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Help with new HVAC and oil boiler

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wlee
wlee Member Posts: 15
edited April 20 in Oil Heating
We are getting quotes to replace a 24 year old central air and 40+ year old oil boiler for our home in the Hudson Valley area of New York state. The home is a raised ranch, approx 2000 sq ft, with upper and lower floors. The central air unit covers the upper floor only, with ceiling registers. There is one register in each of the three upstairs bedrooms, one in the kitchen, one in the dining room, and two in the livingroom For heat, we have hydronic baseboards throughout the house, split between two zones, one for the upper floor and one for the lower. DHW is provided by an indirect water heater, so the current boiler is split into three branches, one for each heat zone and one for the indirect tank. NG is not available in our area, and I am not interested in propane.

I've asked the contractors to quote me a price to replace the central air unit with an air source cold-climate heat pump, which would drive an air handler in the attic for the upper floor (using the existing ducts) and two minisplit units for the lower floor. The two minisplits would cover most of the lower floor, omitting the lower floor bathroom and a guestroom. My expectation is the heat pump will provide cooling for the entire house in the summer and most of our heating needs in the winter.

I would like to keep the boiler for DHW and backup/emergency heat. I am considering replacing the boiler with something new, as I am reluctant to electrify everything, and am doubly reluctant to rely on such an old boiler. My understanding is that even cold-climate heat pumps work harder on very cold days to keep up, and it might be cheaper to run the oil boiler for heat on those days. In addition, our current boiler is wired into a generator panel (only 120v circuits), so when we lose power in the winter, I can still have heat and DHW by running the boiler off the generator. I would be reluctant to lose that capability, as the generator could not run the heat pump.

My goal is to replace these two systems with units that will allow me to use as little oil as possible. One contractor quoted me for an EK System 2000 boiler, which seemed really excessive for the way I intend to use it. While researching this purchase, I came across boiler terms like high mass vs low mass, cold start, heat purging aquastats, etc. As a non-pro I'm finding it hard to reconcile all these different options. My contractors are trying to help, but I am constantly peppering them with different requirements, and at this point they believe I don't know what I want, which unfortunately is probably true.

My novice reading of the literature would imply a low mass, cold-start boiler that would only fire when we needed it would be ideal, except that the indirect tank would be calling for heat all year long, which I assume would defeat the purpose of cold-starting. The System 2000 boiler literature discusses purging unused heat into the last zone that called for it, and it seems there are aquastats available for standard boilers that would accomplish the same thing - but again, how useful would they be with the indirect DHW tank? Some of the pros suggesting replacing the indirect tank with a heat pump hot water heater, but if I did that I would not be able to use the generator for hot water if the power went out.

Of course, we don't lose power all that often and I start thinking I'm over-analyzing and I just shouldn't worry about using the generator. But, I have it, it's already wired into the house and connected to the existing boiler.

Apologies in advance for being all over the place. In the end I'm looking for some guidance on what might be the best combination of equipment that would allow me to get off the oil as much as possible for heat, while still keeping it available for DHW, excessively cold days, and power failures. While not spending a fortune :-) I have a budget in mind for this project, but I think the website rules ask us not to post pricing.

Thanks in advance.

Comments

  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
    edited April 20
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    It’s quite possible the existing boiler is in good enough shape to stay! 

    Otherwise, you’re thinking along the right lines. Don’t go overboard when you’re intending to use it sparingly. There are not substantial efficiency gains between oil boilers anyway. Find a contractor you trust and go with what they are most familiar with. 

    With this set up, you can size to cooling load, which will be a bit undersized for heating (if they actually size correctly for cooling), but that’s okay. 

    As for the indirect - don’t let DHW wag the dog here. DHW is usually a smaller load than heating or cooling, so keep the indirect if you want or install a standalone unit. Both will be satisfactory unless you have a gigantic hot tub. 
  • Jamie Hall
    Jamie Hall Member Posts: 23,455
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    First off, "Hudson Valley" is, unfortunately, a bit vague so far as weather and demands on heating is concerned. Where? Tarrytown? Albany? Hope? There's a 20 degree spread in there as to "cold".

