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boiler design and zones

245

Comments

  • TerrS
    TerrS Member Posts: 172
    @JakeCK the interesting thing about the inflation reduction act from what I have read they are credits, at least in my tax bracket. So you have to pay taxes to get thr upto 30% credit back on taxes owed. But 30% is 30% so an option I am looking at.
  • JakeCK
    JakeCK Member Posts: 1,356
    There is the rebate which is applied by the installer when you pay for the install. And then there are the tax credits. Also you can often carry over unused tax credits the following tax years. I have a little bit of my tax credit left from my solar panels last year to apply to this year for example.
  • hot_rod
    hot_rod Member Posts: 22,024
    Mini splits have a place, but they sure can ugly up a house :) with a maze of scabed on line sets. A 10 year throw away product that can be a disaster to clean, when the inside units need service.
    If you have a ducted system, stay with that.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    JakeCKSuperTech
  • WMno57
    WMno57 Member Posts: 1,250
    HEEHRA
    10 year program.
    A few details are out.
    Many more details coming soon from the DOE and your State's Energy Programs.
    Stay tuned to the Heating Help HEEHRA thread.
    https://forum.heatinghelp.com/discussion/189316/heehra#latest
    I DIY.
  • TerrS
    TerrS Member Posts: 172
    edited October 2022
    @hot_rod my house is 1903 vintage, coal furnace converted to hot water way back when. So I have 0 cost effective solutions besides the 10yr warranty mistubishi mini split are, what I would install. With ceiling cassettes. Nice clean sight lines and no ugly wall units.

    I have access thru the interior of my house if I would decide to do the bedrooms and would do new construction ceiling cassettes so again no ugly wall mounts.

    The upstairs bedrooms would still use window a/c units and boiler heat.
  • TerrS
    TerrS Member Posts: 172
    @hot_rod that's great information you provided, thanks, but sadly it doesn't work in my house and my current single pipe configuration.

    The current panel radiator solutions are Runtal, Buderus, ecostyle, Penscotti and Bisque. And if you look at the BTUs. They are only Slighly higher, like 300-500btu in total heat given over total length/height and all require 180degree water, which then defeats the mod-con design requirements to lower water temperature. There are no capabilities of adding more radiators or fins unless I rip down my house/walls and start again.

    The $800 cost per 71" Buderus radiators can't be justified thru out the house.

    As mentioned before. I have looked at my aquasmart and water temperatures and it's running 180degree for at least 20 days a month in Jan and February and no less than 160 other days. This is one feature I do like about the Beckett is the history feature of the past 7 heat cycles. I understand design days. But after 31yrs of living in this house, someone made some gross miscalculations or maybe didn't care back in 1950.

    All the recommendations for house envelope and making it more air tight all come at a cost. Adding to that ROI, of let's say an extra $100 month run cost of an 85% non-con boiler, compared to my 78% boiler still puts me way ahead, cost wise until year 11.

    So until a better radiator or newer technology comes out for slant-fin retrofits. I don't see the buy back of a 95% boiler.

    However as others have mentioned, if I installed a 30k btu mini-split at least for my first floor and basement, and then downgraded my boiler from 150k to 80k btu's. That cost is way more manageable and makes my house warmer.

    Then I can focus the boiler to the upstairs requirements.
  • JakeCK
    JakeCK Member Posts: 1,356
    There is simply no way your heating system requires 180F all season long if it is capable of heating your house comfortably at design conditions. I'm sorry to tell you this but you are simply mistaken. You may see 180f as the system cycles but that is not what is required.
    KC_Jones
  • TerrS
    TerrS Member Posts: 172
    @JakeCK just curious, I didn't say all season,  but Jan and Feb yes. I have sat and watched the boiler temperature Guage and it goes to 180 on most days. I know you don't believe me. But in my other thread when the l8124 was set a 165-170, we all froze in this house. So call it what you want but that's reality.

