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Please help me decide between traditional or mod-con replacement boiler

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Comments

  • Gordy
    Gordy Member Posts: 9,546
    This is where a modulating boiler can shine with Cadillac controls so long as the minimum suits the smallest zone you can lockout extra high end horsepower until absolutely needed. Provided the emitters can absorb the extra btus.
  • NY_Rob
    NY_Rob Member Posts: 1,370
    Perfect explanation Gordy!

    I keep my HTP UFT-80W locked at 60% of max fire (48K BTU's), but last winter when it went down to 2F here and windy I unlocked the fire rate so I could get 80K BTU's and at the same time tweaked the ODR curve to give 180F SWT at -2F. Between those two settings I was able to hit setpoint within a few hours even at night/windy/close to 0deg outdoors.

    Soon ad the cold snap was over, went back to 60% max fire and 150F SWT at -2F outdoors.

  • Rich_49
    Rich_49 Member Posts: 2,766
    edited October 2018
    Central Jersey is rather large . Where exactly is our OP ? Maybe I can recommend someone who actually knows what to do or look myself .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,455
    @Coldax congratulations on doing your homework. I think you will appreciate why a heat loss calculation is so important. 100-120k sounds a lot more reasonable for your heat loss. With 175 of baseboard you will be able to heat with moderate water temperatures which will save fuel.
    Gordy
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    I live near Red Bank NJ, and the design temperature around here is 14F, but sometimes it goes all the way down to 2F. In the years since I got my mod-con, it has done that only once or twice around 4AM to when the sun seriously came up. I have the reset curves increasing the supply temperatures all the way down to 0F. I used to have them stop at 10F.

    Downstairs is radiant slab at grade. Upstairs is fin-tube baseboard. It originally had 3 feet of baseboard in each room up there, but when I had the mod-con installed, I increased the baseboards to 14 feet in each room to keep the water temperatures down.
  • Coldax
    Coldax Member Posts: 12
    Rich said:

    Central Jersey is rather large . Where exactly is our OP ? Maybe I can recommend someone who actually knows what to do or look myself .

    I'm in Hillsborough, near Flemington.
  • archibald tuttle
    archibald tuttle Member Posts: 1,085
    Great thread, read the whole thing this morning when i came on to post some munchkin technical questions, but this choice of technology thing is big from my perspective.

    As an aside, Best suggestion anyone had is figuring out if there is an aesthetically acceptable affordable window treatment. That's a big window number and we don't have the square footage of glass or whether it is double paned, unless i missed that discussion. That can of stuff can quickly run up to the difference in boiler pricing you are talking about but maybe if a living room or master bedroom has excessive window area compared to others it would be worth considering and there is plenty of cool technology in that arena and even a minimal scrim can be effective. you don't need quilts or insulated shutters to get somewhere.

    I really like the technology in mod-cons but most homes built in the last century did not have heating systems designed to take advantage as many have already indicated. unless you want to add a lot of baseboard or have the possibility to install radiant (esp. in those high ceiling big window rooms) I would go traditional boiler. you can still use modest temperature setback control which principally reduces stack temperature and thus stack losses (as would a smaller installation you are already considering). there is also some slight gain when running lower water temperatures in terms of non emitter system losses, i.e. heat loss from the boiler itself and piping - although one must use some caution if no glycol and the piping was run in outdoor walls. But water temp. setback control (rather than thermostat setback) can be designed to yield longer demand cycles when its really cold reducing the chance of heating pipe freezing with typcial nighttime setback approaches. (this can be mitigated by pump cycling controls which it is insane to me aren't more commonly standard equipment in these settings).

    I also would consider simply going to an ondemand hot water heater when the bradford goes rather than an indirect assuming your thousand gallon tank at its lowest fill (if you aren't on a keep fill) probably could keep up with both boiler and on demand hot water heater calling. which is pretty much taken for granted if you are running 300K input now that a 175K boiler and 120 K on demand.