    Now having said that -- your requirements are actually pretty simple: you want to stay warm in winter and you don't want to spend a fortune on either equipment or energy.

    And having said that, the real question is not whether, but when to plan the changeover from the heat pump to the oil boiler, and what oil boiler to get to replace the one you have. My recollection is that wherever you are in the valley, your electric rates are pretty high. Heat pumps -- cold climate or not -- rapidly lose efficiency as it gets cold, although the relevant information can be hard to find. You should be able extract the information on COP (coefficient of performance) vs. temperature from a dealer, though "extract" is the operant verb there. That will allow you to calculate at about what temperature it becomes cheaper to run the oil burner -- and my guess is it's going to be around 20 F or so.

    Hot water. If you are going to still use the indirect, you will want to keep the warm start on the boiler. It is less efficient, but not outragsously so. As you note, the problem with an electric water heater or heat pump water heater is that they may overload your generator, depending on what size it is. You might consider an oil fired hot water heater, but that would require an additional flue -- which you may not have.

    On asking questions and so on of contractors. The very most important thing in all of this is to find a contractor who really truly knows what he or she is doing and who inspires confidence. And then listen carefully to his or her suggestions and considerations -- and let them get on with it. The best equipment and the best planning in the world can be ruined in twenty minutes by an incompetent contractor.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    bburdEdTheHeaterMan
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
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    @Jamie Hall Mitsubishi, carrier, and LG at least make their COP data available. Mitsubishi has it on their mylinkdrive website, it’s easy to find. I don’t know about the others. 
  • Jamie Hall
    Jamie Hall Member Posts: 23,455
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    A decided and welcome step in the right direction!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Hot_water_fan
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
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    It’s usually presented at outdoor temps in 5F increments, a few different indoor temps and different outputs (100%, 75%, 50%, etc). Pretty usually. 

    Something for @wlee to consider is going with a NON cold climate heat pump and use the oil when it’s very good. Sometimes that works out to be more efficient. 
  • wlee
    wlee Member Posts: 15
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    @Jamie Hall we are a little south of Poughkeepsie, NY

    I have multiple proposals from 5 local contractors for this job, from all the different times I changes the requirements :-( To keep things simple, I went back to the original proposals I received, before I started complicating things. I think this might be the best way to proceed.

    For the heat pump, three of the five bid a Mitsubishi MXZ-SM48NAMHZ, with a 30K BTU attic air handler. These three contractors are all proposing a 9k BTU wall mount for the larger of the two lower level rooms. Two of the three are recommending the same 9K for the smaller room, while the third is recommending a 6K wall mount.

    The other two bids:
    Daikin 4MNL36, with a 15K BUT attic air handler and 2 x 9k wall mounts

    Carrier 38MGHBQ, with a 36k BTU attic air handler, a 12K wall mount for the larger lower level room, and a 9K for the smaller

    FWIW, the heat pump is replacing a Carrier Puron central AC unit I've had zero problems with in 24 years (other than a couple of run-start capacitors), so I might be a bit biased for Carrier, but cannot say how their legacy equipment reliability compares with their heat pumps.

    I was able to find the COP and other data online for all these systems, but am not certain how to interpret them: I used the mixed (ducted and ductless) figures for all the systems

    Daikin 4MXL36
    SEER EER HPSF COP
    19.3 11.75 10.15 3.88 (assume 47 degrees, no values found for other temps)

    Mitsubishi MXZ-SM48NAMHZ
    SEER EER HPSF COP
    19.5 11.8 10.5 3.6(47 degrees), 2.18(17), 2.2(5)

    Carrier 38MGHBQ
    SEER EER HPSF COP
    22.6 12.8 10.75 3.96(47), 2.85 (17), 1.85(5)

    For heat, two of the contractors bid Peerless WBV-03 boilers, one bid a Lennox 0WB86, one bid a Crown 3-pass, and one gave me two options: Biasi 10/4, and EK 1 Frontier. Again, the existing boiler is a Peerless, so given how long it has lasted I may be biased towards them.

