Does having multiple zones in large house in Western Massachusetts save money?
We are about to sign a contract to replace our 30 year old boiler with an Energy Kinetics Frontier for our large house in Western Massachusetts. The question is do we also convert the house from one zone to four or five zones? Would doing this save money on heating?
The house was built in 1881, is 6,200 square feet, and has three floors. The bedrooms on the 3rd floor and 1st floor are always occupied. The bedrooms on the 2nd floor are occasionally occupied. The third floor is usually 10 degrees hotter during the heating season. The thermostat is on the first floor. The supply pipes in the basement that feed the radiators are very large because the system used to be steam but was converted to hot water. I consume around 1,500 to 2,000 gallons of oil a season.
If we convert to 4 or 5 zones, we’d remove all the big supply steam pipes in the basement and replace them with PEX, along with replacing the return pipes in basement with Pex.
Of course having zones will enable us to have even heating though out the house, and even allow us to keep some zones a little bit cooler too, if desired. I suspect replacing the large steam pipes with Pex will result in less water to heat up and will contribute to saving money. And that having zones will also save money.
What do you all think?
Comments
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Define saving money here - nothing about this will save money I suspect vs the investment of the new boiler.
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so
Your getting rid of Steam and changing to HW?
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Hi pecmsg… The house currently is hot water… once upon a time it was steam…
And thanks for your comment Hot_water_fan… I'm not sure what you are saying…
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I don't know if the contractor gave you a price for the boiler replacement and a separate price for repiping but I would just look at the repiping cost versus comfort. The EK will save you money on fuel weather you repipe or not, but you should save more with zoning.
6,200 square feet is a lot of house so I would think zoning is worthwhile but that also depends on the repiping cost.
Hopefully you have a good contractor that knows what he is doing. We have a few good contractors in Western, Ma. Did you get more that one quote? What city are you in?
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The lower the temperature in any of the rooms, the less the heat loss, hense the less energy needed. Individually controlling the 3 floors could also add to the comfort level. Lower temperature in the unused or seldom used rooms.
If you can reuse the radiators, individual TRV could be added for even more room by room control.
Since it has already been converted from a steam system?
The cost of that conversion may not payback, if that is a concern.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
You said
"The supply pipes in the basement that feed the radiators are very large because the system used to be steam but was converted to hot water. I consume around 1,500 to 2,000 gallons of oil a season."
So it sounds like the entire house has already been converted to hot water, and your only question now is whether (a) zoning and (b) replacing the big old pipes with PEX will save money?
I am dubious that zoning is going to save you enough to pay for the repiping.
And you can gain better control of the temperature throughout the house by partially closing the radiator valves in the hotter rooms. You can also install a smart thermostat like an ecobee with wireless remote sensors. The thermostat can go on the first floor, with the sensors on the other floors. The thermostat will average the sensed temperatures and use that average as a control input, vs. just one input from a first-floor thermostat.
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I am saying do not expect replacing a boiler with a new boiler to save you money. Ditto with repiping.
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Is your boiler leaking?
Pictures of your entire system would help. Are you sure it was heated with steam before this? I question that because the steam radiators would not work with hot water heating.
Replacing all your pipe with pex will eliminate a great deal of thermal mass that is already in the existing pipe and your system will have less water in it-hence less useable heat.
I would ask another contractor for a quote for simply replacing the existing boiler with one made with cast iron and adding 2 low water cut offs and any needed plumbing.
A single zone will manage the heating system more effectively.
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EK has a bit different opinion on the fuel savings by just replacing a 30 year old boiler with one of theirs. Up to 40%?
Maybe they will weigh in with some independent lab tests and results?
A more efficient boiler should reduce fuel consumption, all things being equal. And if the old one was oversized or grossly oversized, it could be running 60% or less cycle efficiency.
Since you have a record of oil used, I guess you will find out. :)
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
Something doesn't add up quite right here. If indeed the system was once steam — which may or may not be the case — it may be that the conversion to hot water was not done all that well. Paritcularly one wonders if the radiators were properly converted at that time.
On the other hand, if it was once gravity hot water — which is quite possible — the existing piping may actually not be too bad for hot water heat, provided it's done properly — which, if it was not, might account for a good bit of the uneven heating.
In either case, neither replacing the boiler nor zoning will save you money, or at least not enough to pay for the job.
Is it possible to insulate the house better? Are there storm windows throughout? Those things will save money, and are a better investment.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
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I think the “up to” does a lot of work there :)
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I suspect your system was originally gravity hot water rather than steam, which would account for the larger pipes. If you show us a photo of a typical radiator, including both ends, we can tell you.
None of the proposed work will save enough money to repay its cost in a reasonable period of time. You have an older boiler though and it may be time for something new; the EK is an excellent choice.
