I have a self installed open loop 3 ton Bard multistage heat pump. I dump the water into a ditch in front of the house that empties into a stream. The house is a 1970's 1700sqft ranch with a basement and is well insulated by me. So far I am extremely happy with the unit. Last winter it had no problem keeping my house at 71F while it was in the single digits outside. So far this summer I can easily keep the house at 74F when its in the mid 90's F outside. I have no doubt I could make it colder but 74F is fine. My most expensive monthly electric bill was $199 last winter. $66 was heat, $25 was hot water, the rest ($108) was the normal house. My summer bills are pretty cheap so far. I have not really noticed any increases, and the monthly bills are around $103 which is pretty normal for me. Install Procedure: I did a bunch of planning before I installed. I evaluated my house and did a bunch of manual J calculations to size the pump. My old furnace was a 100,000 BTU fuel oil which I calculated was way over sized. I looked at several other heat pump installs in my area to help get some opinions from real people. I calculated everything based on cooling capacity. I did not even consider the units heating capacity. I decided on 3 ton based on numbers and accurate measurements of my home. I used a free program called HEED: Home Energy Efficient Design I plugged in weather data for my area and input all my data. It took a good weekend to get it all in there and it seems to give me sensible numbers. I also did a bunch of reading about duct calculation and furnace install to make sure my house was setup correctly. I ended up adding a big cold air return in my basement to help with the humidity down there. I called DTE (Detroit Edison) and got hooked up with a planner and they came out and inspected my electrical service feeding the house. I wanted the cheaper heat pump rate and they told me my old 150amp service was not good enough. Well.. I went and got my electrical and mechanical permits ($150 each). I had Edison install 400 amp underground residential with dual electric meters. I did all my own electric work and had to pull the old meters off the house and upgrade my existing breaker box to 200 amp and install a 2nd 200 amp breaker box for the heat pump, well pump, hot water heater, and emergency heat. So yeah I now I have dual 200 amp service boxes in my house. They also pulled my old utility pole and installed a new one with a upgraded transformer. The county electrical inspector came out and approved my install and electrical upgrades. I ordered the heat pump and installed that over the next 4 weeks (on weekends) since I work a lot of hours. Edison came back out and inspected my electrical install and plugged in my new meters. The county mechanical inspector came out and approved the heat pump install. Seemed like a whole lot of inspectors nosing around but I guess that's how it goes. They were all easy to work with and had no problem with my install. The mechanical inspector was blown away that I installed the whole thing myself. He pointed out some improvements for the ducts but they were not required changes and off he went leaving his green approval sticker on the heat pump. That's about it. So far zero problems. The only thing I want to do is install some added water pressure tank capacity to cut down on the well pump cycle time. I'll do that this summer.