    Upon looking over all these bids collectively for the first time, the Daikin bid stands out in that the attic unit is about half the size of the units the other contractors quoted. I have at least heard of most of the other brands quoted, other than Biasi.

    Any thoughts on 1) how I should interpret the COP, etc figures, or are they close enough that the differences don't matter that much? 2) the brands? I have a completely uninformed impression that Mitsubishi is the "gold standard" of mini split heat pumps, which may or may not be true. I've also heard that Carrier mini-splits are actually manufactured by an off-shore company called Midea.

    Thanks in advance for any guidance or tips. This is a big purchase and we want to make the best choice we can. I understand that the installer can make all the difference. I've dealt with two of these companies for over 20 years with no complaints, and the other three all have good recommendations as far I can tell, assuming you can trust the reviews you see online (which you can't always).
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
    edited April 21
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    1. The COPs are pretty similar. To demonstrate: 

    to compare $/mmbtu: $/kWh * 293 / COP for the heat pumps. So less than a 10% difference between the most and least efficient at 47F at $.25/kWh ($18.50 vs $20.35). I obviously do not know what you pay for electricity, this is a ballpark. 

    Oil: $/gallon x (1,000,000/138,000)/COP

    so at $4.25 a gallon and 82%, it’s $37.55/MMbtu. 

    2. Brands aren’t as important as installer. Also, make sure the sizing makes sense: 30,000 Btu for a 1000 sqft second floor seems extreme. They modulate some, but can’t overcome immense oversizing. 

    How many oil gallons do you use per year? 
    And we’re sure the existing boiler needs replacement?
  • wlee
    wlee Member Posts: 15
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    Oil usage is a bit tricky. We have a small wood burning stove that we used extensively during the past two winters that actually provided a lot of our heat during the coldest months. If I go back to the 2021/22 heating season, where we did not use the wood stove nearly as much, I see we used about 680 gallons of oil from June 2021 through September 2022. This is for both heat and DHW, for two people.

    The current boiler and indirect tank are working with no issues We have the boiler serviced every year, so aside from it being over 40 years old, there is no pressing reason it has to be replaced. The same is true for the current central air unit. The motivating factor for me is I'm hoping to retire in the next couple of years. Given the age of the two units, I see myself having to replace them eventually. I would rather do it while I am working than afterwards. This is also why I didn't mention the wood stove earlier; as I get older it will not be as much fun to stack and carry cords of firewood around the yard is it is now, and so it is likely I won't be using it as much to offset the true heating requirement.
  • Roger
    Roger Member Posts: 333
    edited April 22
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    @wlee , you’re in a great position to install a practical and versatile hybrid system as you move into retirement, and I really like your approach.

    A couple things to consider:

    Electricity prices have been increasing rapidly in New York and New England, and they will likely continue to do so going forward. By providing high-efficiency heat pumps and a high-efficiency boiler, you can switch to the best system for your needs at any time in the future.

    There is a substantial difference in oil consumption between and Energy Kinetics boiler and all others, whether it is just for hot water, or for combination heat and hot water. Thermal purge, or energy recovery, plays very big role in capturing the energy used in the boiler and making sure it performs at  peak efficiency whether it’s for a small load like hot water, or steady state heating in the dead of winter.  Based on the Dept of Energy’s BNL report, we typically save 60 to 100 gallons of oil per year on hot water alone vs other boilers with indirect tanks. 

    Just like the AFUE rating for heat and hot water boilers is not very accurate, it’s widely established through NREL and other organizations that field performance of heat pumps is about 20% to 30% less than the heating COP ratings indicate (adjusting for this, a ballpark field performance number for a good heat pump at near freezing temperatures is a COP of 2.3 to 2.5).  Centrally ducted heat pumps also have additional substantial duct losses. Likewise, you should use the efficiency ratings from the BNL report to compare boilers.