    The issue here is you are using today's standards with a 1950 design. Just taking into what @hot_rod has explained to me, a house with 2000 sq and only 104ft of fins. Is way undersized. Which is why I need the hotter consistent water.
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,823
    @JakeCK just curious, I didn't say all season, but Jan and Feb yes. I have sat and watched the boiler temperature Guage and it goes to 180 on most days. I know you don't believe me. But in my other thread when the l8124 was set a 165-170, we all froze in this house. So call it what you want but that's reality.


    Two different observations here: you're seeing 180 instantaneous. @JakeCK is saying <180 average temperature needed. Both can be true because of cycling.
  • JakeCK
    JakeCK Member Posts: 1,356
    TerrS said:

    The issue here is you are using today's standards with a 1950 design.
    So what? I have a 1920's house with a converted gravity hw system with cast iron that was originally heated by a coal fired boiler. And I could make a CI boiler, a Modcon, an electric boiler or even a a2w HP work with it.

    You're arguing with physics here.

    One question, if it's at design temp can the house stay at or above set point? If you answer yes, you do not need 180F water temp all the time even during January and February, let alone the rest of the season. If design for you is comparable to say northeast Ohio, at around 5f you could probably get away with water temperatures half that at 45f. And if you still tell me your house needs 180F when its warm out I only have one other question, are you a family of lizards?
  • JakeCK
    JakeCK Member Posts: 1,356
    To really visualize what were talking about here is a screenshot of my systems temperatures over a 24 hour period where temperatures were hovering right around 40f. To give it some context, the spikes you see is after the t-stat is satisfied and the circulator shuts off with the boiler. Realistically the supply temp never went above 120f, and if this was a modcon could be satisfied with 100-90f water.
  • WMno57
    WMno57 Member Posts: 1,250
    @pecmsg had it figured out back in September. The four partly closed ball valves. Probably also not full flow valves.
    I DIY.
  • TerrS
    TerrS Member Posts: 172
    @jakeck just out of curiosity, what kind of elements do you have in your house? Slant-fins or something else?
  • TerrS
    TerrS Member Posts: 172
    @WMno57 those ball values, 3 are completely open, only the one to the attic is maybe 1/4 of the way close. Given in-line is open and 90 degrees is totally closed. If I use a clock 9 and 12, it's sitting around 11. So that would not create this issue.

    I am still holding to I only have slant-fins and with only 104ft total and 30ft of that is in the attic. I have around 2100sq ft including the attic in my house.
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,823
    edited October 2022
    I am still holding to I only have slant-fins and with only 104ft total and 30ft of that is in the attic. I have around 2100sq ft including the attic in my house. 
    Slant fins still output at lower temperatures than 180, 180 is basically just a round number pulled out of a hat. It’s similar to “delta T should be 20” - doesn’t have to be. 

    Design temp be 160 or 200, just as long as it’s not boiling. 180ish needed at design temp and lower temps needed at higher outdoor temps is totally normal. 
  • TerrS
    TerrS Member Posts: 172
    edited October 2022
    @hot_rod and @JakeCK listen guys I am not trying to argue here and understand what you are saying and would completely agree if I didn't live here. So I don't know what they designed for. But I can tell you in the first 2 years I lived here we froze!!!

    The L8124 was only set to 165 and we froze, meaning the furnace ran all the time to keep even 68 degrees. I had a few friends in HVAC back in the early 90's and me having no clue, they asked me what my water temperature was. I had no clue what he was even talking about at that time. He told me how to set to 180 and all the issues went away at least for the first floor. The second floor has always been colder and Now 29 years later I am looking a new boiler and trying to solve the upstairs issues.

    So you are probably right days above 40 degrees could probably work at 160 degree water. But anything else doesn't keep this house warm.
  • Robert_25
    Robert_25 Member Posts: 527
    edited October 2022
    Baseboard output at different temperatures can be seen in the chart below. If you need 180 degree water with 30 degree outdoor temperatures, that makes me think something is not quite right. Something you can try that will only cost you some time is removing the baseboard covers and giving the fins a really good vacuum job. Even a little bit of dust will reduce the output. Something else to look at is how the system is balanced. If you have some parts of the house that are warmer than others, you may be able to balance that out using the valves you mentioned, and also with the dampers in the baseboard covers.



