Had a similar thought, but the other unit lists a different flow rate.

Ground temp seems about what I'd expect, reasons EWT and LWT delta T would be low include poor airflow, low refrigerant, gpm flow higher than 12.....
Might want to first verify your test methods and equipment and call for help if results are the same.
Unit will protect itself with lock out if it gets too cold.
Good night (morning),
J

to get caught up on yoru questions I have one flow center plumbed with the heat pums in parallel. The flow center can produce a max of 22 GPM. The ES049 requires 12 GPM and the ES049 requires 8 GPM a total of 20 GPM still below what is availiable. the nlet andoutlet of the flow center are 1.25" pipe then imediately after the pumps pushing to the heat pumps the pipe is reduced to 1" is this a possible problem? shoule i look at increasing this? The pipes to my geothermal field are 1.25"to the manifolds then there are 6 trenches with 800 ft of 1" slinky pipe. The initial install had two Grundfos 26-99F pumps pushing to the ES049 and one 26-99F pump pushing to the WP036. I was told that one pump pushing to the heat pump and one pump pulling from the heat pump may resolve my issue of one unit robbign the other unit of flow. SO i made this change and split the pumps with no noticable improvement. with the pumps split i was gettign about 10.5 GPM since i am not using the water to water unit i took that pump and added it to the air handler and i am now getting 12.5 GPM. So do i increase the pipe from the flow center to the heat pumps to 1.25" or do i use two Grundfos 26-116F pumps on the airhandler and two 26-99F pumps on the water to water?

How are you getting rid of the air as you move pumps around?
How about tests on your test equip.?
J

the flow center is an open loop system. GT Flow Center by B & D manf. One of my fears with the low water temp was an airlock in the slinky pipes but you did not seem to think the EWT was an issue. The test equipment was just installed yesterday the flow meter is a paddle wheel flow meter calibrated 1/30/2009 and the temperature probe is a C&D Valve immersible probe that fits perfectly into the P/T Ports. i had the temp probes in a bucket of water for 2 days and there was a 0.2 difference between them.

i change air filters ever quarter so the current one has 40 days of use on it. Space Saver 2400 filter

ok,
but air could impact heat transfer much more on a small heat exchanger.
filter ok?
I'll tell you right now my gut hunch is low refrigerant, but I don't know what I forgot to ask or what you forgot to tell me (the shortcoming of remote diagnostics).
Any one else have a hunch?
J

i appreciate all yoru time and effort with my issues. Thank you for all you have done.
my question regarding low refrigerant is why does each unit run fine independently (until the EWT got below 35 F) then when run simultaneously do i have problems? the only thing the two units share is the flow center. The EWT does not seem like it bothers you so all that i see that is left is the Flow GPM.

What is the ideal EWT for maximum heating effeciency? What is the ideal EWT for maximum cooling effeciency?
What is the ideal delta T for EWT and LWT?
What is the ideal delta T for the RAT and SAT in heating? What is the ideal delta T for the RAT and SAT in cooling?

ok, you said units were piped in paralell, by that we mean not sharing loops or flow centers correct?

they share flow center and loops at the flow center there is a 1.25" port on the left that feeds the air handler ES049 (12 GPM required) on the right an 1.25" port that feeds the water to water WP036 (8 GPM required). I am sorry if i got that wrong

1) High

2) Low

3) 5-15

4) 20-30

5) 17-21

I realize the first two responses seem flip. That is because the answers are highly dependent on conditions specific to a given system.

3 Has a wide range - varies widely for closed vs open loop systems.

4+5 are approximations as well, but typical for many systems.

Ok, that changes things.
Which unit is upstream (first in the series).

there is no upstream on comes from the left side one comes from the right side the unit is the last unit on page one of (http://www.bdmfginc.com/prices.pdf) 2-1E-A-KFC-S.S. two pumps ont eh left for the ES049 and one pump ont he right for the WP036

ok, link is acting up but it looks like you have a multi zone flow center. both flow rates must be met at the same time or by priority, and loop field must be large enough.
Are units running at same time? Are flow requirements met if they do?
Low delta T's and frost are indicitive of low water flow among other things.
J

I'll touch base with you tomorrow pm
J

i was told that each 800 ft of slinky pipe was equivilent to 1 ton of heat/cooling as a rule of thumb. I was told that the air handler required 4 tons 3000 sf house and the water to water required 2 tons 1500 sf of basement/garage i have 6 @ 800 ft slinky pipe.
I have the water to water unit shut down and i stole the pump off of it since i view that as a luxury and the air handler as a necessity.

So the lower the delta T on the EWT and LWT does that correspond with lower delta T between RAT and SAT?

The flow requirement for the ES049 is 12 GPM indipendently with two UP26-99F i was producing 10.5 GPM
The flow requirement for the WP036 is 8 GPM indipendently with oneUP26-99F i was producing 5.5 GPM

I think that low flow will give you a higher delta T on EWT and LWT. You are taking more heat out of less water .