    Typical cast-iron boilers run at higher efficiency during the coldest weather, but run at much lower efficiency in the spring and fall and for hot water only applications in the summer.  So you could install a lower efficiency boiler and only plan to use it in the cold weather, but then you likely would want a better option for efficient hot water that you can use with a generator (if you have a tank, that may last a day or so without reheating).
    Heat  pump water heaters “pump heat” from the conditioned space into the water tank, so if you were to use one while you were using heat pumps to heat your house, they work against each other to some degree. The net effect is that they are about 25% more efficient than an electric water heater when used in a heat pump heated home application during heating months.

    If your indirect tank is relatively new, you could keep it and connect it to a high efficiency boiler, although Energy Kinetics boilers cannot purge nearly as well to an indirect tank with a coil as they can with an indirect tank with a plate heat exchanger.

    I know this as much to consider, but you should make an informed decision to suit your needs and that will require a well thought out analysis.

    Best,

    Roger

    President
    Energy Kinetics, Inc.
    MikeAmannErin Holohan HaskellEdTheHeaterMan
  • SuperTech
    SuperTech Member Posts: 2,188
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    @wlee the company I work for is an EK dealer in Dutchess county. PM me for details, we would be happy to provide you with an estimate. 
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
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    @Roger that BNL report is from 2007 correct? Has there been an updated report? Would you suspect the efficiency gap remains or have the competitors closed the gap some? 
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
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    @wlee

    For the heating load, here's a rough estimation of your heating loss based on the oil usage you reported. As you can see, you'll be around 30kbtu heat loss for the entire house, so no need to go overboard with the heat pump sizing since you will have a boiler that's significantly larger than 30kbtu installed in tandem.



  • Roger
    Roger Member Posts: 333
    edited April 22
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    Thank you, @Hot_water_fan .
    In summary, the basic conclusions in that report are as sound as they ever were.
    The report had heat and hot water boilers rated up to 95 AFUE (AFUE is more like peak efficiency calculated with about 120°F return temperatures); some models have increased to 96 AFUE, which is a minor gain. Oil boilers' minimum AFUE has increased from 84 to 86, so overall the typical new boiler AFUE is likely a few points higher than in the report. As idle loss is a primary factor in real efficiency and because it is not rewarded in AFUE (which is used for marketing), there has been very little progress in annual efficiency in that time - basically it costs more to lower idle loss, but there is not a marketing benefit from the boiler rating standard. There are more brands and models of 3-pass boilers, which sometimes reduce idle loss with better insulation than pin boilers, but go backwards with higher comparative mass and no thermal purge; overall 3-pass boilers have improved vs pin type boilers with hot burner doors. And tankless coil boilers are still the dominant product in the oil market, but they are low efficiency, have poor hot water quality, and are often noisy. The efficiency gap is live and well.
    Roger
    President
    Energy Kinetics, Inc.
    Hot_water_fan
  • wlee
    wlee Member Posts: 15
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    @Hot_water_fan thank you for the calculation. Our house faces south with full exposure to the sun. The upper floor is considerably warmer in summer than the lower, which is partially below grade and really would only need cooling on the hottest or most humid days. Our current AC unit is a Carrier 38TXA030, mated with an FV4ANF020 attic air handler. I believe these are 30k BTU units and have satisfied the cooling load for the upper floor with no problems for 24 years. It's not clear to me how the cooling numbers would translate for a heat pump, though. The dealers who quoted the Mitsubishi equipment seem to have sized closest to what I have now for AC, but I have no idea if the original 30k Carrier unit was oversized from the start.