    I say this for several reasons, indirect tanks are literally more money than an on demand heater. Because of different operational goals it is easy to get condensing from an ondemand heater because the incoming water is so cold. That said, I think if you have the flu capacity you could also choose a non-condensing design and I have Takagi's that have been running 15 years with no service. The condensing ones by their nature are going to degrade even their corrosion resistant materials in the condensing area with deposits that will affect efficiency and could eventually lead to leak/failure of heat exchanger. But you completely lose passive losses with either approach.

    Which gets also to my theory of avoiding modcons if you are not taking serious advantage of the mod and the con and don't have a problem with a flu for conventional boiler (that said, modcons, running at higher temps without condensing totally push the limits of plastic venting which is whole nother problem). And modcons will have more service issues and be more costly to service and you may experience delays in getting parts depending on manufacturer and model. For all their technological sophistication which is as cool as it gets, the idea of spending double for a unit whose life will be half of a traditional boiler just gets under my skin. i think at the moment we are paying too much for people experimenting with bells and whistles.

    The other option is to buy a good used modcon like a munchkin ( I shouldn't say that because i want them all for myself and i might go to new jersey to pick some up, but i'm tipping my hand here). Since a lot of these are installed in circumstances where they don't condense much, you can find units in good shape that are being superceded not for unit failure, but someone got sold a new boiler, or merging aircon and heat, or went to bigger or smaller boiler, etc. It's easier to do this kind of stuff when install and service is inhouse as with our fleet of buildings. But a good contractor isn't making their money marking up the parts, but by fair price for their labor and delivering quality for the hours invested. And sometimes they have units they have taken out. Doing something like this using outside contractor, I would only choose a used unit that they are familiar, themselves recommend as reliable and they stock or have quick access to service parts.

    My 2¢. certainly worth all that. Good luck.

  • hot_rod
    hot_rod Member Posts: 22,024
    Fear of the unknown.

    I have a 20 year track record on mod con installations now, several at my own home. Not all will breakdown and need expensive, if any repairs.
    I agree yearly service is a good idea and an ongoing cost. Ideally cast boilers should be checked and serviced regularly, oil especially. A service contract is a win for installers and owners to assure things go as planned.

    Quite a few higher temperature fin tube type systems could run lower SWT 50% of the heating season, depending on where you live of course, a mod con owner and installer needs to embrace all the control features to optimize the efficiency and longevity.

    Mis-applications like we see here weekly really should not count against the product failures.

    I'll give you the PVC, that really needs to go away for high temperature mod con venting applications. Or the PVC manufacturers need to develop listings, testings and apply it to the product when used to vent byproducts of combustion.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    DZoro
  • Gordy
    Gordy Member Posts: 9,546
    edited November 2018
    I’m not anti mod/con, but they are added cost over a conventional boiler, depending on brand, and controls. For some people that is a considerable extra expense. I just believe all aspects of owning one in the back end after installation needs to be made clear.

    Since ci boilers are a bit more forgiving, and not every installer hangs out at the wall, or can read the manual let alone look at plenty of illustrations I think the bad installs should count. Not the fault of the boiler by any means, but it is extra risk in not finding a compitent installer.
  • hot_rod
    hot_rod Member Posts: 22,024
    Gordy said:

    I’m not anti mod/con, but they are added cost over a conventional boiler, depending on brand, and controls. For some people that is a considerable extra expense. I just believe all aspects of owning one in the back end after installation needs to be made clear.

    Since ci boilers are a bit more forgiving, and not every installer hangs out at the wall, or can read the manual let alone look at plenty of illustrations I think the bad installs should count. Not the fault of the boiler by any means, but it is extra risk in not finding a compitent installer.


    A fair assessment, KISS appeals to many customers still.

    Present the options, pros and cons, the customer gets to decide.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Canucker
  • BennyV
    BennyV Member Posts: 49
    @EBEBRATT-Ed That's quite true about MA and the gas distribution system. You are dependent on "the grid" so to speak. In the OP's situation, LP is more reliable and stable than even fuel oil, as it can stay for very long periods of time in a tank without degrading, and it is a local, pressurized supply of gas.

    Another interesting side note is that meter fees on NG are significant. When you factor that in, you have to use quite a bit of NG for it to be significantly cheaper than LP on a yearly basis, even though BTU for BTU it's something like half the price.