    Info from https://www.literature.mestek.com/dms/SlantFin/BaseLine%202000%20Brochure%20BL-10-2.pdf
  • JakeCK
    JakeCK Member Posts: 1,356
    I wouldn't call a radiator or emitter an element, I think of electric when I hear element. And a boiler is not a furnace. 

    That said I have cast iron radiators. And they are surprisedly well sized for the house. I too have an oversized boiler by a factor of 2. 
  • pedmec
    pedmec Member Posts: 959
    I think its already been stated you need more baseboard. Heat loss is not linear. The heat loss factor depends on a lot of things besides just temperature difference between the inside and outside. You have solar gains, wind, frost levels, infiltration, just to name a few. they all effect your heat loss. either way there are really only so many things to do. thermal imaging and insulating the heat loss. Try keeping the heat in. Best value for your dollar. then add baseboard and you can use reset control to lower your baseboard temps.
    TerrS
  • TerrS
    TerrS Member Posts: 172
    Slant fins still output at lower temperatures than 180, 180 is basically just a round number pulled out of a hat. It’s similar to “delta T should be 20” - doesn’t have to be. 

    Design temp be 160 or 200, just as long as it’s not boiling. 180ish needed at design temp and lower temps needed at higher outdoor temps is totally normal. 
    And remember this is why I installed the aquasmart last February. Prior to that the l8124 said give me 180 degree water and it always went there no matter what, well unless the house hit t-stat and turned off before.

    So this year will be a better test heating season. I just know from Feb to April, I saw many 180 water days, for the 2 weeks I was monitoring this, making sure it had a positive outcome. Or maybe i wanted to make sure I didn't make it worse.

  • TerrS
    TerrS Member Posts: 172
    @Robert_25 and @JakeCK my grandfather had cast iron radiators and his house was yes like the Bahamas. But we chalked it up to old age and thin blood and when I stayed there, we opened a window at night.

    He had 3-zones, basement/garage, first and 2nd floor and it was toasty.

    Back when I was 19, I had no clue but we did discuss it once and then I dropped it. Then 6 years later I bought a house with a boiler. Ohh how I wished I asked more questions back then..

    This is why I was asking the questions, I do remember he had at least 1.25" iron pipes, not my 3/4 copper.

    I already stated. But if I had all panel radiator like my 2 small buderus ones I have installed, they radiate heat like crazy compared to my fins. When My kick under cabinet blower turns on at 120 degrees water, the buderus is throwing off heat also.

    This is were I am at, spend $1000 for 4-71" 20" high buderus radiators, which are 8140 btus each, with is 3000btus over the fins, I completely agree I could drop my water temperature.

    But right now all my radiators are in series. And the buderus rads are using a bypass value as to keep flow moving down the line. So I would have a major plumbing reroutes, because the slant-fins are in one end and out the other, which I would have to bring both together to make them work for the way my house was plumbed.

    The only way I got the 2 I have now was I gutted my bathroom and kitchen and cut all the pipes. And redid everything to them. I don't have that option without another major construction project to reroute pipes in the rest of the house.
  • hot_rod
    hot_rod Member Posts: 22,024
    The fin tube output will be based on the average temperature flowing across them. So if you supply 180, return 160, use the 170 column for actual output

    When you have really long fin tube runs the temperature drop can be much higher, so the AWT would also be lower 

    When the system is running you could measure both ends and determine temperature drop and actual output. 

