Does having multiple zones in large house in Western Massachusetts save money?
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I have to ask, is this boiler a cast iron boiler? Is the boiler leaking??? Is there any reason you cannot continue to use it with improvements like a new burner and dual low water cut offs to comply with plumbing code?
Fixing and improving the envelope of the home will provide immediate benefits if home energy funds are available.
The radiators need work and may need new valves/repacked valves. Do you have an attic? Is there an open to air expansion tank in the attic?
Does the system have a steel compression tank in the basement? If it does have a steel compression tank do not let them remove it, you can keep the compression tank to maintain the point of no pressure change.
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Thanks for this LRCCBJ! You are right, most of the radiator values have not been touched. Most of them are impossible to turn. But I like your idea of trying to just balance the house by adjusting the values. It would probably be significantly cheaper to replace the values then break the house into zones.
If we break the house into zones, we would install the manifolds in the basement and run Pex from the manifold to the where the radiator pipes attach to the supply and return pipes in the basement. We would not run pipes all the way up to the radiators, through the walls.
My thought was that if we got rid of the very big supply pipes in the base, there'd be much less water to heat and that would contribute to saving money, along with improving comfort, have better balance in the house, and being able to keep less used parts of the house cooler.
Is there a way break up the house into zones via thermostatic radiator valves? Is there away to install these valves and have them be controlled from a different location then the room? I just googled remote controlled thermostatic radiator valves and this came up:
WiFi Smart Thermostatic Radiator Valve Anti-scale Mode Rotatable Screen Digital Heating TRV
Are systems like this any good?
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You're welcome, @SecondEmpireHouse .
From an energy efficiency standpoint, the greatest savings come from thermal purge when systems can heat up, anticipate the end of the thermostat call, turn off the burner, and then purge the heat remaining in the boiler and piping out to the radiation. The best way to make that happen is by zoning comfort areas. With large cast iron radiators, we always recommend primary/secondary piping to ensure adequate flow to more evenly heat the radiators; this also works very well with thermal purge.
In your case, you mention that the first floor heats to a comfortable temperature and the upstairs effectively is overheated during that thermostat first floor call. Having that single thermostat on the first floor to control your entire 6,200 home is why you're considering zoning in the first place. I think your comfort could improve with thermostatic radiator valves on those floors, but be aware that the only time those radiators will heat is when the thermostat call is on for the first floor. Since you have excess heat on the other floors (I presume from the radiators heating them), I think this could improve/reduce the temperature in those rooms once properly adjusted (which means the TRVs are all working with you likely owning the adjustments over time vs a contractor returning frequently to tweak settings). It will not be an optimal solution like separately zoned comfort areas, but it will likely cost less as well. Another consideration: Sometimes thermostatic radiator valve systems have constant circulation, which will maintain temperature in the system and the boiler, which is much less efficient than thermal purge as it increases idle losses.
Best,
Roger
President
Energy Kinetics, Inc.1 -
The boiler is a Weil McLain which I believe is cast iron. I've been told it was made in 1991. It actually heats the house very very well and I have it cleaned every year by experienced technicians. It's 34 years old and I'm sure it will last a lot longer. But I don't want to have to worry about having a problem and having to do an emergency replacement. And I think a new EK2 which has been recommended would give me great piece of mind and hopefully will consume less oil. Mass Save has audited the house and added insulation to walls and attic and sealed the house the best they can. There are a few more things I will do to improve the envelope of the house but getting a new boiler is part of the upgrade I'd like to do.
There is a steal Expansion Tank in the basement. Is that the same thing as a compression tank? The attic does not have anything associated with the heating system as far as I know. Because the top roof is pretty flat, there is not much space between the floor of the attic and the roof, and that space is totally filled with insulation.
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my thought might be to repipe basement piping to clean it up and then split off main floor from rest of common piping feeding 2nd and third. This would give a chance to now have 2 pumped zones. Neaten up radiator piping on main floor, hacked up (currently). Maybe do TRVs on 3rd floor with 2nd floor having thermostat. I think this might be the most bang for buck for comfort and efficiency. My .03 worth.
Good luck1 -
Thanks for this Roger… So to be clear, if I install thermostatic radiator valves that are not connected to the boiler and have the ability to call for heat, then I don't have to worry about losing the thermal purge feature your systems has, right?