    With Oil, you've still got a dirty, nasty fuel supply, and a dirty, nasty burner that can't modulate. With gas, things are a lot easier, as you've got much cleaner combustion, modulation, and condensing.

    @Gordy Maybe on NG with a small house. With a large house on LP, the modcon is going to win by a huge margin, especially when you factor in future volatility of LP prices.

    @Coldax Those are still too big. Look at something like a 10-150 or 15-150 heating boiler, not a combi. Navien has some of the higest TDRs, but there are a bunch of manufacturers that have 10:1 TDRs for a 15-150 boiler. Lochinvar is very good, arguably higher quality than Navien. Some people hate on the Naviens, others like them. Lochinvar is widely regarded as a great boiler. They are US made in TN if you care about that sort of thing.

    If you want hot water off the boiler down the road, tie in an indirect. If you really want tankless, you could do a separate tankless unit down the road and have better reliability and performance out of the two separate units. There are also condensing tank units that are very powerful. All would be better options than a combi. You've got 3 or 8 years left on the existing water heater depending on how it was rated originally, so just stick with that for now.

    @Gordy The design load is roughly 15% higher than what the house actually needs anyway. Design assumes no electric usage in the house, no thermal capacitance, and it assumes grandma has the heat blasting at 70. Further, it has some fudge factor in it. Take away those four factors, and recovering from a setback shouldn't be an issue.

    Further, in the OP's situation, the design load is about 120k, which would size to a Navien NHB-150, which is a 10-150 boiler, so it's got the whole range to handle the smallest zone at lower temperature, up to starting up the whole house from a setback on a design day with no issue at all. Realistically, the OP needs a bit shy of 100k to maintain at design, so the NHB-150 would be quite comfortable. With ODR and modulation, it will actually provide better comfort than the existing boiler AND be way more efficient.
  • Gordy
    Gordy Member Posts: 9,546
    @BennyV

    When a homeowner does their own heatloss I caution.

    Yes heatloss programs are padded. That’s for a reason. There are large differences across different programs.

    Deep setbacks can get you into trouble at below design conditions. Seen it on here plenty. Having enough boiler is only part of the equation. Having enough emitter is the rest of the equation.

    I’m not a fan of setbacks unless it’s a huge loose envelope, or extended periods of vacancy. If the over night setpoint drops a couple degrees is it really even worth it? Allowing the mass of the envelope to cool then reheat is near same energy.

    The OP has 90 windows. Anderson 400’s. Part of the glazing has no window treatments. That’s a huge loss, and gain.
    DZoroBrewbeerRich_49
  • Gordy
    Gordy Member Posts: 9,546
    The HTP UFT 120 is a 10:1 TDR which will modulate down to 12k. That boiler is an excellent value mod/con there’s been plenty of people installing them with excellent results. The tdr should be low enough to accommodate any zone most of the winter with out short cycling. You can also plumb it from the top, or bottom, or both.
    BennyVRich_49
  • Gordy
    Gordy Member Posts: 9,546
    As far as Navien I can say there have been plenty of issues posted on here.
    BennyVRich_49
  • archibald tuttle
    archibald tuttle Member Posts: 1,085
    hot rod said:

    Fear of the unknown.

    I have a 20 year track record on mod con installations now, several at my own home. Not all will breakdown and need expensive, if any repairs.
    I agree yearly service is a good idea and an ongoing cost. Ideally cast boilers should be checked and serviced regularly, oil especially. A service contract is a win for installers and owners to assure things go as planned.

    Hot (can i call you hot . . . ?),

    so i've been in the mod and con worlds for about that long and the low mass world for maybe 20 years longer than that, but i'm just entering the mod con world - is it the best of all possible? My maintenance experience has just been markedly different between atmospheric gas, even power burner gas and these various low mass boiler implementations.

    My experience is that all low mass boilers will breakdown and need repairs because of control and combustion technologies - esp. but not exclusively in condensing circumstances efficency is compromised without tedious cleaning and heat exchangers may fail from corrosion. . although my understanding is the fire tubes which i don't have any running are better than water tube approaches (and lower head loss). But they cost like they are better . . .

