Replacement unit for Open Water to Air

Discussion in 'General Discussions' started by BenD, Jun 25, 2013.

  1. BenD

    BenD New Member

    hi,

    I am new to geothermal discussions in general because I bought a house about a year ago that had two 4 ton units used to cool and heat the entire house.

    Specs of system: 2 4 ton Water to Air.
    Location: Northern Florida
    Open cycle.
    Source: Well
    Make: Marvair (1981 for both units, but first unit is already replaced with conventional unit.)

    Something we did not practice due diligence when purchasing the house on was the fact that the system is 31 years old and the units are very inefficient. We had to replace the upstairs unit already when it stopped working and the repair cost was estimated at around 3,000. Because of that and the high cost of these Marv Air units to operate (Marv Air no longer even makes water to air units for residential anymore) and so we got it replaced and immediently noticed a cost improvement with a traditional unit. Since that has happened and Summer is here again, I am looking to getting the second unit (possibly) replaced with a newer and more energy efficient unit. I say possibly because if its not economical to go for the same set-up with geothermal I might just replace the second unit as well with a traditional air cooled heat pump. The unit I am replacing has to heat as well as cool. (this is not always clear with Florida based units)

    My first question is on the federal income tax deduction. I read everything I could about it and have had difficulties finding out information such as whether a replacement system installed is eligible for this or is it just for brand new installed systems?

    Second question is about the open water cycle. Is a closed water cycle worth looking into?

    Third question is about who to hire to do the job. FPL (Florida Power and Light) offers incentives that are quite nice in all honesty to go with one of their approved contractors but I am skeptical on how much those contractors might know about geothermal units (or water cooled units.) What do you all think?

    Thanks for taking the time.
    -Ben
     
  2. Your units are really old! That does show the durability of geo units in general. Yes the 30% rebate applies to replacement units if they meet the Federal guidelines, and most do. Open loops work ok, but you are wearing out a well pump. You must have decent water, since the old ones lasted so long, so I guess water quality damaging the heat exchangers is not an issue. Most geo installers lean towards closed loops long term, but the upfront cost is a little high. If you do it while replacing your units you can get the 30% rebate on that as well.

    I am new to geothermal discussions in general because I bought a house about a year ago that had two 4 ton units used to cool and heat the entire house.

    Specs of system: 2 4 ton Water to Air.
    Location: Northern Florida
    Open cycle.
    Source: Well
    Make: Marvair (1981 for both units, but first unit is already replaced with conventional unit.)

    Something we did not practice due diligence when purchasing the house on was the fact that the system is 31 years old and the units are very inefficient. We had to replace the upstairs unit already when it stopped working and the repair cost was estimated at around 3,000. Because of that and the high cost of these Marv Air units to operate (Marv Air no longer even makes water to air units for residential anymore) and so we got it replaced and immediently noticed a cost improvement with a traditional unit. Since that has happened and Summer is here again, I am looking to getting the second unit (possibly) replaced with a newer and more energy efficient unit. I say possibly because if its not economical to go for the same set-up with geothermal I might just replace the second unit as well with a traditional air cooled heat pump. The unit I am replacing has to heat as well as cool. (this is not always clear with Florida based units)

    My first question is on the federal income tax deduction. I read everything I could about it and have had difficulties finding out information such as whether a replacement system installed is eligible for this or is it just for brand new installed systems?

    Second question is about the open water cycle. Is a closed water cycle worth looking into?

    Third question is about who to hire to do the job. FPL (Florida Power and Light) offers incentives that are quite nice in all honesty to go with one of their approved contractors but I am skeptical on how much those contractors might know about geothermal units (or water cooled units.) What do you all think?

    Thanks for taking the time.
    -Ben[/QUOTE]
     
  3. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Ben,

    Where in North Florida are you? We are a WaterFurnace dealer located in Jacksonville. We also install conventional air source split heat pumps.