Besides improving comfort, will having thermostatic radiator valves on at least 4 radiators that always over heat their rooms (three on the 3rd floor and one one the 2nd floor) result in less oil consumption? Will my operating costs decline?
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@SecondEmpireHouse , as an alternate to zoning, I was suggesting that you might consider installing primary secondary piping to heat your entire house, and have that controlled by the thermostat on the first floor. Water would still flow through all your radiators whenever that thermostat called; the TRVs would restrict flow in the overheating radiators, but those radiators would only heat when the first floor heating was active.
If the TRVs independently call the boiler (instead of just restricting flow to those specific radiators), and you only have one zone, then the entire house would heat whenever those TRVs were calling (or when the first floor thermostat was calling) because you have no way of restricting flow through the entire house aside from TRV set points.
The thermostat on your first floor would signal the boiler when heat is required for your house overall. The TRVs would simply restrict the rate of heat flowing out of certain radiators where they were set to do so.
Best,
Roger
President
Energy Kinetics, Inc.1 -
If the existing boiler is in decent shape, I think you can stop this buying process. There can still be merit to adjusting the piping.
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If the cylindrical steel tank is hung between the floor joists above the boiler it is a steel compression tank.
Please post a picture of the plumbing above the boiler and around the boiler.
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You can get the valves to function if you are patient. Spray Kroil or PB onto the stem every day and let it soak into the stem. You can also relieve the pressure on the stem by cracking the packing nut loose.
You mention that you would run Pex to the points in the basement where the supply and return pipes appear. The important question is what do the supply and return pipes feed? Do you have one set of supply and return pipes for each floor? I tend to doubt this is the situation. If truly the situation, the logic of zoning in the basement makes perfect sense. Running pex to the three supplies and three returns is not a massive endeavor.
You are correct that elimination of the huge volume of water in the 2" pipes would improve the efficiency of the system. Right now, every time the boiler starts you must warm an estimated 100 gallons of water before you get any heat to the rooms. When the water in the basement pipes cool down, all that energy is wasted to the basement and you get nothing from it.
You can break up the house into "zones" using thermostatic radiator valves. Each radiator is its own zone in this configuration.
I believe you'd prefer a less costly and simpler solution than the one you provided:
https://www.supplyhouse.com/Danfoss-013G8020-3-4-Straight-Thermostatic-Radiator-Valve
These are manual valves and are controlled from the dial on the valve. For comfort, that's all you need. The electronic valves are considerably more costly but available if you must have them.
You could install these on the third floor for sure and fix that issue immediately. I'd see if I could get those existing valves on the second floor to work and utilize them for periods where the second floor is unoccupied.
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The old boiler is a model 68 which is old . It may be older than you think.
I seem to recall installing the Weil McLain Gold in the mid 80s with the Gold Jacket.
I could be wrong but I am sure others will comment.
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One good thing that can be said about your boiler is that it appears to be the right size for your heat loss, which we don't see very often. Usually the boiler gets oversized because the installer uses an overly conservative "rule of thumb" sizing method.
Based on your oil consumption, and subtracting some for your domestic hot water, it looks like your heat loss on a design day is around 20 BTU/hr/sq ft, which is good for an old house in your area. So 20 BTU/hr/sq ft x 6200 sq ft x 1.4 ASHRAE recommended sizing factor = 174,000 BTU/hr, which is right at your boiler's DOE rating.
We are used to seeing boilers 2x or 3x oversized, so it's good to see an exception to the rule.
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@LRCCBJ : "You are correct that elimination of the huge volume of water in the 2" pipes would improve the efficiency of the system. Right now, every time the boiler starts you must warm an estimated 100 gallons of water before you get any heat to the rooms. When the water in the basement pipes cool down, all that energy is wasted to the basement and you get nothing from it."
Maybe, maybe not. Going back to my earlier post, the point of a heating system is to provide comfort. The heat in those pipes isn't lost, it goes into the basement. Now, if it doesn't contribute to the comfort of the house, yes, it's wasted. But if it does contribute to the comfort — if, for instance, the first floor would be colder without it — then it's not wasted. Whether or not it contributes is determined by the construction of the house; houses are like snowflakes, every one is different.
