Virginia full retro install cost seems high?

Discussion in 'Quotes and Proposals' started by wildwolf, Apr 11, 2020.

  1. wildwolf

    wildwolf New Member

    Thanks for the info.

    Back to my geothermal installation, I think the system is coming along well. The 3 well loops (1.25" pipe) were all attached together via 1.5" pipe with T connectors and brought through basement wall. The lines were then routed up (2 90 degree joints) in wall to the drop ceiling area and then routed to the pumps (via some long connecting pipes & 3 more 90 degree joints), then split via connectors to both of the pump things mounted on the wall to feed each system. I think with a little more careful planning up front, they could have avoided 2 of the 90 degree bends. I mentioned that I wished it'd had not needed those last 2 bends (if they'd brought over the lines 3-4 more feet in drop ceiling, they could have avoided the additional bends), and the installer said he's had installs with "many more 90 degree turns than I have" and those systems worked great so he doesn't think I'll have any issues.

    They finish the tie-in today, start fill up tomorrow with the rest of the HVAC crew, and tomorrow starts the rest of the system installations. I hope they'll finish by Friday COB, but it will be tight now, I think.
     
  2. gsmith22

    gsmith22 Member

    I don't know the lengths involved, but would have expected 2" header pipe with a two system setup as flows for a 6 ton (total) system would be on the order of 20gpm. 20 gpm through a 1.5" pipe has a much bigger head loss vs. 2" pipe. There is another thread on here that I was responding too that had a really long run to the field and they used 1.25" header pipe. that one definitely needs 2" pipe (at the minimum). take a look at geo-flo's design calculators and search for multi-unit, distributed pumping system to input your system parameters and verify head loss with pipe sizes/pumps. Efficient water pumping is the holy grail of these systems. There isn't a penalty other than material costs for putting in larger pipe upfront. You will pay for higher pumping costs every month for the life of the system and thus reduce your system efficiency as a result. Not saying this is making the system unworkable or breaking the bank (don't know all the system parameters) but probably isn't as efficient as could be.

    Edit: found this table which will be approximate and certainly correct from order of magnitude perspective :
    www dot engineeringtoolbox dot com/pe-pipe-pressure-loss-d_619.html

    Notice how at 21gpm in 1.5" pipe there is 2.9ft of head loss per 100ft and at 2" pipe this value is 0.83ft of head loss per 100ft. At these max system flow rates, pumping requirements are way higher with 1.5" header pipe. Now this is at 68 deg F water and your loop will be a lot colder with some type of antifreeze so the absolute numbers will be higher. But I wanted to show how a seemingly small difference in pipe diameter at high flows can have a huge affect on system operation
     
    Last edited: Nov 11, 2020
  3. wildwolf

    wildwolf New Member

    May be 2. I’ll confirm tomorrow when they return.
     
  4. gsmith22

    gsmith22 Member

    nominal pipe size should be on the side of the pipe
     
  5. wildwolf

    wildwolf New Member

    It’s got a thick insulation sheath on all the inside line and all the outside line is already buried.
     
  6. wildwolf

    wildwolf New Member

    I emailed him. He replied that the line coming in is 1.5”.
     
  7. wildwolf

    wildwolf New Member

    Also, too late now. All the lines from wells to house/pumps finished today. They will tomorrow and start connecting the rest of the systems up. It’s 3 vertical wells at about 330’ deep each. They are all within 50’ of the house and maybe another 50 feet back to utility closet.
     
  8. gsmith22

    gsmith22 Member

    those are about the same lengths in/out to the field as mine. I have 3 - 400ft wells so I have more pressure loss in the vertical wells than you and I have a 3T and 4T unit so slightly more pressure loss through the heat exchangers as well as the overall system because my max flow will be higher with everything on. All those things should make my installation have more head loss compared to yours. I didn't see anywhere what flow centers are being used in your system. I'm guessing single speed units given the use of 3 and 5 series WF units. WF typically specs either a single UPS26-99, single UP26-116, dual26-99s, or dual 26-116s. The 26-99 pumps are more efficient than the 26-116 pumps so if you can get away with one 26-99 per heat pump you will have as efficient a system as you can get with fixed speed flow center pumps.

    What I wrote above about more energy use with 1.5" vs 2" header piping isn't correct for a single speed flow center pump (it would be for a variable speed flow center). With a single speed flow center, it operates at the pump's set speed using a fixed amount of power (variable speed can ramp up and down with unit speed causing power use to go up and down). What will change for a fixed speed pump is the resulting flow in the system - more flow in a system with lower head loss (2" header) and less flow in a system with higher head loss (1.5" header) for the same fixed speed pump. So with a 1.5" header, you should expect lower flow than if you had a 2" header. As long as whatever flow is produced meets the unit's flow needs, then none of this matters. geo-flow's design calculators would be where you could figure out the smallest pump size needed for your installed piping.

