I'm looking to have 4 x  1" vertical loops. I need to connect them inside the house to a manifold so that I use a QT Flow center. That's 8 holes. I was wondering if there is any issue connecting 3/4" pipe to the loops and bringing that into the house. I'm concerned if the reduction in pipe size affects things. It seems 1" loops are the norm around here. From what I read a Pro would connect all the loops together with 1 1/4" pipe outside, which kinda makes sense until I look at the Geo units, and they actually have 1" fittings, so why the 1 1/4" pipe?

Thanks

Posted By jpr321 on 26 Jun 2012 02:51 PM
I'm looking to have 4 x  1" vertical loops. I need to connect them inside the house to a manifold so that I use a QT Flow center. That's 8 holes. I was wondering if there is any issue connecting 3/4" pipe to the loops and bringing that into the house. I'm concerned if the reduction in pipe size affects things. It seems 1" loops are the norm around here. From what I read a Pro would connect all the loops together with 1 1/4" pipe outside, which kinda makes sense until I look at the Geo units, and they actually have 1" fittings, so why the 1 1/4" pipe?

Thanks

You may want to consider some alternatives:

Connect your 4 x 1" vertical loops to an appropriately sized and constructed manifold that's outside the structure.  Now you only need 2 holes through the structure.

Replace the higher cost associated with an inside fancy flow center by instead installing purge ports outside and pump motor(s) inside.

Locate the purge ports after the manifold and before the structure, situated such that a purge cart/pump can easily be connected when needed.  Use purge ports made of the same HDPE material as the pipe to avoid corrosion problems.  This will avoid air infiltration to the loop problems that will otherwise develop due to non-HDPE purge port corrosion.

Put the pump motor(s) inside close to the GSHP unit(s).  If using 2 motors for one unit, install them both close to the unit in a push/pull configuration.

Use larger than 1" pipe from the outside manifold, through the purge ports, and to the inside pump motor(s).  Size the pipe to accomodate water volume from all 4 x 1" pipes, with appropriate friction loss.  Purge port size will be whatever this larger pipe size is, BTW.

At the pump motor(s), reduce the pipe size down to whatever the motor requires, using an appropriate fitting.  And if there's no motor at the leaving water pipe at the GSHP unit, increase at the unit back to the appropriate pipe size again with an appropriate fitting.

Best regards,

Bill

The purpose of the 4 1" loops being tied into a 1 1/4" header system is to balance out the flow between the loops. Without a balanced flow your not utilizing your loop field to its max potential.

The purpose for us to header outside is to only drill 2 holes instead of 8 or more, and not to use shut off valves.
The purge ports should only be on the inside, since there might be occasions where air gets introduced again into the loop, and you need access to the purge ports. You also do not want to burry anything subject to corrosion, only PE material, unless you are building an outside vault.


None pressurized flowcenters are not fancy, nor are they expensive, and they help keeping the air out of the loop, besides giving you access.
If you are a DIY, you should not header outside since you are unlikely have a purge cart.
You need to control every loop with shut off valves to purge all the air out with the flowcenter.
What kind of unit (heat pump) do you want to put in, and what kind of flowcenter? 1 or 2 pumps, and what kind of pumps?

Posted By docjenser on 28 Jun 2012 12:41 PM
... The purge ports should only be on the inside, since there might be occasions where air gets introduced again into the loop, and you need access to the purge ports. You also do not want to burry anything subject to corrosion, only PE material, unless you are building an outside vault.

Good points.  Thanks.  I edited my above suggestions to align with your comments here.

Best regards,

Bill