    Splitting the loop is sometimes done to shorten the fin tube length and increase output. Hotter fins, higher output

    We have seen carpet and pad added to homes that blocks some air flow across the fins and drops output

    Also systems where the fins were back  to front not up and down🥴

    when you measure, measure actual fin, not the enclosures 

    There here is  high output fin available also. For underperforming areas. Or for those looking to lower SWT to use mod cons or heat pumps better
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • WMno57
    WMno57 Member Posts: 1,250
    I suspect a water flow problem, possibly at the manifold or ball valves (are they full flow valves, if you post pictures we can tell). As @Robert_25 mentioned, it could also be an air flow problem.
    This should not be this difficult. You have a sensibly sized house with OK but not great insulation. Your boiler is about 75 - 80 percent efficient. 50 to 75 percent of the homes with older cast iron boilers have oversized boilers. Possibly you are slightly under radiated, let's come back to that.
    Lets try this from another angle. If you are raising your home's temperature from 60 to 72 on a cold day, how long would that take? How many times would your boiler cycle during that temperature rise? How long would each burner cycle be? How long would each pump cycle be? Maybe the aquastat needs more hysteresis; on at 150, off at 180.
    If the root cause of this is under radiation, pick a location on your first floor and install the largest cast iron radiator you can fit in there. 100 year old cast iron radiators are a dime a dozen because of the heat pump mania. And they are retro-fabulous! All the cool kids like @JakeCK and I have them. You deserve one too.
    You are not heating individual rooms, you are heating the envelope of conditioned space in your house. Most of the heat escaping through your boiler's jacket ends up on the first floor. I think if you set your programmable thermostat to 73 two hours before you get off work, you will be comfortable until you retire for the evening.
    I DIY.
    TerrS
  • TerrS
    TerrS Member Posts: 172
    @WMno57 so I can only provide a few answers. So at night for 2 reasons, we like to sleep cold around 64 degrees, you can always add blankets but if you are hot you can't get past your skin. Then during the day only 68 degrees. At 5am the thermostat says I need to be 68 now and the boiler lights. It takes 30 minutes to get the water from 65 degrees to 120  where my first sign of heat shows up. My kick starts blowing and my 3' buderus in the kitchen has hear. It then takes another 15-20 minutes to get to 180degree water and really warm the house. Boiler shuts off cycling the water until it has a 10 degree temperature drop. Now controlled with the built in heat manager in the aquasmart. Boiler fires for 10-15 minutes more, rinse and repeat for about 1.5 hrs to bring the house from 64 to 68 degrees.

    I would agree my house is just okay in insulation. Many updated rooms but even those were blown in and probably settled. So who know know. Btw. How does one tell where cold spots are in houses??

    I also need you please to define short cycle. Is 10-15 minutes short?  Meaning after that first 1.5hrs. Temperature raise doesn't take that long with a boiler that is still around 100 degree water. But this is where I think my other issues are. We are talking a 1990 boiler with probably little insulation so it loses heat fast. Go back to even I did my 1 week test of a hot 110 degree boiler. Required 5-6 fires per hour to just maintain that.

    Now when my boiler is at temperature it provides alot of heat. Meaning the more often it runs the quicker it  responds to demand.

    I will also agree that I lose heat, as my basement steps are in front of my boiler and there is a landing there, and its nice and warm there, so I tend to leave the basement door open to spill out.

    Would I like to keep my house at 70 during the day yes! But it takes almost 180 therms just to maintain 68. And because the thermostat is on the first floor in the dining room. My upstairs is even colder than 64. And we are now back to the beginning of this conversation???? How can I help this
  • JakeCK
    JakeCK Member Posts: 1,356
    Well going back to the beginning, improve the building envelope. Everything else becomes easier after that. 

    Do you have a basement? Walls insulated? Rim joists? Attic? Air sealing?
    Larry Weingarten
  • hot_rod
    hot_rod Member Posts: 22,024
    Something doesn’t add up here. The boiler is at least 2 times the output of the fin tube, from the info you provided 

    104’ of fin tube  @ 500 btu/ ft = 52,000 btu/ hr connected to it. So even from a cold start of 68 degrees in the boiler, it should reach a good return of 120 in 10 minutes or so

    What could be pulling the additional 50-60,000 btu/ hr?

    If you had all cast iron radiators and a lot of large steel pipe, maybe? But fin tube jumps up quickly.

