Tennessee Getting quotes, but no Manual J

Discussion in 'Quotes and Proposals' started by mrh218, Sep 28, 2018.

  1. mrh218

    mrh218 New Member

    Hi all, new here! I am in the process of getting quotes for a retrofit. I have seen 3 installers, with a 4th coming tomorrow and expect to get several quotes in early next week. However, no one has offered to do a Manual J load calc.

    Is this calculation something I should ask them to do?

    I am replacing a 4 ton heat pump and I tell them that it has kept us comfortable. (Though, now that I am thinking of it, it does kick on the electric heat during those colder days/nights.) They ask about square footage (2500 sq ft) and agree that 4 ton is accurate.

    We have lived here for about a year. Though I don't know the history of the house, I think the builder must have installed a 3 ton unit (about 20 years ago) because the return vent has to be enlarged. The existing heat pump system is 9 years old, so I assume they upgraded because the 3 ton wasn't cutting it in the summer.

    Thanks!
     
  2. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Your consumption (or sizing) experience is probably more precise than doing a manual J, where you have to guess what is in the wall and how your envelope is performing.

    An interesting approach would be to put a larger unit in (5 tons) to cover more or your colder nights, preferably a variable speed units, so it runs at much lower and more efficient speeds the rest of the time.

    If I would have the information you given here, I would put in a 5 ton 7 series and let it find its matching speed to whatever the outside temperature is, ...and not bother with a manual J, and you would be extremely happy camper for many years to come.
     
  3. mrh218

    mrh218 New Member

    Thanks for the input docjenser. Wow - I just realized that the 7 series has a variable speed compressor. Are there any others with that feature?

    I did notice that none of the installers recommended Water Furnace. We have been discussing split units because that works better for my situation. Maybe that's why the 7 series hasn't come up.
     
  4. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Why would split units work better for you?
     
  5. mrh218

    mrh218 New Member

    The loop location would be just on the other side of the wall where my water heater is. The pump and compressor would be next to the water heater and the refrigerant line would go about 40 feet to where the air handler is.

    It's definitely not required as we could use a package system, but seems to make more sense than running the loop past the water heater and then back. I'm more interested in efficiency (and price) than how it looks, so please let me know if I am overlooking something here.
     
  6. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    40ft of more pumping (one way) would not hold me back if I could get a packaged 7 series instead of the 5 series.
    If you use a desuperheater put the buffer tank next to the unit, and keep your water heater where it is. DSH output is much more with the 7 series, due to the much longer run time.
     
  7. mrh218

    mrh218 New Member

    Thanks doc. The more I read, the more the 7 series seems to be the best unit.
    I am waiting for a Waterfurnace dealer to call me back. The other WF dealer I talked to didn't even mention WF when I asked him what brands he installs, but I didn't bring it up either.

    The quotes I expect to get today are all from installers whose names kept coming up when researching and have a lot of geo experience. I also had a lengthy conversation with the drilling company that it seems everyone here uses to drill the wells and he gave me the low-down on who to use! These companies have said they install Bosch, Climatemaster, Geocomfort, and the typical conventional brand names for residential air heat pumps like Carrier and Trane.

    I guess they are all looking at 2 stage compressors to keep install cost down. We also cool more than heat and a package unit (I believe) would have to go on a stand to allow for my 2 return ducts from the left and right of the unit.

    Should I also consider the Trane TVGX as an alternative?
     
  8. flywilson02

    flywilson02 New Member

    If you're in the middle TN area call Precision Air if you haven't already. They recently installed our WF 7-series and provided a fantastic installation experience.
     
  9. mrh218

    mrh218 New Member

    Great flywilson02! Their geo guy is who I'm waiting to hear back from. I just checked your posts and your system is similar to mine: 4 ton, two 300ft wells, but only minor duct work and no zoning. Did they give a line item with the cost of the 7 series or install costs? I get the feeling that some of the bigger HVAC companies around add quite a premium to the drilling operation.
     
  10. flywilson02

    flywilson02 New Member

    They did not give me a line item cost for the unit, and they were not the cheapest quote for our job. Everything I read on this site about the WF 7 series units, and the importance of a quality installer made choosing them a no brainer to me. I would be curious to see their costs for the install. As you mentioned I'm sure the middle man cost for the drilling is steep. In total the drilling crew spent ~2 days drilling and grouting our wells then trenching to the house. The HVAC crew had 2 or 3 guys at our house for the better part of 5 days including one of the tech's staying until after 7pm to get our system running one night later in the installation week.

    We've only had our unit in for about 6 weeks, but have been extremely impressed with the comfort it provides. We should receive our first full electric bill in the next few days. According to the thermostat its been averaging about 12-13 KW/hr per day to operate the unit with average highs in the low 90's for the end of August and most of September. I don't know what our previous units were using but I'm sure it was more than that, and we've lowered the thermostat settings by several degrees.

    Let me know if there are any other questions I can answer for you.
     
  11. mrh218

    mrh218 New Member

    Well, I am narrowing down the choices:
    • I finally heard back from Precision, but I just cannot afford their prices for the WF 7 series. The other WF installer is not nearly as experienced and I don't feel comfortable hiring them for geo.
    • Following the recommendation of 5 installers, I have decided that a split system works best for my needs.
    These are the options I have narrowed it down to. Note that these quotes are for the HVAC side only. The drilling is hired separately:
    #1 - 4 ton Carrier 2-stage Variable speed split - $10,650
    #2 - GeoComfort BT048 with Ruud air handler - $9,670
    #3 - Air source heat pump. If geo doesn't make sense.

    I'm leaning toward #2 as he's been installing geo for ~25 years and has good recommendations. Both are recommended by the driller.
    The driller will handle all of the loop and pump install and has a lot of experience with both installers #1 and #2. He has been installing geo loops for 40 years and almost everyone in town uses him at times. His quote adds $7,860 to either option.

    I look forward to any input. If there is a chance I won't be happy with either of these options and would prefer an air source heat pump, I would just go with that. In other words, if I need to spend significantly more because the Carrier or GeoComfort equipment is inferior, then I would likely opt out of geo.

    Thanks!
     
  12. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Both Carrier and Geo Comfort (Hydron clone) are dual stage systems and should serve you well, if you are on a budget and do not want to afford the 7 series. Not sure who makes Carrier units, it used to be Climatemaster, but I am not sure who make it now. I'll have to check.
    As always, experience of the installer is key.
     
  13. mrh218

    mrh218 New Member

    Thanks docjenser. Good to know! I am surprised at how many experienced installers are around here.
     

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