You might consider non-electric thermostatic radiator valves of the type used throughout Europe to reduce the upper story overheating and allow you to keep unused rooms cooler until they are needed. The system could continue as a single zone with no repiping needed except to fit the new valves on the second and third floors only and perhaps to install a modern ECM circulator that will respond to the demand for heating by varying the flow rate. This may also require primary/secondary pumping with the boiler on its own circulator.
Outdoor reset control would also be a wise investment in comfort and fuel savings.There are some excellent hydronic heating contractors in Western Mass.: Charles Garrity in Springfield and Wilson Services in Northampton. Both are listed in the "find a contractor" feature of this site. You might ask them for their opinions.
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Bburd0 -
To be clear, replacing with an EK isn’t a bad idea necessarily. But if “saving money” is the goal, I’d be skeptical. But if adding headroom, improving comfort, etc. is the goal then repiping could make sense.
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and the higher the transfer between rooms.
There’s not a significant savings.
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Agree with others that its quite possible your system was gravity hot water from the start, not steam.
I had one heating pro who saw the large diameter pipes in our basement and told me (incorrectly) that our 1924 Boston-area house was originally steam.
It was not, because none of our radiators have the bosses drilled and tapped where the air vents would have gone, and there aren't any ports on the pipes in the basement where main vents would have gone.
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If the OP is replacing a 30 year old boiler why not do it? The more square feet you have the more likely you will get some savings.
Sounds like the OP could use a Mod Con but maybe he doesn't have gas in his area or want propane.
Zoning a three story when the second floor is not used is a no brainer for me save some energy if you can. But there is likely no insulation between floors so savings will be minimal.
Like I said it's about comfort and there will be fuel savings and the 30 year old boiler may not last much longer
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Here are some of the very large supply pipes in the basement and some of the radiators in the house.
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And here are some close up of values and more radiators…
So does this say to you this was once upon a time a steam system?
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Does having multiple zones in large house in Western Massachusetts save money?
Definitely in eastern Massachusetts…. But it might work in Western Mass also.
I believe that properly zoning your home will save a significant amount of money for several reasons
- You said: "The bedrooms on the 3rd floor and 1st floor are always occupied. The bedrooms on the 2nd floor are occasionally occupied." By setting the thermostat in that unoccupied area to a lower setting by 10° those rooms will not lose as much heat thru the exterior walls, floors and ceilings. There will be some heat loss from the surrounding rooms into the unheated or lower heated rooms, but that cooler space will act as insulation between the heated areas and the unheated or lower heated rooms.
- You said: "The third floor is usually 10 degrees hotter during the heating season." This means that those third floor rooms are losing more heat as a result of over heating them. By controlling those rooms to a lower temperature, the difference between the cold wall outside to inside temperature difference will be lower. That temperature difference is the definition of a load calculation. No one on this site will disagree that the same home built in Upstate Maine and in the middle of Virginia have completely different ∆T making the Virginia home with the lower ∆T have a lower fuel cost. So those third floor rooms with the lower indoor temperature as a result of zoning will use less fuel than if you left things as is with one zone.
- You Said : "The supply pipes in the basement that feed the radiators are very large." That large pipe with a large water volume will use more fuel to heat it up, so the response time from the call for heat to the thermostat being satisfied will be longer, but there is a savings on the back end where that same water will take longer to cool off. With the EK thermal purge feature that savings will be very little, but there will be some savings.
- There are studies that show that proper zoning can actually lower the fuel needed to keep the home comfortable, for example: you may not need to send hot water to a zone that has a substantial solar gain while rooms on the north side of the home require heat. That way no heat is wasted being sent to rooms that do not need heat.
I believe there are other reasons that zoning is a good idea. Comfort is worth something. If you could put a number on that, then you can add that to the savings. Would you pay $1.00 per day to be more comfortable? Then there is $100.00 value to add to the savings for all the years that EK boiler is heating your home with the properly zoned system. Just be careful that you don't create MicroZones that will wreak havoc with your system.
North side/South side. May be a good strategy if you are thinking about more than just first floor, second floor, third floor.
Also, those photos of some of the radiators look like an old "Paul System". That was a Steam System with two pipes and no traps. The supply was one size larger than the return. That would have been an easy system to convert from Steam to Hot Water years ago. @SecondEmpireHouse may be correct about it being a steam system at one time.
Either a Gravity Hot Water or a Steam system with big pipes can often make for unusable basement space as a result of the need to properly pitch the piping to allow for the condensate or gravity water flow. Removing those head knockers to gain additional space has another value that needs to have a dollar value placed on it. The real estate market can tell us what those extra rooms might be worth at resale time.
I would zone it if it were my place.