    So basic thermodynamics would say, either the boiler is not adding near its output, or there is more radiation connected.

    Remember the heat emitters dictate the boilers operating condition, always
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    JakeCKScottSecor
  • JakeCK
    JakeCK Member Posts: 1,356
    edited October 2022
    She has mentioned a couple times about having other types of emitters including what I believe is a toekick and a couple panel radiators. I wonder if the different types are piped in such a way to cause her issues. 
  • TerrS
    TerrS Member Posts: 172
    @JakeCK and @hot_rod so when my thermostat turns on the boiler circulator also turns on. Which then starts that 10 gallons of water moving and heating. Again is why I brought up the new boiler has a 3 gallon smaller tank.

    Any how with the aquasmart I now delay the circulator by 2 minutes. Which has helped but it really needs to be like 7 minutes. I also run the circulator 3 minutes after the t-stat is satisfied and the boiler shuts off. As I was losing all that energy I just wasted but right after the water was hot, the thermostat said I'm done.

    I will tell you the 2 new rads and kick are only since 2017 and this problem existed well before that. At least the 2 rads and kick. Give off plenty of heat to my kitchen now, it's actually the warmest in the house.
    heathead
  • hot_rod
    hot_rod Member Posts: 22,024
    Suppose the boiler holds 20 gallons. To raise a gallon of water 1 degree takes 8.33 btu

    so somehow you must be getting some flow, maybe ghost flue if the circ is off and it takes 30 minutes to raise the boiler temperature 100 degrees?

    properly sized boilers can bring the fin tube up to temperature, circulating under load within that 10 minute time frame.

    Are you sure about the boiler output, if it is a 150,000 input, it must be running around 20% to make these numbers jive
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    ScottSecor
  • WMno57
    WMno57 Member Posts: 1,250
    @TerrS some good data there. Thank you. I need to think about all that. If your system could maintain 64 in the 2nd floor bedroom and 70 on the first floor would that be success? To maintain this differential within a single zone we under radiate the bedroom, and/or over radiate the first floor. The single thermostat could be in either the bedroom or first floor. A wireless thermostat would allow you to try both locations to see which one works better. Maybe you could take the thermostat to bed with you every night?
    Again, we are not heating individual rooms on different schedules. We are heating the entire conditioned space of the house. If heat first presents itself in the basement by leaking through the boiler jacket, then makes its way to the first floor, then makes its way to the second floor, that is not wasting heat. Heating your attic is wasting heat. If you want two separately thermostated zones that are on different schedules, that will cost far more in parts and labor than the additional fuel you might consume by only having one zone. You have a small house. One Zone. If we cannot agree on this then @hotrod and I will deliver Dangerous @EdTheHeaterMan to your home to drink all your beer. :D
    TerrS said:

    How does one tell where cold spots are in houses?

    From the inside; a thermometer. From the outside; a picture taken with an infrared or FLIR camera. This will show where the heat is escaping.
    TerrS said:

    My kick starts blowing and my 3' buderus in the kitchen

    @hotrod I think these emitters are in addition to the Fins.
    I DIY.
  • MikeAmann
    MikeAmann Member Posts: 996
    edited October 2022
    Just a thought - you said that you have a new SS flue liner.
    Was the draft checked and set afterwards? You said that you were partially blocked before the liner.
    If you have too much draft, then a lot of your heat could be going straight up the chimney.
    WMno57
  • JakeCK
    JakeCK Member Posts: 1,356
    edited October 2022
    WMno57 said:
    How does one tell where cold spots are in houses?
    From the inside; a thermometer. From the outside; a picture taken with an infrared or FLIR camera. This will show where the heat is escaping.
    With one of these bad boys. Flir camera for smartphones. I actually bought it used off a member of this forum.

    This is what has informed me on where to add insulation. Notice the foundation walls. The heat pouring out of the foundation was eye opening. 👀 This is what you need to do before replacing your boiler or doing anything else. Buttoning up the house may allow you to downsize equipment enough in a year or so to actually pay for the sealing and insulating of the house.