    We can work through the economics of sticking with geo or changing to air source systems. Much depends on the specifics of your situation; we specialize in deep home energy audits designed to determine the best HVAC solution for a particular home as well as to highlight other energy cost saving opportunities (water heating, kitchen, laundry, lighting, pool pumping, etc)
     
  4. BenD

    BenD New Member

    Thanks for the answers. As for the reliability of Geo, yea I am counting on being able to install a good system today and not have to worry about it for 15 years and being able to tell people that it has a much better system if we do end up moving. Although normal HVAC's are like that as well, I am thinking that if you get the more efficient system now it will pay off since we do plan on living here for a long time. I am actually looking at it and I am pretty sure it would actually cost more to install the conventional system because the install at our house would require a lot of electrical wiring and a partial rebuild and/or addition to our circuit breaker. The only issue I still have is that we have had a couple leaks with the system (I am thinking this is because of the age of the components and/or operator error as I was manipulating a sprinkler head one time and did not check it out before leaving the room.) It would require some work to re-do that section of the house just to be sure since the floors are wood in that room.

    Quick question while I am thinking about it, how do I compare Geo systems with conventional systems? I saw that the conventional systems have a system called SEER while most Geo systems are rated in EER. Are these the same scale? Thanks again for the help!

    Curt, I will try contacting you guys, but out of curiousity are you on FP&L's approved contractor list?

    We are located in Wellborn, FL which is about 10 minutes west of Lake City. Its about an hour and a half drive to get to Jacksonville from here.
     
  5. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    We are not on FP&L's "approved contractor list", but only because the question has not come up to date. We are on JEA's (Jacksonville) list and in fact work very closely with JEA's conservation crew to train contractors, homeowners and business owners on whole home / building energy performance. We provide content for their print and TV media campaigns, work with them during home shows, etc.

    Getting onto a utility's approved list is generally a matter of merely filling out forms and providing proof of licensure and insurance...not much more than a "fog a mirror" test.

    SEER vs EER - good question. SEER is a "blended" performance rating that attempts to assess the performance of conventional air source systems during average conditions. Unfortunately it is overly weighted toward indoor and outdoor conditions that are fairly rare in actual operation. EER is a more rigid rating, Btus transferred per Watt consumed during 95*F weather. SEER tends to exceed EER by 20-30%. Refer to articles at The Energy Vanguard by Dr Allison Bailes for excellent explanations of HVAC performance, tonnage, etc. Look at AHRI ratings where SEER and EER ratings are both provided. Air source heat pump and AC manufacturers LOVE SEER because it puffs up ratings. Getting EER ratings from them is like pulling teeth, but the data is there. Know also that high SEER rated (16+) air source systems are typically two stage, and the advertised SEER rating is delivered only during low stage operation, not while the system is running in high gear during a hot afternoon

    The 95*F outdoor air temp aspect of EER doesn't apply to water source (Geo) systems since their performance is unaffected by outdoor air conditions. But there is another wrinkle affecting Floridians considering geo systems - There are several EER ratings published for geo systems, but the headline ratings are based on 59*F groundwater. That's useless to us here since the nearest source of 59*F groundwater is about 600 miles away, which is a bit too far to economically pump, not to mention the right of way issues likely to arise with a 600 mile long loop field.

    Another factor ignored by geo ratings is water pumping power beyond that required to push the water through the system's water to refrigerant heat exchanger. Those heat exchangers are designed for low pressure loss to aid in achieving high EER ratings, but a typical open loop system can have pumping power 5-25x the rating's allowance, rendering the advertised EER meaningless.

    Lake City is a bit beyond our typical combat radius, but we'd take the right project at that distance if we could add sufficient value to justify travel time and expenses, ideally during a slow time of year, late fall or early spring.
     
  6. Jerry_NJ

    Jerry_NJ Member

    My 20 year old WaterFrunace was trouble free for 15 years, since I has cost some for repairs. My experience says 15 years? Yes, can do.
     

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