    @Roger I like the EK units, but am struggling to reconcile the price difference with how I intend to use the system. One other thing that gives me pause is how DHW is done. The dealer who bid the EK said they used a heat plate exchanger to make DHW, which sounded to me a lot like a tankless coil. I had a coil in our old boiler for about two months after we moved into our house and hated it; one of the first HVAC jobs we had done was to replace the coil with an indirect tank, and I never looked back. This means the indirect tank is 24 years old, and like the rest of the HVAC system I haven't had any problems with it, but feel I should replace everything while I am still working.

    One other question: if the most efficient use of the heat pumps would be use them for heat down to about 20 F outdoor temperature, then switch to oil at lower temperatures, is there a device that will do this for me, perhaps with an outdoor temperature sensor or a "smart" unit connected to the internet to get temperature data?

  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
    edited April 23
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    The dealers who quoted the Mitsubishi equipment seem to have sized closest to what I have now for AC, but I have no idea if the original 30k Carrier unit was oversized from the start.

    Usually how it goes! I’d focus them on sizing the AC correctly - 30btu/sqft of cooling in NY is pretty absurd. A new house is typically 1000sqft per ton and that’s in hotter climates.


    is there a device that will do this for me, perhaps with an outdoor temperature sensor or a "smart" unit connected to the internet to get temperature data?

    yes, the installers can provide this. It’s vanilla.

  • Roger
    Roger Member Posts: 333
    edited April 23
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    Thank you, @wlee.

    If you have any specific questions, please give us a call at (800) 323-2066 or PM me.

    We absolutely agree with you about the poor performance and comfort of tankless coil boilers' hot water. The plate heat exchanger with a tank is the best way to make hot water for several reasons, and we specifically designed our heat and hot water systems to greatly outperform tankless coils for hot water output, temperature consistency, service, and of course efficiency.

    Here's why: On a System 2000 Frontier, the plate heat exchanger can take the full output of the boiler and make it into hot water, so a 40 gallon tank typically will be replenished in 12 to 14 minutes (much faster than comparable tanks with coils, too). The tank is heated from the top down, and water flows out the top of the tank to the fixtures, so if hot water is being produced, it is immediately available for flow to the fixtures; much of the tank can actually be cold and hot water temperature at the fixtures doesn't suffer. The tank thermostat then turns off the burner with a small reservoir of unheated water at the bottom of the tank - this almost perfectly matches the amount of heat that is left in the boiler. Our energy recovery stage pumps this remaining heat into the tank so the tank ends up fully heated and the boiler is cooled back down toward room temperature so no energy is wasted. The heat exchanger also has a non-stick coating (Sealix®), that prevents mineral build up, so they are long lasting and easy to clean.

    If you are considering the purchase of a boiler, a robust analysis would be to consider the payback on the differential in cost between a lower efficiency product and a higher efficiency product. It could very well be shorter, but if the savings pays for the cost difference in 8 years, that's a 12 1/2% tax free return on the investment - difficult to beat anywhere. Regarding heat pumps, from broad based studies and in our experience, many people turn their boiler on when the defrost cycles start on heat pumps (around freezing temperatures); this is also where carbon intensity of the grid is increasing steeply. That's also cost effective with fuel oil at $4.00/gallon and electricity at $0.25 to $0.30kWh (that's the energy equivalent of about $10 to $12/gallon of oil). Our boilers are also certified for use with B100 (100% biodiesel), which future proofs your investment.

    And finally, as @Hot_water_fan noted on the thermostats, it's vanilla. Backup heat for a hybrid system will call the boiler; this can come on with a temperature differential in your home, at a specific outdoor temperature, or when you manually switch the thermostat to emergency heat.

    Best,

    Roger

    President
    Energy Kinetics, Inc.
  • wlee
    wlee Member Posts: 15
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    @Hot_water_fan I reached out to one of the installers re: the A/C sizing. He confirmed he purposely quoted an air handler close to the size of my existing unit because my existing ducts were sized for a 30k BTU air handler, and there could be a problem if a smaller air handler was used with oversized ducts (something about freezing, possibly the air handler itself could freeze up under those conditions?).

