatic 30J so you can keep the drinking tank full, and your electricity bill will be higher as you will possibly be producing 8+ gallons per day.
This unit looks like it will take very regular maintenance to keep from having calcic precipitates coat everything. The seller told me these units should last 10 years. I think it will last much longer if you take care of it and make sure calcium doesn't clog up everything. Durastill sells some acidic cleaner which is supposed to remove the lime build up, but I would imagine anything that is food safe and will not remove stainless steel coating will work.
Here are the pics (click): http://codemonkeyx.com/offsite/durastill_11.jpg
Unit from the left side. Note the upper unit is the distiller. The upper unit has vents on the left side for the fan blowing air across the condenser coil. On the right side of the upper unit you can see the sealed opening for feeding the distiller's reservoir. On the bottom is the 4 gallon reservoir where you draw drinking water. The top unit sits on the bottom unit freely and can be lifted off once the power plugs are disconnected.
Right side (click): http://codemonkeyx.com/offsite/durastill_22.jpg
On the right side you can see the distiller's drain valve for draining left-over refuse precipitate into the sink. The switch that operates the fan is on the right side, which is normally left on and operated automatically by the distiller's float and drinking water tank's float. The small round button on the front looks to be some sort of reset button for the heating element, but the manual didn't explain that at all. The heating element is directly behind the red button.
Inside the distiller reservoir (click): http://codemonkeyx.com/offsite/durastill_33.jpg
The heating element and the float which operates the shut-off functionality of the heating element and the fan when water level is too low.
Top-down shot of the condenser coil and fan in the distiller unit (click): http://codemonkeyx.com/offsite/durastill_44.jpg
This is inside the top distiller unit on the left side. You can see the condenser coil with the cooling fins. Beneath the condenser coil, you can see parts of the fan but it's hard to see. The vapor enters from the bottom right of this picture from the top of the unit and leaves, condensed, at the bottom of the unit on the upper left of this picture.
Shot through the crawl space between the units from the left: http://codemonkeyx.com/offsite/durastill_55.jpg
This is so you can see the connections between the units. On the left is a clear hose connecting the condensing hose from the top unit to the bottom tank. On the right in the foreground is a round float that is sitting on top the bottom tank. Once the float on the inside rises, it will raise the small paddle with a cut-out channel sitting on top in the middle of the float. You can see a small elbow-shaped wire sitting in this paddle-shaped pin on the float. Once this wire is raised, it triggers a switch in the electrical box in the rear ground on the right hand side. This box has an outlet cord for the lower tank to be plugged into the wall and receive power, as well as it's own receptacle so you can plug the top distiller into it. When the elbow shaped wire is raised by the float, the switch shuts off power to the top distiller. It works very well.
Shot through the crawl space between the units from the right: http://codemonkeyx.com/offsite/durastill_77.jpg
You can see the connection between the top unit's drain from the condenser coil and the input to the bottom tank on the left background. On the far right, you can see the electrical switch box which controls the power supply to the top distiller, controlled by the float in the middle foreground.
Right side crawl space. http://codemonkeyx.com/offsite/durastill_88.jpg
Left side is the distiller's drain for the refuse precipitate. Right side is the on-off switch box for the top distiller, controlled by the float on the bottom tank.
Back of the unit. http://codemonkeyx.com/offsite/durastill_99.jpg
In my opinion, this guy works very well. It definitely purifies water. I had no idea there was so much crap in it. Coupled with the Berkey, I think this will make exceedingly pure water. It seems to be very well made, I have no complaints with its construction. Spare parts are available when the fan and heating element wear out. The manual is rather old (it said 1985) and didn't explain everything about assembly. I still have no idea what the red button on the front really does. But if you take your time, you can figure it out. If you have large hands and forearms, it is very difficult to get your forearm inside the container to clean the back corners as the apertures are so small on the top. But it can be done with long-handled brushes if you're careful. Cleaning solvent (acid, basically) from Durastill should make cleaning this things a breeze if you make sure to clean the precipitate out of the distiller's tank at least weekly. I don't think anyone has ever posted detailed pics of these things before online, which is why I gave it a thorough review. If you are going to spend almost $1000 on one, you should know as much as possible about what you are ordering. It does seem to be a very well-made product and I would recommend it. I definitely can think with a clearer head during the day while I'm banging out code after drinking pure water for a few days.