So I have a pair of WaterFurnace Quotes...

Discussion in 'Quotes and Proposals' started by SeekingAdvice, Jun 5, 2014.

  1. SeekingAdvice

    SeekingAdvice Member

    Ok, the basics:
    3300sqft farmhouse south of rochester, ny currently using an 80% efficient forced air system with no air conditioning (which is a big draw for me with goethermal).
    I have attempted the manual J myself as has one of the two companies, both came out around 100kBTU but they are both likely high because 1)I don't know what insulation is in the walls, so we assume none, 2) we checked insulation in the attic at one point (floorboards over the insulation) and the cavity was only 3/4 full, so we assume the entire attic floor cavity is only 3/4 full (but no confirmation).
    However, all is not lost. I can tell you I used 1000 gallons of oil this winter, and based off of degree days I would be somewhere between 50k-60k BTU at a 70F offset (so lets assume 60kBTU).

    Quote 1)
    Waterfurnace 7 series 5 ton
    "6 Ton Horizontal Loop"
    Non-Pressurized flow center
    Touchscreen Thermostat
    Desuperheater
    52 gallon Storage Tank
    52 gallon State Select Electric Hot Water Tank (my current tank is at the end of the life, might as well be replaced now)
    Modify ductwork supply/return plenum. Install new return plenum with welding in turning vanes to increase heat transfer and filtration capacity
    10kWh Aux Heat
    Price: $26k (before tax credit)

    Quote 2)
    Waterfurnace 7 series 4 ton
    Vertical Bore
    Pressurized flow center
    Touchscreen Thermostat
    Desuperheater
    40 gallon Vaughn S-Series Electric Water Heater
    40 gallon Vaughn Aqua Boost Storage Tank
    High Efficiency AprilAire 2410
    Adapt to the current supply and return trunk, line the plenum and drop with acoustical liner, correct all ductwork as needed, balance the duct work to the best of our ability.
    10kWh Aux Heat
    Price: $31k (before tax credit)

    Initially the Quote 2 price was $7k higher using a 5 ton based off of the 100kBTU manual J before I provided that company with my oil consumption data (in which they stated "Oil Consumption Method" put my heat load at 45kBTU, and the "Bin Method" heat load at 58kBTU for a 67F offset).
    Also, quote 1 did not provide me with information regarding how they sized they system, but based on my data (50-60kBTU) it fell in the ballpark.

    So, quote 2 wants to drop down to a 4 ton 7 series versus quote 1 at the 5 ton. Any thoughts as to how that would negatively affect me? How much would I be using aux heat?
    I have seen $2k-$4k thrown around per ton (for adding/subtracting from a system), so that would imply option 2, being $5k more expensive, but a ton smaller, has a net cost difference of $7k-9k (if standardizing to the same size system) right?

    Also, quote 2 wants to use Vaughn water heaters/tanks. Based on what I have found they are pricey. What benefits do the Vaughn tanks have versus whatever homedepot offers or a marathon tank (marathons look to be around the same price as a Vaughn). In terms of water quality, my water is naturally hard (16 grains/gallon) and has iron (1.2ppm). I have a softener that is correcting those things, would high mineral content or softened water affect the stone lining of the Vaughns? Are they worth the cost?

    Would the pressurized vertical bore loop with Vaughn tanks cause the $5k difference in price? are they work the $5k difference in price?

    Quote 2 comes from a company that works with the state to provide a low interest financing option, so I would prefer to go with the company from option 2 (if the state wants to subsidize paying for my geothermal why not). But at $5k (and with a smaller unit) I am assuming it is not the better option.


    Final question. quote 2 also offered a similar quote (lets call it 2a) with the only change being they would use a 5 series 5 ton. for $28k, which gets them closer to the ballpark of quote 1. So, is a 4 ton 7 series work $3k more than a 5 ton 5 series? And how much better is the 7 series? Are the 4 ton 7 series and 5 ton 5 series similar in capacity?

    I know this was a long first post, and I apologize, I have been lurking the board for awhile and I thought I knew enough now to make my own decision. But I need help.

    Please note, I think I am smarter than I am, so I will attempt to answer any question, but it is quite possible I have no clue what I am talking about. So, it might be in your best interest to treat me like a 4 year old when asking questions, if not, you might not get the appropriate answer to your question.
     
  2. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    A well designed horizontal will work as well if not better than a well designed vertical loop field. Vaughn tanks are nice, but not sure if worth the cost.

    7 series is worth the money, hands down. It also puts out a bit more BTUs than the 5 series, that is probably why he proposes a 4 ton 7-series versus a 5 ton 5-series.
     
  3. SeekingAdvice

    SeekingAdvice Member

    Doc thanks for the info.
    Quick question though, you say horizontal loops will work as well if not better than vertical. My impression was that vertical was the best possible efficiency (less seasonal ground temp affect due to depth). How would an equally designed horizontal work better than a vertical? (Understanding ground loops is my weak leak in geothermal, I get what they do, I just don't know the dirty details of what is best (everything is a trade off, it seems with group loops the primary trade off is cost, aka making a compromise in efficiency to reduce overall cost).
     