    @Roger I'm giving the EK a second look. One common refrain I hear from installers who don't sell the EK is the controller board is a point of failure. I brought this up with the contractor who bid the EK Frontier 1 system; he told me in an emergency the EK can run without the board, albeit less efficiently. Is that correct? If the board went bad in the middle of the night, could I pop the board out myself to get the heat back on? Or does that require a service call? The EK dealer did say his service people could replace the board for a price I thought was very reasonable for the part. In fact, EK's own website lists the "trade price" for the board at very close to what the EK dealer mentioned, after the defective part was returned. Similar to a core charge when you have to replace your car battery. Another non-EK installer said that board would cost about 12x the "trade price" if it went bad. I'm guessing that's list for the board without returning the old one? But I would assume any EK dealer would have a supply of those boards on hand, and should only charge me the trade price for the part, or close to it, if it had to be replaced. Of course, if list is really that expensive, a service department might choose not to stock a lot of them to keep parts inventory costs down. This is definitely something to clarify before moving forward with an EK.

  • SuperTech
    SuperTech Member Posts: 2,188
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    Typically in our area heat pumps are sized for the heat loss of the home, when this is done then the system is sized properly for heating but oversized for cooling and can have problems with dehumidification. I prefer to see a heat pump installed sized for the cooling needs, with a properly sized furnace or boiler in place to meet the heating demand. The heat pump can be used during milder weather.

    You should have no worries about a EK boiler with domestic hot water production. I personally think the plate heat exchanger combined with the energy manager can't be beat. It's as reliable and efficient as you can get. You can also combine an EK boiler with an indirect if you want, but you give up some efficiency with that setup. The system 2000 is absolutely nothing like a tankless coil boiler! I service dozens of them in Dutchess county and no one ever complains about anything. Customers really love those boilers, it's the only boiler that I see people smiling when I ask them about it.

    Roger
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
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    He confirmed he purposely quoted an air handler close to the size of my existing unit because my existing ducts were sized for a 30k BTU air handler, and there could be a problem if a smaller air handler was used with oversized ducts (something about freezing, possibly the air handler itself could freeze up under those conditions?).


    Ha!

  • wlee
    wlee Member Posts: 15
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    @SuperTech @Roger when I see a water tank in the EK brochures, I was assuming it was an indirect tank, similar to what I have now (where a separate heat zone is piped into it to heat the DHW). Reading your comments, it sounds like that's not accurate - is it more along the lines of a storage tank for DWH, as opposed to a device that makes DHW (like an indirect)?

  • wlee
    wlee Member Posts: 15
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    @Hot_water_fan @pecmsg could you please expand on your comments a bit? Are you saying there shouldn't be an issue using a smaller air handler with larger ducts? I'm trying to understand as four of the five dealers submitted bids for a 30K BTU or higher air handler. Only one bid a 15k. Thanks.

  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
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    Yes, simply the installer made that up. You’ll have plenty of air flow and the coil won’t freeze. There’s no such thing as “sized for 30kbtu”. You size ducts for airflow at a pressure. You’ll see 30kbtu air handlers in all sorts of ductwork sizes. In this situation, you’ll have higher airflow and lower pressure. That’s fine! It’ll be quieter and cost less to move the air.

    They sized 30kbtu units because they saw what was there and matched it. They did not do the work to size correctly, except for the 1 installer.

    bburd
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,886
    edited April 24
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    when I see a water tank in the EK brochures, I was assuming it was an indirect tank, similar to what I have now (where a separate heat zone is piped into it to heat the DHW). Reading your comments, it sounds like that's not accurate - is it more along the lines of a storage tank for DWH, as opposed to a device that makes DHW (like an indirect)?

    An indirect doesn’t directly heat DHW, hence the name. The boiler heats the water and stores it in the tank. EK uses indirects. The EK difference is that the heat exchanger is outside of the tank while others put it inside the tank. It’s an indirect either way.

    A standalone heater directly heats the water without a boiler.

  • pecmsg
    pecmsg Member Posts: 4,895
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    Coils freeze due to low air flow not high.