    Now I pride myself on not being scared away by effective efficient technology and so I have paid the price both in parts costs and the opportunity costs of studying the systems I install because I need to know as much to run and install a couple as does someone who adopts a platform and installs a couple hundred. It is actually as much the control and safety environment that must be constantly maintained (kind of like the problem with emissions controls on cars) (although again a friend of mine reports less control issue generally with TT prestige so maybe I'm am wrongly extrapolating this previous low mass experience to all manufacturers).

    I can't imagine sustaining the cost to a homeowner to install and run some of these systems. I had to give up on endurance boilers. Really cool early modulating technology but I ended up in control and peripheral problems that even the highly engaged tech support from laars or waterpik or whatever it is this week literally could not solve. That is uncharacteristic of forerunner products from heatmaker which had their tedium but there was never something i couldn't fix.

    You might point to a line I haven't experienced that has a better maintenance history and i'm all ears, but my experience from Paloma Paks to heatmakers has been that the good old-fashioned cast iron technology is just plain more foregiving and reliable. It's easy going on pumping, can often thermosiphon a bit if a pumps is out. Aside from a thermocouple or thermopile every 5 to 10 years and a pump cartridge, i have done next to nothing on atmospheric gas - i know i could combustion test and adjust regulators and i'm actually starting to do that as a i rotate through the fleet, but the point is that they are forgiving in this arena as well. And 20 years of power burner conversion of oil units has produced very few maintenance issues as well.

    Yes, there is a potential fuel cost savings, but reliabilty, capital cost and maintenance convince me that the only reason to go mod-con in our centuries old housing is if you can design the installation and control to obviate the need for masonry chimney where unlined chimneys can eventually manifest challenges that favor low temp plastic venting. Even there, the industry has struggled to standardize and designs often don't result in stack temperatures truly appropriate for the venting materials (esp. with indirect DHW and primary secondary piping).

    Not only the maintenance of modcons puts me off, but the cost premium. Just seems like silly money to me. I just feel like there is too much cost wrapped up in the flash and marketing that don't contemplate the difficulties of taking advantage of features begin offered to justify the price, and that is compounded by constant redesigns and control changes that mean that they never sell enough units within a particular engineering framework to bring the cost down. (and that the complexity and applications issues could also ratchet up liability costs inherent within designing in this space, although i don't have statistics on that, it is just my instinct). Without discussing the price of any specific unit or distributor, I just can't figure how it went from a grand to over three per modest size unit.

    An ironic exception here is scorched air, with return temps of 70 degrees, nothing condenses like scorched air and with entry level condensing technology noticeably under a grand, i don't mind considering these furnaces as decade lifespan consumable items. Furnaces always were more consumable than cast iron. I don't have the length of experience to say how much condensing will reduce life span vs. standard furnaces, but at the low prices i'm nowhere near as put off condensing in forced air as in hydronic baseboard. Should have asked the OP if he has central air, because he could consider bringing his heat onto the ducts.

    Bottom line is, in the vast majority of our standing housing stock, if you have a chimney in halfway decent shape, your money is better invested in improving the envelope than in buying modcon technology in my experience. While in new housing with radiant emitting design and ground up insulation and envelope detail, and often without masonry flus, modcons are a perfect fit.




    SuperTech
  • hot_rod
    hot_rod Member Posts: 22,024
    I can't or won't argue with that. Use the technology you are comfortable with and your customers trust you to install and maintain.

    Certainly the best heating upgrade would be the building envelop first, spend $$ if it is a drafty, poorly insulated old building.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • BennyV
    BennyV Member Posts: 49
    Gordy said:

    @BennyV

    When a homeowner does their own heatloss I caution.

    Yes heatloss programs are padded. That’s for a reason. There are large differences across different programs.

    Deep setbacks can get you into trouble at below design conditions. Seen it on here plenty. Having enough boiler is only part of the equation. Having enough emitter is the rest of the equation.