    Note, most installers and WF don't "design" any of this. Apparently water flow is Greek to them and they like to focus on unit efficiency. We pay for system efficiency so I would make water flow a priority. They like to throw power at the system so they don't get a callback (more power more flow so heat pump is happy) but that ends up costing you more on your electric bill forever. The key is to use only as much pump as you need to minimize power used to pump water around. WF sent a two pump flow center system for my 4T unit stating that was what their standard was. I politely told them to take out the second pump and put a plate over the flow center opening because I had used the geo-flo calculator to determine that I didn't need the second pump. Shockingly (not) the system works as predicted by the geo-flow calculator.
     
  9. wildwolf

    wildwolf New Member

    Geolink flow center FC2-GL on the 5 series and FC1-GL on the 3 series.
     
  10. SShaw

    SShaw Member

    You should have a pressure drop calculation done. I think you should be able to run each heat pump with a single-pump FC1 flow center, unless you have very long piping inside or something.
     
  11. gsmith22

    gsmith22 Member

    You got the WF "standard" like me. Fc2 has two 26-99 pumps and fc1 has one 26-99 pump. They are both the same flow center body that can use either 1 or 2 pumps with the fc1 just having a plate over the second pump opening. Geo-flo makes them for WF so using their calculator is easy. Multi-unit, distributed pumping is your system layout in their calculation page. I'd run a calc to see if you need the two pump flow center - I doubt it like SShaw says but check the math. Its easy to remove and put cover plate on now but more trouble once loop is full and pressurized. The 26-99 can be set to run at 1 of 3 fixed speeds using 150W in speed 1, 179W in speed 2, or 197W in speed 3.
     
  12. wildwolf

    wildwolf New Member

    They need to come back Monday to finish up. A snag here or there all week caused a bit of a delay in finishing. However, the basement series 3 system is up & running. Water from loop was 57.x degrees. They tested pressure from line going in and it was 39, line coming out was 31.
    Not sure how to convert that to GPM, or if I need to. It was putting out 95°F air at the furnace. I checked a couple vents and was getting about 78-83° out of them. Could have been more accurate, as I was just using a hand-held laser temp thing. The thermostat line from the old furnace is old, so they couldn't mount it there yet. They didn't bring additional line, but will do so on Monday. The upstairs unit had an issue with electrical wire they ran to attic, so they'll be running a new line I think is what they said. They can "power" the units, also, but cannot hookup/turn on the "electric auxiliary" heat, as the electric service still needs upgraded for that. Buddy of mine installs propane and NG generators for homes. He says I probably don't need the 400 amp service upgrade. The geothermal folks say I do. Geothermal folks are footing the bill for the upgrade - it was initially stated it wasn't included, but then they indicated they would cover it to get my business.

    So far, I'm liking the new systems. Little more space taken up in the basement utility closet, but seems to be heating with ease (granted, it's only 48° out right now). Also, they dropped/broke a thermostat and will be bringing a new one Monday to replace it. They are using Lennox iComfort m30 units. Any comments/concerns on those? Quote was for 2 WiFi Water Furnace Thermostats, but I'm not sure if I should press the issue since I know nothing about either (other than iOS reviews of both are not stellar). However, looking online, it looks like the WaterFurance units with Symphony add energy usage stats like compressor, fan motor, aux heat, loop pump, and total energy wattage. Is that something I would want handily available?
     
  13. SShaw

    SShaw Member

    A pressure drop of 8 PSI indicates a flow of about 8 GPM.

    WF does not have a "WiFi" thermostat exactly. They have the "Symphony" platform with the "Aurora Weblink" (AWL) option, which is a WiFi box that connects to the control board on the heat pump. You would need one AWL box per heat pump and the Symphony system would have a dashboard with a separate screen for each unit.

    The monitoring feature on Symphony is excellent, but requires the heat pump(s) be ordered with the performance monitoring packages (energy and/or refrigeration). This is an option on the 5 Series but not on the 3 Series. What is the 5 Series model number you have? That will determine what monitoring options are included.

    The 5 and 3 Series can take either a conventional thermostat or the WF proprietary communicating thermostat. You would need the communicating STATs to integrate with Symphony and the monitoring system.

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