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  1. #1
    Join Date
    Jan 2002
    tip of the mitt

    geo best practices

    I'm starting to branch out into geothermal. Been to climatemasters training and waterfurnace training. Have installed a few geos over the years. I have settled on waterfurnace as a brand.

    Earlier today I looked over a job a geo contractor installed about ten years ago. He retired earlier this year. He installed mostly pump and dumps. Pump and dumps are very common in my area.

    There are a few things I noticed about his installs and am curious about his methods.

    For supply and discharge piping he used 3/4" pex piping. He installs without return air duct. The house is cut in like any new home but there is no return air duct, this can be basement or crawlspace. His supply air ducting isn't insulated. He had ten 6" runs off a 16 by 8 trunk. On the hot water generator he used to 40 gallon electric water heaters, only one of them was wired into 240 volts. Any thoughts?
    I have my own little world. But it's OK...they know me here.

  2. #2
    Join Date
    Feb 2009
    Portland OR
    Well as for the ductwork... Goes are pretty much the same as any other system, size based on CFMs

    As for the water heaters that part is done right. The first tank is your preheat storage tank, the second tank is your actual water heater. The first tank with no electric is hooked to the desuperheater so it could be filled with 60 degree water up to 115 degree water depending on geo size, domestic water load and time of year.
    I don't mean to be rude but if you don't understand this setup and operation of desuperheater and storage tanks you need to go back to the classes, this is geo 101 stuff and hugely important for installing properly and maximizing efficiency/savings for the homeowner.
    Check out my YouTube channel - We have customer testimonials, product reviews and more!
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  3. #3
    Join Date
    Jan 2002
    tip of the mitt
    Thanks for the reply. Waterfurnace is a new product for me and it's been a few years since I've installed geo. We used mostly econair back then, not many jobs though.

    Looking through waterfurnaces design manual that was given to me at the classes I took, it says to use a 50 gallon water heater for hot water generator applications. If it is a high demand application, it is recommended to use a 80 gallon or two 50 gallon water heaters. When I saw this other job with two tanks in a low demand system, I wondered if something had changed in design recommendations or was considered best practice. The same with the uninsulated duct. The same with the 3/4" pex supply piping. The job is different than the way I install. When I say different I don't mean wrong.
    I have my own little world. But it's OK...they know me here.

  4. #4
    Join Date
    Mar 2012
    West Berlin, NJ
    Buffer tank water heater set up is more the normal practice than good practice.
    Pump and dump can run on a 3/4 pex line if it is a smaller system. It all depends on the flow the system needs.
    Dan Callahan
    Get "well educated" with us!

  5. #5
    Join Date
    Jun 2013
    Quote Originally Posted by tinman View Post
    ...3/4" pex piping.
    [[ although on open loop pex or plastic - right out of any water-source GSH, water cooled anything, for several feet is not recommended best, because HW from a cooling-mode, if a redundant safety fails, the leaving water HAS been known to soften fittings and drain on the floors]]

    He installs without return air duct.
    [[ probably get something simply to the floors above to rid basement negative pressures, increase envelope efficiency as you do in any Hi eff A/c, furnace, ---]]

    or crawlspace
    [[, sealed,? insulated? some "may" get by, but never seen recommended for most applications (96%+)]]

    . His supply air ducting isn't insulated.
    [[ DEP: 8 feet out may be enough; sealed is more important if losses and humidity are not an issue. Some homes benefit greatly from duct radiant heating to the oint of warm-air blanketing the ceiling under flooring yields substantial floor radiant heating (been done by design).]]

    He had ten 6" runs off a 16 by 8 trunk.
    [[ if under 2 tons on that trunk, not much worry; and see if you need to damper the last runs to get air to the first couple--- duct 101 - a later]]

    [[What DeSuperheater-Tank info above says, and well described for HW GeoThermal 101.]]
    If your getting back into all:
    please take a moment to review and call other OEM's at sites below, many references/ efficiencies.
    blended efficiencies of 3-staging ((i.e.- Dual compressors staging sm + lg + then both)) or VFD variable compressors are in the EER's of 40+ because most running hours are in low to med speeds for /~ over 75% of the annual utilization. A highest COP may have a higher annual cost of operation, as you may have seen already.

    you mentioned DSH
    now some have had for a while, priority HW instantly on demand, as well as simultaneously in cooling mode; loop pumps are "off" heating HW 100%, then and programmable.
    ... however, much work still needs to be done.
    CLOSED LOOP newer ratings are listed, but in numerical EER's Closed- is posted below OPEN LOOP EER's:

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