  4. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    While the ground is much more stable in vertical applications, you have much more pipe in the ground in horizontal applications, so the loop field has a higher thermal inertia. 600-800ft of pipe versus 300ft/ton. In addition, the pipe is further apart then in the vertical borehole which is anywhere between 1-5 inches O.C. So right now entering the A/C, the horizontal loops heat up much slower than the vertical ones, and in the fall cool down much slower, resulting in a higher average EWT. Somewhere between 3-5 degrees. Nothing any software algorithm really accounts for.

    http://welserver.com/WEL0712/ is a horizontal, now around 45F still pretty cold. 7 month ago, at the beginning of December, it was still around 50F

    http://welserver.com/WEL0478/ is vertical, now around 50F already, 7 months ago it was down to 40F already.

    This all means that a vertical loop climbs quicker in A/C and falls quicker in heating mode. If you would have the same amount of pipe in the ground space apart the same, yes then the vertical would be performing better. But that is not the case in the real world.

    If you have 3000 sqf in an older farmhouse where you don't know the insulation, you need at least a 5 ton. And I highly recommend the 7 series.
     
  5. SyracuseGeo

    SyracuseGeo New Member

    @docjenser
    I'm probably going to start an argument here, but I honestly welcome the discussion... I don't see the huge benefit in going with the 7-series over the 5-series. I don't think it justifies the $3-5k add. Marketing literature aside, the improvement in COP between the 5-series and 7-series doesn't seem to have enough payback to justify the price differential (maybe the "7-bration" changes that?).

    Per http://www.waterfurnace.com/literature/5series/SD2500AN.pdf and http://www.waterfurnace.com/literature/7series/SD2700AN.pdf, a 4-ton 5-series has 4.0 COP at full load, 7-series has 3.6 COP at full load. At part load 5-series is 4.6 COP and 7-series is 5.3 COP. But, here's where it gets confusing: the heat output for 5-series and 7-series are completely different at both conditions. It doesn't seem that a truly fair comparison can be made without applying a curve to your load in energy simulation software.

    And by the way, yes, variable speed compressors that match the load are fantastic. Yes, they are quieter and slightly more efficient. And yes, obviously they are the way of the future for residential and light commercial HVAC. No dispute there :).


    @SeekingAdvice
    Good luck with your installation! If the two contractors are who I think they are, I'm sure that the system will turn out well either way.
     
  6. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    The 5 ton 7 series has a compressor which can put out about 4000 more BTUs than the 5 series, thus the heat exchangers are a bit smaller for the compressor capacity than the 5 series. The point is that it reduces the need for supplement heat, even if it runs with "only" a COP of 3.6, which is still much better than 1.0 of electric resistance heat.

    But most of the time the heat exchangers are oversized in relation to the compressor speed, and in combination with a reduced compressor speed and a reduced fan speed, the performance is significantly higher. In addition, the COP is measured at steady state in the lab, but a compressor cycling is not as efficient as one constantly running.

    We measure about a 22% increased performance per delivered BTU in the 7 series versus the 5 series over the season. With a 5 ton unit, that accounts for about a $200 to $280 performance benefit at Western New York Electricity prices. We sell it at a $4k premium over the 7-series, meaning $2.8k after tax credits. That results in a 8-10% ROI, at today's prices, up to everyone themselve to decide wether this is good or bad.

    That all does not account for the increased comfort aspect of it. I don't have one in my house (yet) but the feedback we get from our customers, and the monitoring data are very telling.
     
  7. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    "My impression was that vertical was the best possible efficiency"
    Yes, more efficient means less pipe to harvest needed btu's. That has nothing to do with operating cost.
     
  8. SeekingAdvice

    SeekingAdvice Member

    Doc/AMI thanks for the information. As I have expressed, I understand the idea of the loops, but the tricks to the trade are reserved for the professionals.

    Since I am here, I wanted to comment on my initial post...
    When I stated:
    "Also, quote 1 did not provide me with information regarding how they sized they system, but based on my data (50-60kBTU) it fell in the ballpark."
    A few people may be taken this as I was insulting, or disrespecting quote 1. And I wanted to clear the air. I was not attempting to imply that the contractor for quote 1 did no conduct a calculation, just that he did not provide it to me (nor did I ask), so I was trying to forewarn everyone that I was not 100% sure what methodology was used but I agreed with the end result (which of course means it is right, j/k).

    Lesson for the week: If you don't discuss concerns/desires with contractors, they cannot address those concerns and desires. I have be in discussion with the contractor from quote 1 regarding financing (my primary desire to want to like quote 2), and the quote 1 contractor thinks we might be able to work something out.

    Thanks
     
  9. Josaeph

    Josaeph New Member

    Can you tell me the contract who quotes you quote 1. thanks
     
  10. SeekingAdvice

    SeekingAdvice Member

    I responded to your private conversation.
     
  11. Well back in MAY I was told by the WFI training instructor for the 7 series that they are yet to have a compressor fail in the 7 series. This floored me. Had to have the instructor repeat that 5 times in the 4 day class.
    Wow
     

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