  • Mustangman
    Mustangman Member Posts: 113
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    One more opinion. First, I have sold Daikin, Mitsubishi and most recently am an LG dealer. A few things about Daikin you may not know. They started in Japan, which if you think about it, with their space limitations, Ductless quickly became popular very fast. If my memory serves me correctly, Daikin started in the early 80s. That gives them an edge as they have been at the ductless game a long time. Daikin grew into Austrailia, Europe, Asia, GBbut not in the US. ( Not sure what the Russians use ). Daikin wanted to get into the US market so they purchased another estabilshed company Goodman. That is why their footprint in the US grew so quickly.

    Daikin is a quality product and they stand behind it. I believe they were the first to offer 12 yr parts. You made mention of the size difference between air handlers. Here is why. The ductless people wanted to get into the ducted air market too. They started by offering mini air handlers. They go by Low static and High static units. They are currently becomming more an more popular. The low static ( 0.2 ) is just that. Its good for a few diffusers. After that, you have to bump up to High static 0.24 to .48. The newest concept is matching a full sized air handler with the mini split outdoor unit. I had a LG rep in my office a few weeks ago from his mouth " Our goal for the future is to push the full sized air handler matched with ductless outdoor unit. If the guy who's air handler was bigger, may not have told you some of the benefits of matching full sized AHUs with ductless.

    First was the ability to add strip heat to your air handler as emergency heat. That is one of the issues the ductless market has in the northern climates. Another is efficeincy 18 or 19 SEER is very costly if you were purchasing it in a normal ducted system. The system is a true DC inverter which allow it to ramp up or down depending on conditions.

    A few things on efficiency. We throw all these abbreviations around like HSPF and SEER and 90% of the folks have no clue what they are. SEER seasonal energy efficiency ratio. Simply put, how efficiently the unit take a KW of electricity and convert it to cooling BTUs. SEER is for the cooling side. HSPF heating season performance factor. This rating is similar to SEER as it is measured how efficiently does the unit convert KW to Heating BTUs. The higher the number, the more efficient. The HSPF is always lower than SEER.

    As for the oil boiler There are a few I like. You may not have heard of this company, Axman Anderson? I grew up playing sand lot football on their side yard. I know the owner Pete and he has personally come out on jobs with me. One is the biggest residential hot water heat job I ever did. This goes back almost 25 years now but he helped me design a large system that utilized 3 boilers and closely spaced tees. I had so many doubts about these tees and would water go where it is suppose to. A converion to gas and 2 different boilers the system side works flawlessly. For a cast boiler, more moderately priced Utica is my choice.

    It really boils down to this…. Fujitsu, LG, Mitsubishi and Daikin .. do you like Ford, Chevy or Toyota? They are all good and most of the time it comes down to what you like, any brand that has served you well? In case you missed it, I didn't include Dodge as a choice. Not a fan. Good luck

    Steve

  • Roger
    Roger Member Posts: 333
    edited April 24
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    Thank you for your consideration, @wlee - good questions all around.

    The trade list price on the manager after a core return is as shown on our website. This covers just about any manager replacement, with the exception being if it has been under water. A new manager is about 2.5x that price. Please tell your "12x the price" contractor to call us if they ever need technical support - we won't charge him for tech support or 12x for a manager.

    When we design our products, we have what we call a 2 AM test - can any tech get the boiler running at 2 AM with standard parts on a service vehicle safely for emergency heat? The manager passes this test as it can be bypassed by moving a pair of thermostat wires, providing power to the burner/main circulator relay, and manually opening zone valves; this should only take a few minutes and all the safeties remain fully functional. Or the tech could plug in a Service Board in place of the manager, which takes 30 seconds, to get heat and hot water back on and make the boiler run like an old cast iron boiler with heat and hot water; the tech just has to plug the manager back in to restore operation and energy savings. So heat is restored whether the heating professional has a spare part or not.

