(message removed and reposted since I posted in wrong sub-forum and also because this thread took another direction)
Hi, I am converting my open loop to a closed loop as we speak. I have a 4 ton waterfurnace that has been operating as open loop for the past 4 years. Due to very poor water conditions that have been progressively getting worse I am switching to vertical closed loop. So tired of changing filters every week an worrying about water flow. I would suggest to make sure you have the ability to go to closed loop. ( ie space and funds) For me it would have been easier to have the cost of the loop put in my mortgage. Cheers, Joe
Sorry to hear about that, Joe. Wouldn't water treatment be less expensive? What's your main contaminant? I'm sure you realize you'll take a serious efficiency hit if you switch to closed loop. We're just doing preliminary costing now. Getting a comprehensive water test is always the first step before moving forward with open loop. If necessary, the project does have space for as many closed loop wells as may required to handle the load.
Hi, I would say the primary contaminate is fine silt,mud, and I'm sure there is some irony bacteria in there too. When we first fired the geo up I only hat to change the 50 micron filter once every 2 months. It then progressively got to the point I was changing it monthly, then weekly. I then noticed a drop in water pressure from the well when the geo was running, and I have a constant pressure variable speed pump. When I pulled the pump out of the well it was restricted so much with silt, mud only a pencil stream was able to enter. As far as efficiency, I am told it depends on the ewt. Where open loop is constant there are times in the year that closed loop is more efficient( fall, spring/summer). when averaged out they can be the same. However, I will know the truth after my first year on closed loop. I have a water treatment system on the drinking side of the house. I don't think I could treat the million or so gallons of water each year I would use cost effectively. Plus the problem is now at the pump before it ever reaches the house. Cheers, Joe
Joe, the key is to stop sediment from being ingested by your pump. I had a variable speed pump on the potable well for my previous home. Although it had many advantages, it had almost zero torque and would even minor sediment would cause it to lock up (my water was very clean except for fine, silty sediment). After 3rd replacement, I learned about pump filters (duh!). A pump filter should greatly extend the life of your 50 micron filter (I recommend a flow rate monitor so you don't have to continually check the filter). A backwash filtration system can make your filter last even longer. Not cheap, but small change compared to installing closed loop. Injection systems are available to treat iron bacteria, although post processing may be required to comply with discharge water regs (I'm at the limit of my knowledge on this point). Even with a pump filter, I would advise against variable speed pumps for open loop geo. I would look at a constant speed ECM pump (same efficiency as variable). Less expensive and lasts longer. The main reason I installed a variable pump was to (almost) eliminate the pressure hysteresis required to protect a conventional pump from short cycling. With the variable pump, the cut-in / cut-out pressure differential was fixed at 2 PSI. Pressure hysteresis isn't an issue for a geo well. I think the reason so many open loop systems have been abandoned over the years is a lack of understanding by residential geo dealers about water treatment options. If they can sell a closed loop, that's more income and less headaches. However, the homeowner pays the price up front, and over the life of the system in lower efficiency. Take a look at the open vs closed loop AHRI ratings for your system. You are mistaken about water temps averaging out. Perhaps early in the heating or cooling season your ewt may be slightly higher (or lower) with closed loop than with open loop, but it will be *substantially* more favorable for the bulk of season. Much depends on your soil conductivity. If you didn't have a soils analysis done (at various depths) when you drilled your well, then you're throwing the dice with closed loop.
Opposite OBS, Likely the opposite around here. Reason why open loop systems were put in was because installers new nothing about loop design. It was easier to just spec a well and walk away. Plus in our lithography, you need to be looking at fairly large systems Before open loop starts winning the capital cost battle.
OBS, Can you post me a link to a filter system that goes on the submersible pump? I have never heard of these are they self cleaning? The only filter systems I have seen are after the submersible pump. In my case the pump it self is being restricted. I will still be using my primary well for domestic uses after the geo is disconnected and thought it might be worth looking at. Thanks for the info. First 300' well drilled and loop installed, drilling the second. If the electric bill stays with in a couple of hundred bucks from last year I will be pleased. Thanks, Joe