Same deal with "purging." Whether or not it's useful depends upon what would otherwise happen to that heat.
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Got it thanks… I'll have to look more carefully if the house and primary and secondary piping or not.
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It is completely wasted, despite the ongoing claims of otherwise. It adds maybe 2 degrees to the basement, if that. Just forget about every BTU put into that piping. You're not getting any of it as a return.
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Do not bother with primary/secondary piping with a CI (or a steel……..EK) boiler. The boiler can easily accept the flow rate from the system without any issue.
P/S piping is only used when the boiler needs a greater flow rate than the system can provide. With Cast iron, the opposite is the issue…………..the need to control the flow to the boiler to prevent condensation when the return water (that giant 100 gallons) is too cold. This is accomplished without primary/secondary and the boiler needs a bypass (ESBE valve).
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Thanks for this @LRCCBJ … there are definitely large supply pipes and smaller return pipes in the basement that all the radiators through out the house connect to as far as I can tell. My plan had been to eliminate the large supply pipes which had been for steam, and eliminate the smaller return pipes in the basement too… pex was to be attached to every supply and return pipe that connected directly to a radiator. All this work was to be done in the basement.
So there would be less water to heat up, along with the benefits of zoning the house. But this is a big expensive job and costs about the same as installing an EK2 boiler and 330 gallon oil tank.
The general sense I'm getting from the experts on this posting, is that repiping the basement and breaking up the house into zones would result in the most comfort, and even heating, and be the most efficient way to heat the house. But the pay back in savings from this repiping could be decades away. A good alternative would be to install thermostatic values in the rooms that over heat, and leave the big pipes in the basement alone.
After the new EK2 is installed, with in a few years I'll know how much I'm saving in heating costs. I'll know if the projected savings materializes or not. If they don't the next step could to break up the house into zones which I could do in a few years.
There is a house down the street from me that is a little bit smaller than mine but in the same style as mine (built in the late 1800s, big rooms, high ceilings, lots of original windows, storm windows, and well insulated) that recently got an EK2 boiler for hot water. And this house has the same kind of large steam pipes in the basement as I do.
But they consume about the same amount of oil as I do, around 2000 gallons of oil a season. So I really look forward to seeing if the EK2 will make it less expensive to heat my house.
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@SecondEmpireHouse , I'd like to clarify that adding primary/secondary piping is the only way to go with cast iron radiation and Energy Kinetics boilers. The boiler monitors the return temperature and turns off the zone output when the return temperature would cause condensing; the burner remains on, just the zone output closes. This cycling can cause heat to be pulsed out and result in uneven heat as the first radiators would heat faster than downstream radiators. Cast iron boilers frequently cycle the heating circulator in the similar conditions, so primary/secondary piping is a good design practice in large water volume systems. After installing primary/secondary piping on cast iron radiator heating systems, we frequently hear that the house has never been more comfortable as the heating of the rooms is much more even. Your home is 3 floors and imbalanced as it is, I'm sure it needs more than just primary/secondary piping to balance the heat. An additional comfort advantage could be attributed to the removal of the draft regulator (which increases infiltration air and can make the home more drafty and less comfortable as well).
Roger
President
Energy Kinetics, Inc.0 -
Thanks for this Roger… but when you look at the pictures of the large supply pipes in the basement and how smaller pipes connect the radiators to those large pipes in the basement, and then you see that the all the radiators return pipes connect to one pipe that basically runs along the exterior walls of the basement… doesn't that constitute a primary and secondary system?
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Thank you, @SecondEmpireHouse .
A primary/secondary system will have a dedicated circulator on the primary loop (the water will continuously circulate whenever there is a heat call and during thermal purge). The boiler will “inject” heat into the primary loop. It’s not typically a major change, but the difference in functionality is not trivial.
Roger
President
Energy Kinetics, Inc.1 -
This is by no means a scientific study with accurate measurements of the before and after fuel usage. This is just what happened and how I stopped a fuel oil customer from changing the boiler to gas heat. Of course the oil dealer had mixed emotions because the house went from over 3000 gallons per year to under 2000 gallons per year.
SecondEmpireHouse Said: “If I put thermostatic radiator valves on radiators in the bedrooms, we could control those rooms from getting too hot and make the rooms more comfortable. I wonder if that would save on heating costs?
