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Need some unbiased input on these 2 proposals

milhouse21386 | Posted in General Questions on

So I’ve gotten 2 proposals from different geothermal contractors and I just wanted some unbiased opinions on the work and equipment. Both proposals came in at around 40k so there’s no huge up front cost benefit from one over the other.

Company A is proposing a 3 ton Hydron YT Series 2 Stage heat pump
Full Load: Cooling 41,200 BTUs at 20.9 EER, Heating 29,100 BTUs at 4.5 COP
Part Load: Cooling 31,500 BTUs at 31.3 EER, Heating 23,300 BTUs at 5.1 COP

Company B has 2 options, a Waterfurnace Series 5 single stage model 030 or double stage model 038
Single Stage: Cooling 27,900 BTUs at 21.1 EER, Heating 20,300 BTUs at 3.7 COP
or
Full Load: Cooling 38,200 BTUs at 19.7 EER, Heating 28,500 BTUs at 4.2 COP
Part Load: Cooling 29,500 BTUs at 28.0 EER, Heating 22,900 BTUs at 4.8 COP

Both systems come with a 10 year parts and 5 year labor warranty (hydron actually has an extra 5 years labor for free if I register the product)

Company A said his calculations came in a little over what a 2 ton unit would handle, so he went with the next size up, 3 tons. The 3 ton would handle any real cold outside temperatures and not resort to back-up electric like the 2 ton would.

Proposal was $37,800, not including needing to hire an electrician to upgrade to 200amps

Company B said the the manual J load calculation showed a 23,165 BTU/HR heat loss so he went with the 2.5 ton unit. He also said that Waterfurnace has been the industry leader for decades and, while the Hydron Module is nice, it lacks the more sophisticated electronics found in Waterfurnace products. Hydron uses very basic mechanical controls without adequate protection from things like freezing. His initial proposal was for the single stage, but he said for an extra $700 I could get the double stage.

Proposal (Option 1) $38,800

Proposal (Option 2) $39,500

There’s also an option to upgrade my electrical to 200amps for an extra $1,800.

Company B will also remove the baseboard radiators from the house.

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Replies

  1. user-6944519 | | #1

    Your heating contractors performed their manual J calculations based on how your home currently is. How well insulated is your home? If you first spend $2-3k on insulation, you could instead install a smaller 2-ton unit. Then you will likely spend less on your geothermal system and you'll get the benefits of adding insulation: lower energy bills, increased comfort, etc.

    I'd go back and ask your contractor(s) to perform their manual J calculations with anticipated levels of insulation.

  2. Expert Member
    Dana Dorsett | | #2

    It would be worth having company A bid it at 2-tons + heat strips. If the Manual-J came in just "...a little over what a 2 ton unit would handle..." it's possible (or even likely) that the heat strips wouldn't even be needed some years.

    Oversizing to cover a minor shortfall never makes economic sense. Even when the heat strips are engaged the lion's share of the heat would be provided by the heat pump. If the 2 tonner only has you fully covered up to the 95th percentile temperature bin that's still going to be the right choice.

    The YT024 puts out 19,000 BTY/hr at full load at a COP of 4.3, 15,200 BTU/hr at part load at a COP of 4.8. You AVERAGE winter load is going to be a lot closer to the 15,200 BTU/hr number than the 23,300BTU/hr low stage of the YT036 (which covers the 99% or 99.6% load as calculated by the other contractor.)

    Most Manual-Js performed by contractors overshoot reality by at least 10-15% which means the "real" load is more likely to be in the 19.7- 20.8K range. But even if the real load is 23,175 BTU/hr, that's only burning and "extra" 4165 BTU/hr (= 1200 watts) of heat strip to cover that load. Even if that adds up to 5% of the hours in a year with heat strip engaged at an average of 600 watts, that's still less than 300 kwh per year.