    MikeAmannWMno57
  • TerrS
    TerrS Member Posts: 172

    Lots of information here my head hurts as we are starting exceed my knowledge.

    So a few questions.
    1.  How do I find a person to do a house envelope scan? Because like the pictures you posted, if I can find the areas of badness, I can start fixing those 1 by 1, this would help overall everything.

    2. How and where can I buy/find a wireless thermostat or how does that work? Is it back to the boiler or connects to my current dining room thermostat?

    3. Chimney guy comes and installs SS liner. Boiler guy, cleans boiler, doesn't check anything about draft or how its combustion. Again I am at the mercy of them, and not knowing what questions to ask they go yep. Everything is wonderful and leave!

    In my previous thread and what @hot_rod gave me about heat loss etc, I had one HVAC, never call me back!! I blasted him with information he didn't want to deal with a smart woman home owner, it seems!! When I asked the other 2 to quantify the new boiler, they look like deer in headlights!  And go, trust me it will work. Umm dude! You are asking Me to spend $$$$ blindly. Ummm how about NO.

    Lastly, I have walked my house and calculated/measured all my fins, plus the 3' buderus and 2' in the bathroom and the new kick. And that 104ft is what I have.

    Also the piping question, the buderus have the bypass valves, so 35% into the rads, heat amazing and 65% onto the next rad. The kick has mono-flow tees as to force water into the kick. So everything seems to be plumbed okay.

    Lastly lol. Your right, why does it take so long to raise my water temp? I took the as the boiling the ocean effect. Meaning 6 gallons in the tank, plus all the water in the 4 zones circulating, so you continuously have cool water coming into that big pot.  eventually it all get hot, but it takes awhile. This is why I at least tried to help that setting the 2 minute circulator start.

  • TerrS
    TerrS Member Posts: 172
    Here are some pictures
  • JakeCK
    JakeCK Member Posts: 1,356
    there should be an energy audit program available in your area. Look into it. If you have natural gas talk to the gas co.

    The energy audit will often make use of a thermal camera if the weather permits. It is best to use them when there is a large delta T between outside and inside. Such as when its 10f outside and 70f inside.

    That is why I bought one of these: https://www.flir.com/browse/home-amp-outdoor/mobile-accessories/
  • Robert_25
    Robert_25 Member Posts: 527
    That circulator should be a 3 speed unit, what speed are you running it at?
  • WMno57
    WMno57 Member Posts: 1,250
    edited October 2022
    @TerrS I don't know what a good wireless thermostat would be. You might want to start a new thread in Heating Help's Thermostats and Controls category.
    https://forum.heatinghelp.com/categories/Thermostats_and_Controls
    I DIY.
  • neilc
    neilc Member Posts: 2,691
    imma tip toe on a limb,

    it's the fireplace,
    stand in the door to the fireplace room, with your back to the roaring fire, feel that breeze on your face?(dampen your face)
    go stand in a pinch point at the stairwell, looking up, feel a breeze on your face?
    turn on the clothes dryer, kitchen exhaust fan, and bathroom fan, go to an exterior wall, barefoot, breeze at your feet? (hardwood or carpet, )
    put the back of your hand to an outlet, or light switch, exterior, or interior wall, feel that breeze?
    any can lights or ceiling lights or fans, on top floor, or anywhere for that matter, back of your hand, breeze?

    I didn't insulate near as much as I air sealed, I'm much more comfortable.
    known to beat dead horses
    MikeAmann
  • TerrS
    TerrS Member Posts: 172
    And here is the problem with insulating too well at the moment when you are doing major renovations and feeding wire thru walls. So insulate the major, understanding the minors and be happy 😊
  • neilc
    neilc Member Posts: 2,691
    did I miss where you're renovating?
    perfect opportunity while walls are open to seal any holes, pipe chases, duct chases, or any at all,
    in the top and bottom plates, or exterior walls,
    known to beat dead horses