I have been

I have been using one on my 4-ton system for a year now with out any problems. Unless you are manifolding your loops inside with individual ball valve on each loop, you may want install two three-way valves for flushing and purging. The QT is also a easy to hook up a temporary flowmeter to measure flow.

Bob G.

We have been supplying and installing these flow centers for several years with great success. The aspect we like best is the fact that it allows for expansion and contraction of fluid and pipe with changes in temp. This translates into many less call backs for reflushing the loop like in pressuized systems. We installed over 400 loops last year and even a small percentage of call backs soon add up.

Thanks for the feedback guys.

The company says that the QT eliminates the need for purging. I was a little suspicious of this claim. Do you folks feel that that claim is realistic? Do you have the two pump or one pump model?

BTW, I'm thinking of a 2500 ft horizontal loop (not vertical), give or take.

This was discussed a little over a year ago here.  See http://www.greenbuildingtalk.com/Forums/tabid/53/forumid/13/postid/30533/view/topic/Default.aspx .

Best regards,

Bill

We always purge the systems.  The QT will purge your loop if you have time to watch it, but never let it run dry or you may be replacing pumps!  We have a method of bypassing the flow center and purging the furnace and loop system prior to startup.  Because the small amount of residual air left in the loop system during the purge process will be taken care of by the flow center while running, we only have to purge for about 15 minutes versus an hour or more for pressurized systems. 

Another option for using the flow center for flushing is to bring all loop circuits into the building, build an indoor manifold with circuit valves, then isolate individual circuits while the pumps circulate and you keep the canister full of water.  This works great if you don't mind punching as many as 12 holes in your basement wall for a 6 ton furnace.  We manifold all jobs underground with only supply and return lines going to the flow center.

We install one and two pump QT flow centers as well as 3 and 4 pump multi-zone QT units.  Our supplier has a web site.  Contact me by email and I'll give it to you.

I was going to manifold the system outside the house (in FL here no freeze) , run the one supply and one return line into the house and purge each loop individually with the QT. Sound feasible?

If you can isolate each loop the flow center should be able to handle it. Having the option to manifold outside and still have access is a big benefit for you in FL not an option in OH

Can you reccommend a better, and maybe cheaper, way?

I built my own open "flow center" similar to a QT. Better? Maybe - mine has slightly more volume and allowed me to fit it exactly to the space I had. Cheaper? Surprisingly when all was said and done I didn't save much, even figuring my labor for free. I used 6" PVC and those fittings are expensive. If I was doing it over I'd probably just buy one.