    Same story for contractor B. The single stage 20,300 BTU/hr option is fine size-wise, but a COP of only 3.7 is pathetic compared to the other models. (There are air source heat pumps that can hit that for a seasonal in a zone IV climate.) The COP rating doesn't even include the ground loop's pumping power, so as a system it's going to be lower.

    The 2-stager is fine from a COP perspective, but oversized for the load. Every time the compressor had to spin up there is some amount of energy wasted. Oversizing that guarantees that the system is almost always cycling on/off rather than stepping from low to high speed can burn more kwh in lower as-used COP than a modest amount of heat strip use. Ideally with a 2-stager high stage output would cover at least the 95th percentile temperature bin load, and the low speed be low enough to guarantee very long cycles at the average wintertime load. The equipment as specified looks like the low-stage would cover the 95% load. A 2-ton Waterfurnace still delivers 19,500 BTU/hr at the high stage (which might be your real heat load) with 32F water, adn a more moderate 16.5K at low stage with 41F water.

    Of course the ground loop design and pump specifications can make or break any of these systems on capacity & efficiency, all part of the risk when going with ground source heat pumps.

    For the kind of money we're talking here it's worth paying an independent engineer or RESNET rater to run a properly aggressive Manual-J on the house, and maybe even recommend cost-effective load reduction measures. At $13-$15K/ton there are lots of things that are cheaper than an extra half-ton or ton of heat pump + ground loop. Knocking off a ton isn't going to save you $13-$15K, but it should save at least half that. All else being equal a ton of reduced load is a better investment in comfort than a ton of GSHP, even if the power to run that additional ton was free.

  3. GBA Editor
    Martin Holladay | | #3

    Milhouse,
    As the previous commenters have pointed out, there are at least two issues here:

    1. The quality of your home's thermal envelope.

    2. The accuracy of the Manual J heating load calculation.

    You haven't told us your geographical location or climate zone. Nor have you told us whether this is a new house or an existing house. So it's hard to give advice.

    In general, it's rarely necessary to spend $40,000 for a single-family home's heating and cooling system. Here at GBA, when someone tells use that they are about to spend $40,000 for HVAC equipment, our usual advice is, "Wait a minute. Are you sure you need that much equipment?"

    I'm just guessing, but it seems likely to me that your home could benefit from energy upgrades (air sealing work and insulation improvements). And in most cases, you want your Manual J calculations to be performed by someone other than your HVAC contractor.

    Once you tell us more about your house, and where it is located, we can give better advice.

  4. milhouse21386 | | #4

    Hi everyone, thanks so much for the advice so far! I live in Connecticut and right now I have oil heat through baseboard radiators, my house has a full basement (unfinished) and one floor, 963 square feet, 3 bedrooms. I've already scheduled to have an energy audit performed, Connecticut has an energize program where they try to help people make their houses more energy efficient, someone will come to the house and do a blower door test and seal and insulate the house where they can and give me recommendations about what else I can do. If they don't perform j calculations I'll make sure to hire someone that does to come out and do one. The energy audit is scheduled for July 19th right now.

    I was told by both contractors that the reason the price is so high is because there's no existing ductwork, so the system has to be retrofitted to the existing house (relatively simple as it's one floor and the basement is unfinished for installing the ductwork), the oil boiler and tank need to be removed, and I also need electric water heaters to be installed to provide usable hot water for the house. Both contractors also proposed using 2 water heaters, one would be unwired, more as a storage tank to store room temperature water so the wired electric water heater won't have to work so hard to heat up the water.

    Completely uninformed question here, but how much of a price difference is there between 2 and 3 ton units? My biggest worry about all of this is reading stories of people who've gotten geothermal, their unit wasn't sized correctly, they have a cold winter and their electric bill ends up being ~$800 a month because the electric backup comes on. I'm going to be super upset if I spend all this money on geothermal and my monthly bill winds up being more expensive than if I stayed with oil. What would be the price savings of going with a 2 ton unit with heat strips or just a 3 ton unit?