    I’m not a fan of setbacks unless it’s a huge loose envelope, or extended periods of vacancy. If the over night setpoint drops a couple degrees is it really even worth it? Allowing the mass of the envelope to cool then reheat is near same energy.

    The OP has 90 windows. Anderson 400’s. Part of the glazing has no window treatments. That’s a huge loss, and gain.

    True, you do need to account for emitters. In the OP's case, there are more than enough emitters, roughly 160k worth.

    Setbacks can still save a bit, but setbacks just aren't that big. Even if you've got the heat cranked to 65 during the day, at near design conditions, I would never go below 55 at night with a well built house, 60 in a less well built house or where you've got piping in outside walls and such.

    I think the one situation where setbacks would make a lot less sense is with indoor reset. If you can indoor reset your hardest to heat zone with a modcon and keep it at constant temperature, it will probably be more efficient and more comfortable.

    Of course that's all for combustion. You get into heat pumps of any type, and setbacks can be a detriment to efficiency as they like to run continuously in even moderately cold weather.
  • BennyV
    BennyV Member Posts: 49

    Bottom line is, in the vast majority of our standing housing stock, if you have a chimney in halfway decent shape, your money is better invested in improving the envelope than in buying modcon technology in my experience. While in new housing with radiant emitting design and ground up insulation and envelope detail, and often without masonry flus, modcons are a perfect fit.

    Mod-cons are better in older housing stock, as there is more room to improve the envelope, making the radiation oversized, and you can drop the reset curve accordingly and stay in the condensing zone longer. There's just no good argument for CI given the modcon technology out there. If you want a ton of mass, then get a boiler with a ton of mass, it can still be a modern modcon, not some archaic CI boiler. CI is the territory of oil, which is another relic from another era.

    Further, new construction shouldn't need combustion. If it does, it is poorly built garbage. Modern good building practices are heating entirely with small inverter heat pumps, since their design loads are in the low- to mid- single digits per square foot. There's about a million and one approaches to modern good building practices, but you've got the traditional 2x6 with a layer of rigid foam and OSB on the outside, a 2x8 variation of that, the double wall construction method, and you've got various combinations of foam, cellulose, and fiberglass that make a much tighter envelope than older buildings ever had. In a well built modern house, you simply can't do radiant heating, as it would overheat the structure, so you're looking at various ways of distributing heat from a heat pump, be it high-wall cassettes, in-ceiling cassettes, ducted ductless, or a full blown air handler.
    Rich_49SuperTech
  • Gordy
    Gordy Member Posts: 9,546
    The great thing about hydronics is you can use multifaceted sources to heat the water. Not so much with a straight electric system. Your only alternative is PV solar. The grid goes down that’s it :)
    BennyV
  • archibald tuttle
    archibald tuttle Member Posts: 1,085
    bennyv

    i'll bite. what is your high mass condensing boiler?

    from what i can see, high mass is generally obtained by pairing a mod-con and a buffer tank so that the system costs 4 times a simple cast iron boiler instead of 3 times . . .

    i would agree that in the area of potentially useful investments, expanded radiation could be up there but it ain't like they give that away and in an older house where radiation is already installed at whatever ratio was appropriate to the heating elements of the time, i'd still invest in the envelope first.

  • BennyV
    BennyV Member Posts: 49
    Gordy said:

    The great thing about hydronics is you can use multifaceted sources to heat the water. Not so much with a straight electric system. Your only alternative is PV solar. The grid goes down that’s it :)

    If the power goes out, anything other than a gravity hot water gas boiler with a standing pilot is going to need electricity to run. For existing homes, that is a big advantage, as you can run the boiler and pumps, air handlers, furnace, etc, off of a small portable generator. Most houses today should retain a gas boiler or furnace alongside heat pumps for near-design conditions, or for power outages with a small generator.

    For new construction that is constructed to good building practices, they will hold the heat for a day or two without heat, even in cold weather. If a generator is desired, which is still a good idea, a modest standby generator could run a heat pump. Even a small portable generator without a transfer switch could run one or two space heaters and heat the whole house without any trouble at design conditions.
  • archibald tuttle
    archibald tuttle Member Posts: 1,085
    BennyV said:



    If the power goes out, anything other than a gravity hot water gas boiler with a standing pilot is going to need electricity to run.

    atmospheric gas steam powerpile does pretty good on its own but folks aren't likely to revert so low demand electric in aid of gas combustion is handy for power outages.


