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  • #31
    Originally posted by Sunking View Post
    Just got over beating prostate cancer. Did you ever hear me complain?
    I am Happy Happy to just be alive and kicking your butt.
    ROFLMAO.... yeah, figured as much. Maybe most who have less experience with deep down communications with others don't understand someone like you. Might help that I'm familiar with Texass attitude (also previous ordained minister familiar with counseling) but I appreciate your snarky attitude and enjoy the posts responding.... Those with strength of character persist in search of knowledge, those weaker leave with their self inflicted frustrations.
    Lots of thorns in life's bed of roses. Some people go ouch and turn their backs, others say no prob, get closer and appreciate.
    Keep up the good work, spreading your excellent entertainment ...and knowledge.

    Comment


    • #32
      First off, I'm not in the GSHP business.

      You need to look at the numbers very closely. Remember that in Tx our groundwater temps stay at a constant 67-72* year round, versus air temps that fluctuate 20-30* in one 24-hr period. The SEER rating can be very deceiving. S in EER is for Seasonal. When the temp outside is 90-100*F the GSHP will be much more efficient than the ASHP which is rejecting the heat into the same 90-100* air temps. The GSHP is still using the same 67-72* medium, making it's EER much, much higher than the ASHP at that performance point. When outside temps are milder, say 80-90*F, the disparity is not quite so wide.

      That being said, I looked at the math one time. Even having access to free drilling it would not save enough money over 15 years even for me to do it. It would be neat and I think it would give great performance, but the match just doesn't add up for a hot climate, especially one that does not see cold wintertime temps like we do in S. Texas.

      Good luck.

      Comment


      • #33
        Two things I believe I have gleaned from this thread.
        1 the OP has a natural gas furnace so in reality switching to gshp the economics should be to compare BTU costs for heating and not just COP.
        2 even with electric back up with low energy costs as in Texas the break even point could be very long.
        NABCEP certified Technical Sales Professional

        [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

        [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

        [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

        Comment


        • #34
          Originally posted by Texas Wellman View Post
          That being said, I looked at the math one time. Even having access to free drilling it would not save enough money over 15 years even for me to do it. It would be neat and I think it would give great performance, but the match just doesn't add up for a hot climate, especially one that does not see cold wintertime temps like we do in S. Texas.
          Well said and the point we have been trying convey, the payback is not there.

          Even if you have an older ASHP you can dramatically increase its efficiency by doing two simple things.

          1 is put the outside unit in the shade with good air circulation.
          2. Use a misting system to lower the ambient temp. Newer ASHP and window shakers use condensation and the condenser fan motors to splash water onto the condensing coils to remove more heat than air alone.
          MSEE, PE

          Comment


          • #35
            Originally posted by Sunking View Post
            Use a misting system to lower the ambient temp. Newer ASHP and window shakers use condensation and the condenser fan motors to splash water onto the condensing coils to remove more heat than air alone.
            You are right, shade can make a big difference.

            I once lived at a place that I just could not get cool on the hotter days. So I installed misters around the top outside of the condensing coils. It worked, but after a while, I could see that the coils were getting mineral deposits on them. So I discontinued the use of the misters. However, I believe it would work if one took the condensation water from inside and pumped it outside to the misters.

            Comment


            • #36
              Naptown, you are correct. I have natural gas, and use it for hot water, furnace and the clothes dryer. So, I'm really mostly concerned with cooling. Funny how the near mention of GSHP makes everyone think of heating. It also works for cooling. A ground temperature chart I found shows my location at a constant 68 degrees.

              So is there any kind of consensus about the most efficient type of ASHP? I have started to look at the mini-split ductless heat pumps. They seem to be the highest efficiency, but it looks like the cost goes up quickly with multiple heads.

              Comment


              • #37
                SunKing, did you have something specific in mind when you said: "A ASHP SEER runs from 13 to about 25, COP from 3.5 to 4.7 or so"?

                Comment


                • #38
                  Have you seen this link: http://welserver.com/WEL0043/

                  I'm so impressed. I would love to see how he collects all this data real time.

                  Comment


                  • #39
                    Originally posted by t5800512 View Post
                    Naptown, you are correct. I have natural gas, and use it for hot water, furnace and the clothes dryer. So, I'm really mostly concerned with cooling. Funny how the near mention of GSHP makes everyone think of heating. It also works for cooling. A ground temperature chart I found shows my location at a constant 68 degrees.

                    So is there any kind of consensus about the most efficient type of ASHP? I have started to look at the mini-split ductless heat pumps. They seem to be the highest efficiency, but it looks like the cost goes up quickly with multiple heads.
                    Well here's a potential issue in a mostly cooling application
                    Depending on whether the aquifer is moving and soil type and water content around the well if you are using it for 80% cooling mode the temperatures will start to rise in the closed loop. The big jump in COP comes when the unit is changed over from heat to cool lets say but the reverse is also true.
                    You have cooled down an area around the well during the heating season so the ground around the well is very cold. Switch to cooling and this works in your favor for a while until you heat up the surrounding area to the point that it is now hotter than the ambient air temperatures. I have seen this in Maryland in August. Where loop temperatures are over 100 degrees.
                    In your case or any case where heating or cooling Is dominant the COP Is reduced.
                    An aquifer that has some flow to it to disburse the heat and cold is preferable. When I did these in the 70's we used open loop and set supply and dispersion wells far apart into the same aquifer. Thus we were disbursing heat or cold over a much larger area than can be achieved with a single bore
                    NABCEP certified Technical Sales Professional

                    [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

                    [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

                    [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

                    Comment


                    • #40
                      Found it. For only $555, you can to it too:

                      http://welserver.com/store.htm

                      Comment


                      • #41
                        The gentlemans name is Bill and he has replied to your thread at Green Building Talk. a0128958 is his member name.

                        Chris

                        Comment


                        • #42
                          Hey Naptown, thank you for the reply

                          I have been reading about the long term buildup of heat or cold in the ground. It sounds it can take years to build up and eventually it lower the efficiency of a GSHP system. I was just talking to a driller about it. His take was that it is really only a problem when the length of the ground loops are lessened to save on installation costs. He said that four loops at 300 feet each should be sufficient in my area.

                          My take on this is that I would probably want to use the GSHP for heating as well as cooling. It may still be nice to have NG heat for colder days.

                          Comment


                          • #43
                            Hey Chris, thank you for sharing the link in the first place. And again for letting me know about Bill. Now let me go see what Bill has to say.

                            Comment


                            • #44
                              Originally posted by t5800512 View Post
                              I once lived at a place that I just could not get cool on the hotter days. So I installed misters around the top outside of the condensing coils. It worked, but after a while, I could see that the coils were getting mineral deposits on them.
                              Bingo and that is why new units use condensation water.
                              MSEE, PE

                              Comment


                              • #45
                                Originally posted by t5800512 View Post
                                SunKing, did you have something specific in mind when you said: "A ASHP SEER runs from 13 to about 25, COP from 3.5 to 4.7 or so"?
                                It is just the gauntlet of ranges you find among all the manufactures. Look at American Standard units. AS is the best made. Second choice is Trane.
                                MSEE, PE

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