    I'm really sorry if I'm asking a lot here, I just don't know anything about any of this heating stuff and it's a huge investment. My last house I converted from oil to gas and it was super easy. The house was already hooked up to a gas line so it was ~$10,000 to put in the new furnace, financing it was $40/ month and I immediately saw savings in my heating bill. So all of that was a no brainer as the initial install wasn't insanely expensive and I immediately started saving money every month. But the geothermal is a completely different beast. I'm looking at either 25k out of pocket and a $130/month loan to finance the rest, or it's about $350/mo to finance the whole thing, and I'm just so worried about seeing my electric bill go through the roof if we get some crazy cold winter like we got last year (it was in single digits for while).

    I really appreciate all of the help and I apologize if I don't completely understand the answers and ask the same thing again.

  5. GBA Editor
    Martin Holladay | | #5

    Milhouse,
    I'm glad you provided more information. The two most important facts are:

    1. Your house is quite small.

    2. You are planning to perform energy retrofit work.

    You put the cart before the horse when you sought bids for a ground-source heat pump (sometimes called a geothermal system) before the energy retrofit work is performed.

    Step one is to finish the retrofit work, which will almost certainly include air sealing work, and which may include basement insulation work (unless your basement walls are already insulated).

    Step two is to get a competent Manual J calculation from a disinterested professional, using information from the post-retrofit condition of your house (including the final blower door number). Here is a link to an article to guide you: "Who Can Perform My Load Calculations?"

    Note that your heating load will be considerably smaller after your retrofit work is complete than it is now.

    Once you have accurate load calculations, you can design a heating system. With such a small house (only 963 square feet), you can almost certainly heat and cool your house with one or two minisplits, at an installed cost of $12,000 or less.

    For more information on why green builders are choosing minisplits over ground-source heat pumps, see these two articles:

    "Just Two Minisplits Heat and Cool the Whole House"

    "Are Affordable Ground-Source Heat Pumps On the Horizon?"

  6. Jonathan Blaney | | #6

    Can you tell us your long term goals? Is this your forever home? It will take a long time to recover the cost of these systems. Have you looked into water-to-water systems? I went through a similar process and decided to spend $600 on two window a/c unit and to tune up my ductwork. $40,000 will buy a lot of oil.

  7. milhouse21386 | | #7

    Awesome, thank you very much for all this info. I'm definitely going to ask if the energy audit includes the manual j test and if not, find a contractor who can perform the test. I'm also definitely going to look more into the mini splits, I'm assuming with hat I'd probably still keep the oil furnace as a backup to be safe for the first year at least, plus it provides hot water for the house. My only worry there is that we just bought the house and the current oil furnace looks like it's about 30 years old. I was also trying to consider that in looking at geothermal, instead of spending money on a new oil furnace that money would have gone towards the geothermal instead.

    I'm also going to tell the contractors that I'm going to be getting an energy audit on the house and that, while geothermal isn't completely off the table yet, I'm going to wait until after the audit is done to see if there are any more cost-efficient solutions for the house.

    Long term goals are this is our forever home. We're going to be looking into getting solar panels installed at some point, hopefully next year, and try to make the house as energy efficient and eco friendly as possible.

    I will definitely update after the energy audit is performed and do a lot more homework on these minisplit devices.

  8. milhouse21386 | | #8

    Oh sorry I forgot to address one thing, ideally I want to use as little oil as possible going forward, if not remove the entire system when possible.

  9. GBA Editor
    Martin Holladay | | #9

    Milhouse,
    If you are heating and cooling a 963-square-foot house in Connecticut with a minisplit, you definitely don't need an oil furnace for a backup. Your heating load will be low, and the minisplit can definitely handle it.

    Get that oil-fired beast removed from your basement, and buy a well-insulated electric-resistance water heater like the Marathon or a heat-pump water heater.