    Beyond that, Energy Managers are very reliable and have a 5 year part warranty and a lifetime protection plan (like a core return on a car battery as you described). Our boilers also have surge protection built in to protect all the components from power spikes and surges. We honor managers that go back to 1979 with the lifetime protection plan.

    To your question about the tank, it is a storage tank with an external heat exchanger. Again, this offers exceptional hot water production, hot water temperature quality, efficiency, and serviceability. From a technical standpoint, System 2000 draws cold water off the bottom of the tank and pumps it through the heat exchanger - this offers a big temperature difference vs the boiler supply temperature and delivers high output and high efficiency (thermal purge then pumps heat remaining in the boiler into the tank for an extremely high efficiency cycle). Compare that to a typical boiler and tank with a coil: as the tank heats up, there is a smaller temperature difference compared to the boiler supply water temperature, so the output drops as the tank heats and it's as if the boiler becomes more oversized vs the load (in a typical boiler/indirect system, the tank and boiler also finish hot, a boiler finishing hot is a waste of energy).

    Roger

    President
    Energy Kinetics, Inc.
    bburd
  • wlee
    wlee Member Posts: 15
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    I reached out to the installer who bid the 15k BTU Daikin air handler. As it turns out, I misread his proposal and he was actually proposing to install two 15k BTU air handlers, one at each side of the house, and removing the existing duct work and replacing it with new (note the Daikin dealer was not the installer who told me the air handler would freeze if a smaller handler was used with larger ducts). Both air handlers and both mini splits for the lower floor would be driven by the same outdoor unit. His quote was not that far from the others I received and not close to the most expensive. Lesson learned to go over these proposals more carefully before making a decision. The net is all 5 dealers were bidding cooling for the upper floor at 30k BTU or higher.

  • wlee
    wlee Member Posts: 15
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    I would also like to thank all the members who chimed in with comments, suggestions, and opinions. There is real value in this board for educating non-pros and consumers looking to make a large investment in their homes. I appreciate all the thoughtful advice.

    Erin Holohan Haskell
  • Greening
    Greening Member Posts: 10
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    See if you have any neighbors running new electric heat systems to get their opinions on heating performance and operating costs.

    We have used Japanese models in apartments in Southern Europe & Japan and thought they were pretty good, especially for cooling performance.

    A family member had an inverter system installed in New England and he could not dial in the heat this winter (and he was disappointed in the electricity use) so ended up turning back on the resistive heaters.

  • wlee
    wlee Member Posts: 15
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    We know someone who lives a few miles north of us who has Fujitsu mini splits installed throughout their home, which is similar to ours. They are cold climate units and were able to provide heat on the colder days of this past winter. I got the impression their electric bills were pretty high during the winter months, which is why I'm trying to set everything up for an automatic failover to the oil/hydronic at lower outdoor temps. For A/C, I guess I'm assuming a brand new heat pump system will not use more electricity than my 24 year old Carrier central A/C system does now. The mini-splits on the lower level would be new, but I really don't expect to use them much for cooling during the summer.

  • tim smith
    tim smith Member Posts: 2,765
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    a question for wiee, what are you paying for oil per gals and electricity per kw. This will also help in decision on balance point for switch over from hp to boiler. Also a proper heating and cooling load per floor is needed to help on proper size selection and to provide data for switch over. If boiler in good condition and primarily used for back up, I would stay with it. The a/c is near end of life and not a bad idea to replace.

  • tim smith
    tim smith Member Posts: 2,765
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    they will be more efficient than your old a/c. How noticeable, not too much. Heating costs in winter heat pump vs oil are depending on rates. Can give better idea once rates are stated and hopefully loads given.

  • wlee
    wlee Member Posts: 15
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    I have no heat load numbers from any of the installers. All are bidding a 30k BTU capacity heat pump system for the upper floor and between 15k and 18k for the lower. Currently paying $4/gal for heating oil, and a bit under $0.1171 per kWH for electricity.

    Hot_water_fan