Anyone here have any experience with this product?

Thanks

Bill

I would not use a QT flow center.

They say that you don't need a flush cart to purge the system.

This not true. The pumps on a QT flow center do not have enough flow to purge a system completely.

What about a QT interests you?

Just looked like an interesting approach. I am re-arranging the "furniture" in my mechanical room and was looking to do away with my scratch built pump center and use a nice neat pre-assembled flow center like the QT. (I have other uses for the pumps so I thought I would upgrade what I have) I believe their answer to that issue is that the system will constantly purge air. Is there a specific reason you do not recommend the QT? Bill

Their claim of constantly purging air is bogus. Certainly any air that makes it back to the flow center will be purged. If you have a vertical loop field and you have air your system, the pump needs to have enough flow to push the air down 200+ feet before it can come back to the tank and be purged. Since loops are tied in parallel the water (under low flow from a flow center) will take the path of least resistance through the loops with no air and the loop with air will not be purged.


Is a QT less money than a regular flow center?

If you are going to change out your flow center which will let air into your system, I would purge the system with a high head high flow pump capable of pushing all the air out of your system. Then it doesn't really matter what kind of flow center you have.

If you have a horizontal system then purging is easier, but still very important. Any air left in the loop will seriously downgrade the heat transfer of the loop.

Regular flow centers have purge ports which make purging easy once the install is complete.

I see no advantage to a QT flow center. Their sales literature talks like this is the new standard for flow pumps. I have been installing systems for three years and have never used one and I never will since I see purging as critical. The QT people act like purging is automatic with their pump. I doesn't work that way. With a regular purge pump you can tell when all of the air out of the system. With a QT, you hook it up and hope that the small pump will push all of the air out.

Hope this helps. My only interest is in giving people info so that they can make informed decisions. Good luck

just my two cents, my geo installer uses a small insulated tank, kinda like the salt storage tanks for water softeners, a 1/3 or 1/2 hp grundfos SQ submersible pump. it is basically a open loop, the pump pumpes through my verticle loop, then the heat pump, then the return line dumps back into the tank. the level in the tank is above the discharge of the return line so there is no bubbles. this basically self purges. my SQ is a 1/2 hp, it draws 5amps @ 120V. this setup might not look pretty like the QT but it is reliable like a claw hammer.

Sorry, but I need to speak on this. If you have a verticle system with several wells in parallel and there is a large air bubble in one of the loops, this bubble does not want to go down the loop. It will sit there at the top of the loop and block that loop. It renders this loop inoperable. A 1/3 or 1/2 hp pump does not have enough pressure and flow to force that air bubble down several hundred feet so that it can be purged from the system. When a company markets a 1/3 hp flow center as self purging they are foisting a lie on the consumer. Consumers who don't know any better and want to do it themselves get sucked into the lie.

One of these little pumps might be self purging on a horizontal system, but I wouldn't count on it. On a parallel system if one loop has air, the water will flow down the loops with out air.

I can see how they might work after the system has been purged with a high pressure high flow pump. Even then there are problems with these pumps. There is very little head pressure on the pump which can cause cavitation. Then the water is constantly taking on oxygen which will cause the impeller on the pump to rust away.

I don't make any money by selling pumps. My only interest is in helping people make informed decisions.

Getting loops in the ground is very costly. Any loop not properly purged just sits there adding nothing to your heat pump system. What a shame to lose a loop because of trapped air.

Sorry to rant about this, but geothermal is my passion.

just curiosity, how much is a QT worth? the above mentioned set up that i have in operation cost about $600. geodean, i see the problem you present with a air bubble in a verticle loop, i have a verticle loop, 10 holes around 90 feet deep, not sure of the exact configuration of parallel and series. i am pretty sure i dont have a air lock, my driller filled each individual loop with water after they grouted them to check for obvious leaks, all was ok and they left the loops full. what if i reversed the flow of my loop? as long as i make sure i dont get air in the hoses when i switch them, this should purge that possible bubble right? is there anyway to calculate if the loop is performing as it should, just by measuring temps?

hedgehog, reversing the flow would be a good idea. As long as you can keep air out of the lines. There is only one way that I know of to check and see it you system is free of air.

A regular purge pumps out of a tank. So you close the discharge valve so that the pump pressurizes the loop. You watch the level of the water in the tank. If it drops more that an inch or two, then you know you have still have air since air can be compressed but water cannot.

Yes this is all we use, never had any issues and very simple to install, feel free to call me if you any questions 1-800-360-1569 Jason I.W.A.E. http://ingramswaterandair.com

I second Dewayne's rant. The only way to move air out of a system is to overcome its buoyancy with velocity, and the only way to get sufficient velocity simultaneously in multiple parallel paths is with a powerful pump, far in excess of a typical circ pump.

Manufacturers of atmospheric pressure flow centers generally don't suggest that it will purge a system; though marketing companies do. If you flush the system correctly any flow center will work.
The real problem is the suggestion that you don't need to do the work.
There will be lots of geo DIY targeting marketing schemes. Buyer beware. Engineers don't build cars or transmissions or microwaves, average Joe's (no pun intended) do. Curiously, building these things yourself is not likely to save you time or money.
j

The method geodean uses for  checking for any air in the system is excellent.

Wouldn't surprise me if there are quite a few people who have a vertical loop or two that is "missing in action".

Had a kinked tube from a cave in recently discovered exactly as Dewayne describes (nice catch Mike).
It would suprise me if you had a lot of systems with air trapped in them. One thing they'd all have in common is poor performance.

Hi Dewayne,

Just my two cents, I have a two pump QT running for a 1.5 years now with no problems.  

I agree with you on some of the marketing hype regarding purging.  The proper installation specification to do purging according to B&D Mfg is to header up all your loops inside with two ball valves on each loop.  To purge ,you using the ball valves to isolate pump flow to each individual loop and purge each loop one at a time.  For 3/4" HDPE loops, you should have more than the 4.2 gpm flow (2' per second) require to purge a loop.  I can see possible problems as you say when loops are using 1" or 1.25" HDPE pipe in vertical bore application.

I my case my loops are header up outside and I installed two 3-way valves at the QT to hook up the purge cart.  I did talk to a person who installed a QT as described by mfg to a 5 x 600' horizontal slinky loop and it purged with out any problems.

Is the purging the only issue you have with the QT?   I like the fact that it is easy to add/check antifreeze, check pump flow, check level.
  
Bob G.

Hi Bob,

Good to hear from you. I guess purging and price are the two problems I see with QT's. Glad yours is working well.

Dewayne,

Would you agree if some one was using QT with 1" HDPE pipe there may be problems purging with a 26-99 pump?

Oh,

I also agree on price if paying list price.

One suggestion...If you ever need the unit serviced the flow center needs to be moved away from the unit.

Bergy

If each loop was valved inside the building, it could be done.  Otherwise, I doubt it

Can't see any advantage of multiple holes in a foundation.
J