  • BennyV
    BennyV Member Posts: 49

    bennyv

    i'll bite. what is your high mass condensing boiler?

    from what i can see, high mass is generally obtained by pairing a mod-con and a buffer tank so that the system costs 4 times a simple cast iron boiler instead of 3 times . . .

    i would agree that in the area of potentially useful investments, expanded radiation could be up there but it ain't like they give that away and in an older house where radiation is already installed at whatever ratio was appropriate to the heating elements of the time, i'd still invest in the envelope first.

    HTP has some really interesting products that are very innovative in terms of combined heating and hot water, along with thermal mass. The Viessman 300 is a more traditional boiler, and is probably the finest boiler you can buy, although it costs half a fortune.

    A CI gas boiler is not comparable at all to a modcon with a buffer, the former of which will short cycle with small loads, the latter of which will not.

    You wouldn't change the radiation itself, you would improve the envelope. 1950's and earlier houses were poorly insulated and had poor performing windows, so when those issues are fixed, the radiation will become substantially oversized, and the reset curves can be dropped accordingly.
  • Rich_49
    Rich_49 Member Posts: 2,766
    BennyV said:

    Bottom line is, in the vast majority of our standing housing stock, if you have a chimney in halfway decent shape, your money is better invested in improving the envelope than in buying modcon technology in my experience. While in new housing with radiant emitting design and ground up insulation and envelope detail, and often without masonry flus, modcons are a perfect fit.

    Mod-cons are better in older housing stock, as there is more room to improve the envelope, making the radiation oversized, and you can drop the reset curve accordingly and stay in the condensing zone longer. There's just no good argument for CI given the modcon technology out there. If you want a ton of mass, then get a boiler with a ton of mass, it can still be a modern modcon, not some archaic CI boiler. CI is the territory of oil, which is another relic from another era.

    Further, new construction shouldn't need combustion. If it does, it is poorly built garbage. Modern good building practices are heating entirely with small inverter heat pumps, since their design loads are in the low- to mid- single digits per square foot. There's about a million and one approaches to modern good building practices, but you've got the traditional 2x6 with a layer of rigid foam and OSB on the outside, a 2x8 variation of that, the double wall construction method, and you've got various combinations of foam, cellulose, and fiberglass that make a much tighter envelope than older buildings ever had. In a well built modern house, you simply can't do radiant heating, as it would overheat the structure, so you're looking at various ways of distributing heat from a heat pump, be it high-wall cassettes, in-ceiling cassettes, ducted ductless, or a full blown air handler.

    While requiring a whole lot of attention to detail and really having a good grip on building science and physics , not enough possess this knowledge , your theory that newer , very well built homes cannot be radiant heated or efficiently use combustion is FALSE .

    There are a few who have been shattering that theory for quite some time now . You're on the right track but have much to learn BennyV .

    How you use the energy you consume is much more important than what fuel you use . A major portion of the electric grid still uses fossil fuels for generation .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
    GordyCanuckerSuperTech
  • Gordy
    Gordy Member Posts: 9,546
    I will add, what more can get the most efficiency possible out of a condensing boiler than a properly designed envelope, and a radiant panel emitter.
    Rich_49Canucker
  • archibald tuttle
    archibald tuttle Member Posts: 1,085
    edited November 2018
    BennyV said:



    A CI gas boiler is not comparable at all to a modcon with a buffer, the former of which will short cycle with small loads, the latter of which will not.

    You wouldn't change the radiation itself, you would improve the envelope.