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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Confusing radiators.
Some look like they were two pipe air vent steam system.
Others look like HW
Either way two pipe air vent steam sucks so be glad it's gone if you had that.
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Thanks for this EdTheHeaterMan… There are a number of reasons to break the house up into zones but it costs a lot. Getting rid of the old pipes and installing new Pex in the basement and all the other associated equipment will cost more than the cost of the EK2 boiler and new oil tank. Is there a way to calculate how much more I'd save with the zones which would be on top of the savings I'd get with the new boiler?
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Thanks for this EBEBRATT… yes I have quotes from 2 contractors that have given me a breakdown for the costs of a new boiler, and the cost of breaking the house up into zones. I am waiting for a detailed breakdown from one more contractor.
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Thanks for this Hot-rod… TRV are good idea for me to explore. I will talk to the contractors who are providing bids. If I don't break up the house into zones, adding these valves on the 3rd floor might be a very good idea… assuming they will work for the kind of radiators we have…
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Thanks for this Jesmed1. What would be the benefit of having a thermostat on the first floor with sensors around the house? If the first floor is at a comfortable temperature, say 68 degrees, the third floor will be in the mid to high 70s.
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Yes you are right there is no insulation between the floors. There is good insulation on the exterior walls but not on interior walls or floors. It's not possible to heat the house with natural gas since the gas company is not taking on new customers. I don't want to switch to propane.
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Looks like a lot of those radiators were replaced at some point. Maybe they froze and burst?
Some of those radiators have two shutoff valves. Are the supply and return connections the same pipe size?
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting0 -
At days end only you can decide if the juice is worth the squeeze on any of the proposed changes. 2000 gallons of oil at ?? how much per gallon?
Would a 20% reduction be worth it? Maybe, maybe not.
If the boiler is having issues, I'm confident a newer more efficient boiler will save $$.
You best option for saving heating dollars might be building upgrades. Have a blower door test and infrared scan done to see where she is leaking $$s.
From the on-going leak potential alone, I would repipe with pex. Not to mention the ugly piping, and flooring butchery done over the years :)
TRVs in some or all areas.
A home run to a couple manifold locations, maybe one per floor is anoyther option. Zoning could be done manifold by manifold, or even loop by loop with actuators.
A couple piping examples, these show fin tube and panel rads, same concept applies to CI rads. No mixing stations required in your case either.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
Taking a step back - why replace the existing boiler? Is something “wrong”? What? Repiping could be a more effective choice here.
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The supply pipes are for the most part larger than the return pipes. WE have have never had a radiator freeze or burst since the house has been in my family since the late 1960s. I'm not sure about the history of when the radiators were installed.
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The house walls are well insulated although I will insulate the rim joists in the basement this summer. I'm also going to get an estimate for spraying a layer of closed cell foam on the basement. The other upgrade I can do to the house is replace the storm windows with QUANTAPANEL storm windows.
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Those radiators are all older than the late 1960s, but some are older than others.
The one with a slightly rounded top is a column type, last made around 1925.
The flat-topped ones where the spacing of the sections is 2-1/2" were in production from about 1925-1938 or so. These are called "large-tube" radiators.
The flat-tops with lesser spacing went into production around 1938, and some of them are still being made. They are known as "small-tube" or "thin-tube" rads.
That, and the fact that some of the rads are not nearly as long as the space between the risers (through the floor) that feed them, tells me they were replaced at some point.
The pics of the basement piping only show one set, and I'll bet they are the supply pipes. Can you show the pipes going from the rads back to the boiler?
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting0 -
The smart thermostat with remote sensors is only one-half of the two-part strategy I mentioned for better temperature control. The other half of the strategy is partially closing valves on radiators that are getting too much heat (or adding TRV's as others have suggested).
So valving down some radiators on the third floor will reduce the temperature spread throughout the house, and the remote sensors will help the thermostat keep the entire house closer to the desired average setpoint.
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The whole point of heating is comfort. If you can get the same comfort level with less heat, you save money.
Heat moves readily within the house so not heating part of the interior has less of an impact than you might think. The way to think of it is in terms of average interior temperature of the whole house. Based on the description I think you could reduce the average interior temperature by about five degrees with zoning with no loss of comfort.
I would estimate your average outdoor temperature during heating season is about 35F, for a temperature delta of 35F. Reducing the average indoor temperature by 5F saves one seventh of the fuel, or 14%. Let's say that's 200 gallons a year, or about $700 at today's prices.
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Great discussions, everyone!
First and foremost, I will reiterate that upgrading 30 a-year-old boiler to an Energy Kinetics system will cut fuel use. Excellent independent studies that support this conclusion are referenced in this page that links to a report from the Department of Energy that evaluates system types and designs, and this broad based report from NORA that analyzes before and after fuel consumption normalized with local heating degree day data. The NORA report was recently completed and shows the average savings from upgrading older equipment to Energy Kinetics design to be 25%; savings of over 40% was also documented.