What if we had thermostatic radiator valves on all 22 radiators in the house? What would be the effect of that on heating costs and comfort?”
Betty L was an older customer of the oil dealer that I used to do service calls for. She wanted to save on her fuel bill in the large home that was broken up into several rooms that were rented out to members of the US Coast Guard stationed in Cape May NJ. There were other renters and some of them were unhappy with overheating radiators in their particular rooms. One renteer happened to live in the only multi room apartment with a full kitchen on the first floor. That was the coldest zone in the building because the renovation included cast iron baseboard for that apartment while all the old gravity heat radiators and large piping were feeding the rest of the rooms.
Betty L wanted me to install new manual radiator valves so she could turn off radiators that were in rooms that were too hot. She has selected 8 radiators out of the 20 radiators in the home to have the valves replaced. After a lot of persuasion, I was able to get her to agree that a thermostatic radiator valve would do what she wanted automatically and no one needed to touch the valves once they were set to the comfortable temperature for that room.
To add to the confusion, on the day I was set to install the valves, she asked me to just put in the lower cost manual valves (that I did not have with me) and I told her that is not the way I do business and said thatI would rather give her money back so she would never call me again. That was not to her liking because I did the oil burner maintenance for the previous 4 years and she never had trouble in the winter unlike the previous service companies So she said to put the 8 automatic TRVs in as agreed .
That winter the fuel usage went from over 3000 gallons to under 2000 gallons. That is because the rooms were no longer overheating and the tenants were not opening the windows in the middle of the winter to get some relief.
So to answer your query about savings using TRVs. You will have some savings. Will it save you as much as Mrs. L? I can't say That depends on how much overheating you are experiencing, and if you open windows in the winter to compensate. All I know is that Betty did not convert to gas heat but the oil dealer was unhappy with the loss of 1000+ gallons that he expected from that customer. But agreed that it was better than losing all those gallons to the gas company.
The next summer Betty purchased 11 more TRVs and moved the sensor to the thermostat to that cold apartment that had the CI baseboard. The cold apartment didn’t have any TRVs so that would allow for constant circulation that I designed using a ∆P circulator and the outdoor reset I included in the price of the 11 new TRVs. The following winter the fuel usage was down to about 1600 gallons.
I though that was enough savings for that customer. I didn't want the fuel dealer to loose too much or we might not be friends anymore.
After 25 years, we are still friends.
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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Thanks a lot for this EdTheHeaterMan! The story you told is very very interesting! Much appreciated!
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Thanks for this Roger! We do have a circulator on the primary loop! All the best… dan
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For my money I would put primary secondary on every job. Especially when zoning. Without primary secondary you shut some zones you are restricting the flow through the boiler. With primary secondary the boiler Always has the correct flow. Just makes sense to me as it keeps the HX happy.
and it usually solves return temp protection if the flow rates are right although a sensor on the return is the only correct way
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This is very interesting to me, I was always under the impression that multiple zones was always best.
My house has one huge loop for upstairs and downstairs, so one zone. I keep it that way so the boiler cycles longer and less often. The thermostat is in the downstairs in the most commonly occupied area, I have balancing valves for upstairs and downstairs, I just adjust the upstairs valve and it works very well
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@RascalOrnery , I believe the primary savings identified in @EdTheHeaterMan 's post are correctly identified in his analysis; "That is because the rooms were no longer overheating and the tenants were not opening the windows in the middle of the winter to get some relief." There will be energy savings from being able to keep the rooms cooler (unrelated to open windows), but that will be a much smaller figure than from closing the windows.
Your balancing valve adjustments are a good solution for your home and it works well for you. Overall, I believe that having a reasonable number of zones for discrete comfort areas (bedrooms together, primary living spaces, master bedroom and bath, etc) is always desirable as each can be controlled and kept at different temperatures. Combined with a low mass/thermal purge boiler, the boiler purges and finishes cold, so energy is not wasted after each thermostat call, delivering high efficiency for large zones, small zones, and hot water. Hydronic micro-zoning can be over done (every room as its own zone for example) as this can cause frequent thermostat calls which can keep the boiler hot much more of the time; this increases idle losses and can lower efficiency.
Roger
President
Energy Kinetics, Inc.
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