    I'm saying a CI is analogous in ways to a modcon and a buffer, not comparable in all ways. But CI won't short cycle as much with a wide differential with return allowance down to 140. but cycle parts wear are less for starts on a CI, especially atmospheric. i don't disagree which i might prefer if money were not an issue.

    and when gas quadruples every % of efficiency you can wring out of it is going to seem more worthwhile and more capital investment and maintenance to acheive that would be merited. right now, i don't see that the paybacks are there.

    ah, i get your point now about envelope work enabling existing radiation to work at lower temps. thumbs up to that. I would just do it before i got a mod con and if i only had money to do one of the other i'd do the envelope, set a wide differential on my CI and off to the races.
    BennyVGordy
  • BennyV
    BennyV Member Posts: 49
    Rich said:

    While requiring a whole lot of attention to detail and really having a good grip on building science and physics , not enough possess this knowledge , your theory that newer , very well built homes cannot be radiant heated or efficiently use combustion is FALSE .

    How would you set up a radiant system for a 1700 square foot house with a design load of 8500 BTU and do air conditioning? The only logical way is an inverter heat pump with electric baseboard backup if required by code. Even geothermal is a waste of money on modern well built houses where the design loads are under 5 BTU per square foot. Further, everything has to be electrified to get to net zero, otherwise you're still spending money burning stuff.
  • BennyV
    BennyV Member Posts: 49

    ah, i get your point now about envelope work enabling existing radiation to work at lower temps. thumbs up to that. I would just do it before i got a mod con and if i only had money to do one of the other i'd do the envelope, set a wide differential on my CI and off to the races.

    Yeah, if I had an existing CI boiler that was in good shape, and a poor envelope, I'd definitely tackle the envelope first and set myself up for success with a modcon down the road when funds allowed. I'd tackle insulation and air sealing first, and then look at the cost/benefit on doing windows versus mechanicals, since both are way more expensive than insulation and air sealing.
  • Rich_49
    Rich_49 Member Posts: 2,766
    BennyV said:

    Rich said:

    While requiring a whole lot of attention to detail and really having a good grip on building science and physics , not enough possess this knowledge , your theory that newer , very well built homes cannot be radiant heated or efficiently use combustion is FALSE .

    How would you set up a radiant system for a 1700 square foot house with a design load of 8500 BTU and do air conditioning? The only logical way is an inverter heat pump with electric baseboard backup if required by code. Even geothermal is a waste of money on modern well built houses where the design loads are under 5 BTU per square foot. Further, everything has to be electrified to get to net zero, otherwise you're still spending money burning stuff.
    Let's agree that GeoThermal is NEVER a waste since GeoThermal requires no equipment to provide heat as the heat is in the fluids you are using . I would think that you meant to reference a ground source heat pump ?

    NetZero homes do not require electrification either . The only criteria to achieve Net Zero , " they produce as much renewable energy as they consume over the course of a year " .

    Maybe another discussion should be started about these types of subjects and we get back to this posters question .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • BennyV
    BennyV Member Posts: 49
    Rich said:

    Let's agree that GeoThermal is NEVER a waste since GeoThermal requires no equipment to provide heat as the heat is in the fluids you are using . I would think that you meant to reference a ground source heat pump ?

    NetZero homes do not require electrification either . The only criteria to achieve Net Zero , " they produce as much renewable energy as they consume over the course of a year " .

    Maybe another discussion should be started about these types of subjects and we get back to this posters question .

    Yes, GSHP, not geothermal straight out of the ground like in Iceland.

    You can't practically or economically get to net zero if you're buying propane or gas and giving away your extra power to the electric company. They have to be all-electric so that you net meter everything out.
  • SeeBuyFly
    SeeBuyFly Member Posts: 2
    As a homeowner, we picked a mod con because we didn't like how hot the radiators got whenever the hunk of cast iron kicked in. Turns out we had excess radiation (old house), so we could use lower temperatures.

    Savings...we haven't seen any that will pay for the boiler during this century. And there are more things that can and do go wrong.

    But it's really nice not to feel intermittent high heat from the radiator, yet the house is always just the right temperature. Just need to set the curve as low as possible, through experimentation, ignoring the installer's insistence on setting it high to cover his ****. And once it's set as low as possible, there's no possibility of using thermostat setbacks to "save" money. But the comfort is worth it.
    GordySuperJBennyVWintersInMinne