We recommend zoning comfort areas. This typically means zoning bedrooms together, maybe a master bedroom/bathroom on its own, and then zoning other (groups of) living spaces together. Micro zoning is expensive and inefficient because at least one zone is often calling throughout much of the winter which keeps the system in standby and wastes energy. Zoning comfort areas combines comfort (obviously) and efficiency. Unfortunately, I don’t have studies like on boiler upgrades to identify the savings that are possible.@SecondEmpireHouse , my suggestion would be to consider breaking your house up into zones for comfort reasons with the understanding that you’ll get some savings along with the comfort benefits. For a smaller budget, maybe you can break up the first floor as its own zone as that sounds like it’s your primary living space; maybe there are other logical ways to break out comfort areas that make sense for you and your home for a budget you feel is more acceptable.
I like your plan to improve your building envelope with retrofit storm windows (although I don't have experience with QUANTAPANEL) and weatherizing to address "low hanging fruit" - basement rim joists, knee walls in attics, high hat lights, etc. are typically cost effective targets.
Best,
Roger
President
Energy Kinetics, Inc.2 -
Thanks Steamhead… you really know your radiators…. I wonder how the house was heated before the radiators were installed… here are some pictures taken in the basement where you can see the cooper return pipes. In 2019 we replaced some of the return pipes in the basement with copper. In the last photo the pipes have not been replaced by my family and came with the house. As you can see the supply pipes, at least when they run horizontally in the basement are pretty big. So can you say for sure the house was once heated by steam? Is it worthwhile replacing the big pipes in basement at great cost if the main objective is to lower one's heating costs? I'm beginning to think there are better ways to spend that money, like spraying close cell insulation…. what do think?
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Well that is very very interesting… I will look in to this option! Thanks so much!
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wow… thank you very much for doing the math on this… this is very helpful!
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The question is do we also convert the house from one zone to four or five zones? Would doing this save money on heating?
The answer to this question requires more information. This is the reason you are getting opinions that are all over the map.
If the contractor is going to need to run piping up through the walls to the second and third floors to achieve three independent zones, by floor, the cost is going to be prohibitive, and there might be added damage and repair to walls on the first and second floors to enable the piping to reach the third floor directly.
I had a house, two floors plus an attic, where all the piping for the radiators from the second floor went straight to the basement. I set it up with 9 zones with zone valves in the basement. Not difficult or costly to do. But I doubt a three story has that benefit and the cost is ridiculous (as you noted).
It is noted from your photos that none of the radiator valves have been touched in years. The most economical solution is to get those valves to turn and USE THEM to balance the house. Close the valves down on the third floor until the third floor reaches 70F. This will take a bit of iteration on your part as you don't know how much to close the valve. Close the valves on the SECOND FLOOR ALL THE WAY CLOSED. As you stated, you rarely need heat on the second floor and the second floor will never get below 60F due to the upward flow from the 70F first floor. If you expect guests on the second floor, you simply open those valves before they arrive.
If I were doing it, I would simply close all the second floor valves. DONE. Now see what happens to the third floor. It might be quite comfortable due to the loss of the heat that is not entering from the second floor. In fact, the third floor will now send energy DOWN to the colder second floor.
The above can achieve your comfort goal at minimal cost and will certainly offer some fuel savings. Currently, there is significant loss to the attic (presumably unheated) and some loss to the second floor with a 77F third floor.
If you go with the contractors cost, you'll never see a return in your lifetime based upon fuel savings.
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Yup- that was originally a steam system. The giveaway is in the second pic- note how the pipe elbows down and is capped. That was for a "drip" connection to the wet return, which disposed of condensate in the main and sent it back to the boiler.
Given everything I've seen in this thread, it looks like this system has been well and truly kludged over the years.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting1 -
Thanks for this Roger! Good to have you weighing in like this. I suspect that any breaking up of the house into zones is going to cost a lot… it will cost as much as installing one of your boilers and new oil tank.
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?
If we had one Thermostat in the dining room on the first floor that calls for different temperatures at different times of day: At 5pm when it calls for 68 degrees on a very cold day, the 3rd floor could often go to 78 degrees. So the thermostatic radiator valves could be be set to 68 on the third floor so they those rooms don't over heat.
At 10pm the Thermostat calls for 65 degrees so the first floor would get cooler, while the 3rd floor would still stay at 68.
I suspect installing thermostatic radiator valves would cost a lot less than totally re doing the piping in the basement and breaking up the house into 4 or 5 zones… what do you think?
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