[ Read Responses | Return to the Index ]
[ ]

Posted by Bob on Saturday, 23 August 2008, at 10:28 p.m.,
in response to Re: WEL and Watt node, posted by Dewayne

>> It looks like you have 2000' of slinky pipe in 400' of trench on a 4 ton system.

You are correct. 36" pitch slinky. 5 feet of pipe per 1 foot of trench.

>>On your graphs what is the difference between loop in,loop out and EWT, LWT? Where are you tracking with loop1, loop2, loop3, loop4 and where are getting the temps?

The first column is the ground loop sensors. Did not have the heart backfilling where I header up the loops so I have a 36" PE drainage pipe giving me access to header manifolds. My LoopIn/Out sensors are attached to the 1-1/4 HDPE about 12" from the header manifold and Loop1/2/3/4 are attached on each of the loop returns. My EWT/LWT sensors are located in the GSHP attached about 12" from HEX.

One of the things I want to measure was each loop return temp since my ground loop is layed out in an 'L' pattern. Loop1 is 100' trench at 7' depth and Loop4 has a 40' section running at 4' depth over a granite rock ledge.

>>Have you been through a heating cycle yet? How cold did your EWT get?

My system came online on Feb 11 this year. I back filled the loop field in January when it was 20F outside. Here is some of the first month readings from end of day WEL screen print outs.

Date Run OA Lin L1 L2 L3 L4 EWT LWT
---- ---- -- ---- ---- ---- ---- ---- ---- ----
2/11 13.8 31 33.0 36.7 36.3 36.4 36.8 37.8 32.5
2/14 9.1 36 34.2 37.5 37.4 37.3 37.7 38.7 33.3
2/15 9.2 46 36.3 40.0 39.3 39.2 39.7 40.2 35.0
2/16 6.8 33 35.0 38.5 38.1 37.8 38.6 39.7 34.5
2/19 10.3 33 35.3 38.7 38.5 38.3 38.8 39.9 34.6
2/21 14.4 30 30.2 33.7 33.4 33.8 33.9 35.1 29.7
2/23 4.7 37 33.3 37.9 37.4 37.3 37.5 38.4 31.4

(you may have to copy/paste into Notepad using Courier font)

These reading were taken just before midnight with the system running. Remember that these sensor have a tolerance +- 1 degree F. As Philp had suggested, I calibrated the loop sensors and EWT/LWT for a week inside a cooler in the basement by tweaking the WEL's device offset value. After this process, I would say the temperature values should be within a 1/2 degree with this group of sensor.

>> It will be interesting to compare data. I hope to use the data in future loop designs.

This is my first geo system and I want to get to know every thing about this technology inside and out. This will greatly assist in troubleshooting any problems in the future.

>>Sorry for all of the question, I am very interested in learning.
This is great to be able to share ideas and info.

No problem, this is a new hobby for me and possible a career change.
On Greenbuilding, nice job nailing Linda form Austin problem.

Question: Who was your IGSHPA instructer? What was suggested EWT design temperature?

Out here in Virginia the GSHP system have to compete against the ASHP systems. Very hard sell. Last year, drillers were getting $7-$10 per foot.

© 2000-2008, Phil and Lisa's relaxed lifestyle home. An exercise in Energy Smart, Not So Big living. www.OurCoolHouse.com - Ideas@OurCoolHouse.com

	Web OurCoolHouse.com

This site is all about building a cool, energy efficient house, that makes maximum use of earth sheltered design, passive solar heating and cooling, geothermal exchange energy management, and right sizing of the house for it's designated use. The home's placement is on a south-facing hillside in Deep Creek Lake, Maryland. This site describes the design process, the technologies used and the expected results. We also have a comprehensive Links Page for anyone who is also interested in designing a similar project.