  10. Expert Member
    Dana Dorsett | | #10

    A load of 23K at positive single-digit outdoor temps for a ~1000' house is excessive, implying a low performance building envelope and lots of low-hanging fruit.

    The Manual-J is not a test, it is a calculation of the load based on the actual house construction. Do NOT have it done by an HVAC contractor- use an independent third party who makes a living on the accuracy of their numbers rather than making it on installing & servicing HVAC equipment.

    For the kind of money you're talking you could spend $5K on tightening up the place, $8-10K on ductless or ducted mini splits (or a combination thereof) , and a heat pump water heater and have $25K left over to spend on rooftop PV (6kw+, more after factoring in tax credits and local incentives), which would be enough to offset ALL of your heating energy use!

    Right-sized cold climate mini-splits will have an all-in COP north of 3.0, bumping on 3.5 in your climate. If the ground source heat pump contractor doesn't do a great job. on both the ground loop and pumping specs a 4.5-ish COP Waterfurnace won't be more efficient than that as a system.

    A cold climate ductless Mitsibushi 1-ton FH12NA delivers over 13,000 BTU/hr @ +5F and in competitive bidding comes in at about $4K, sometimes more, often less.

    http://meus1.mylinkdrive.com/files/MSZ-FH12NA~MUZ-FH12NA_Submittal.pdf

    A 1.5 ton Fujitsu 18RLFCD mini-ducted unit puts out over 20,000 BTU/hr @ +17F (I'd have to consult the engineering data to determine it's output at colder temps, but it's fully specifed down to -4F) and should come in under $7K, including ducts.

    http://portal.fujitsugeneral.com/files/catalog/files/18RLFCD1.pdf

    Depending on floor plan you may want do all ductless, all ducted, or one of each type, but this is totally do-able, even EASY (compartively) for a house that size with a full basement for routing ducts (if needed.)

    Hartford's 99% outside design temp is +6F, Waterbury is +2F, coastal areas are in double-digits:

    https://articles.extension.org/sites/default/files/7.%20Outdoor_Design_Conditions_508.pdf

  11. Jon R | | #11

    Since you already have hydronic baseboard radiators, I'd look into using a Chiltrix air to water heat pump. Possibly with the addition of a few fan coils (to allow AC and to account for the lower water temp from the Chiltrix). Should be quite cost effective: http://www.chiltrix.com/documents/price-list.html

    +1 on getting an energy audit (including a blower door test).

  12. Ryan Magladry Ottawa, Ontario | | #12

    just to give some perspective. the heat load for my new build, 2000 sq ft single level, well insulated, air tight with good windows, and full conditioned basement came in at 22,500btu/hr, in eastern ontario.

    I'm going with 4 mini splits heat pumps (3 ductless mitsus - 9K, 6K, 6K, and a ducted fujitsu 9K). The bid for the 4 units plus duct work is 16,500 cad + 13% tax. Another 4,000 for the ERV.

  13. Expert Member
    Dana Dorsett | | #13

    Apparently you have a heating history on the place with the oil burner(?). If you have some mid to late winter fill-ups and quantities (with exact dates) and a ZIP code it's possible to use the boiler to measure the heat load of the house in it's current "pre updates" condition. See:

    https://www.greenbuildingadvisor.com/blogs/dept/guest-blogs/out-old-new

    If you're on a regular fill-up service that stamps a "K-factor" on the billing slips, some wintertime K-factors and your 99% outside design temp would be enough information to be able to put some realistic stakes in the ground for the likely whole-house heat load.

    Fuel-use based load calculations won't give you the necessary room-by-room load numbers needed for figuring out the zoning, but it's a good thing to have as sanity check on other load calculation methods.

    The odds that you would be able to run the heating system as-is with a reversible chiller like the Chiltrix are pretty low, unless you have three times the amount of baseboard that would be needed to heat the place with the oil boiler. There is a bit of design risk and probably far less local support for that type of solution than for modulating air source heat pumps (mini-split).

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