Replacing an old heating system

EricJC

I would like anyone's thoughts on my plumbing project I will be undertaking. I am working on a 1910 Victorian home we purchased last summer. It has hot water radiators in all the rooms. They are large and intrusive and we are replacing them as we remodel each room. We were going to add Runtal 8 ft UF-3 Baseboard Radiators to replace some of the old cast iron radiators. I was going to use 1/2 pex-al-pex for each loop individually to a hot water manifold I was going to put onto the boiler. It looks to be a bit pricey to do this and my father wants to save some money so he wants to put slant/fin baseboard which is much cheaper. I was worried if we do that the system will be very unbalanced until we switch all the rooms to it which might take 2 years as we remodel rooms. I think by making individual zones from the manifold with thermostats for each zone I can balance the heat better. I will be removing all the iron pipes and running the pex to all of the existing radiators. If we go with the slant/fin i would probably use 3/4 hePex instead as I think the connections would be easier to make as I think I can put the pex directly to the ends of the slant/fin. Any comments and questions would be welcome so I can get a better understanding and idea of the scope of the work I am taking on. It has been very hard to find a plumber who wants to come and do the work. One plumber was going to come during our first room. He never showed. I cut the old radiator out and removed it and replaced it with a steel panel radiator. The one guy we did manage to get to show up between when I cut the old radiator out and installing the new one said he would come back and install the radiator and would give us a price. He then capped the pipes I cut (I wasn't there my father was but they didn't need to be capped as they were being removed and they had shut off valves on each side of supply and return then charged him $300 and never called or returned calls again). Sorry for the rant.

pecmsg

How are you determining the BTU/h loss of each room?
How are you determining the Emitters output @ X°F?

Had I been there I would have capped those lines also. Not going to accept the responsibility for What If down the road!

EdTheHeaterMan

Will you do a room at a time next to each other? If that is the case, then make 2 zones. Old system on one thermostat and new on a separate thermostat.

You are correct in stating the baseboard will heat differently than the old CI Rads.

You might find this publication helpful.
http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf

mattmia2

Also note that the cast iron radiators will be most comfortable and even, panel radiators will be next and fin tube baseboard least comfortable and even. There are lots of panel radiators that though not as heavy as the runtal are much less expensive and are still a lot better than fin tube. The cast iron and the panel style radiators emit a fair bit of radiant heat, fin tube baseboard emits almost no radiant heat. The cast iron radiators stay hot for a long period of time evening out temps between cycles, the panel radiators have some mass but not a whole lot and the fin tube has virtually no mass.

EricJC

I have worked on btu/h loss per room. It is changing though as we reinsulate the room I determining what each room would probably ideally need to be comfortable. The rooms radiators were a bit overkill this past winter. The old radiator in the room we are working on now seems to calculate to over 10K btu/h for a
10x12 room with 8ft ceilings. It was like a sauna when the downstairs was at 70f. The new baseboard will put out 610 BTU/h per foot we are looking at 12ft for the room. I was going to put in a 6 zone manifold with individual thermostats for each zone.

EricJC

I understand you mattmia2 and agree but the space and room positioning in this old house is more important to my mother then the long heat you get from the radiator. She does like that heat the best but she wants them gone she doesn't want to see even the panel radiator on the wall. In the mud room we replaced a cast iron radiator with a steel panel one but that is an exception since it was off to the side on an outside wall and she didn't care as much about the mud room. The aesthetics is more important to her for certain rooms then the comfort. The nice this is we have split minis for ac/heat if a room isn't as comfortable as she would like it.

EdTheHeaterMan

EricJC said:

I understand you mattmia2 and agree but the space and room positioning in this old house is more important to my mother then the long heat you get from the radiator. She does like that heat the best but she wants them gone she doesn't want to see even the panel radiator on the wall. In the mud room we replaced a cast iron radiator with a steel panel one but that is an exception since it was off to the side on an outside wall and she didn't care as much about the mud room. The aesthetics is more important to her for certain rooms then the comfort. The nice this is we have split minis for ac/heat if a room isn't as comfortable as she would like it.

Wow, that is a contradiction in aesthetics. preferring a bump on the wall at or above eye level is preferable to a cast iron radiator. Perhaps you need to look at some different radiators and/or radiator covers that will make your heating system less obtuse and have more funds to spend on other aesthetics.

I can't believe that someone would really believe that 20+ years of comfort is less important that a photo op for House and Garden magazine. But that is just me.

EricJC

Up on the wall near the ceiling for a split mini versus a window or through the wall air conditioner she isn't as bothered by she wants to be able to put furniture against walls and not have her grandchildren burn themselves on the radiators. At there current home they have the slant/fin they are use to that. I only visit once in a while but I like the idea of being able to control the heat in my bedroom. The way it currently is I will have to crack a window in the winter as they like it very warm.

EdTheHeaterMan

EricJC said:

Up on the wall near the ceiling for a split mini versus a window or through the wall air conditioner she isn't as bothered by she wants to be able to put furniture against walls and not have her grandchildren burn themselves on the radiators. At there current home they have the slant/fin they are use to that. I only visit once in a while but I like the idea of being able to control the heat in my bedroom. The way it currently is I will have to crack a window in the winter as they like it very warm.

That only happens once in my family. Kids are pretty smart at that young age. When they get to their late teens... That is when you need to worry about them being stupid! But they usually grow out of that phase by say 25 years of age. And amazingly, you also get a lot smarter then.

Hot_water_fan

Also note that the cast iron radiators will be most comfortable and even, panel radiators will be next and fin tube baseboard least comfortable and even. There are lots of panel radiators that though not as heavy as the runtal are much less expensive and are still a lot better than fin tube. The cast iron and the panel style radiators emit a fair bit of radiant heat, fin tube baseboard emits almost no radiant heat. The cast iron radiators stay hot for a long period of time evening out temps between cycles, the panel radiators have some mass but not a whole lot and the fin tube has virtually no mass.

Mass isn't much of a problem. If desired, this home run distribution could be used with constant circulation and ODR which would keep the water flowing at the temp needed to satisfy the load 24/7. Basically instead of using weight to even out the temperatures, you can use other methods.

pecmsg

In 4(0+ years I’ve never heard of someone getting Burned by a radiator. 212* or less for steam. 180* or less for hot water. 

If you size for what you have now you’ll be oversized down the road. 

Hot_water_fan

Any comments and questions would be welcome so I can get a better understanding and idea of the scope of the work I am taking on. It has been very hard to find a plumber who wants to come and do the work.

Future you will probably thank you if you size the radiation for SWT of 120 or lower, that puts you in the sweet spot for high efficiency appliances. The scope of work is significant! Make sure it's worth it to you, there will probably be no financial recouping of the time/materials.

mattmia2

If rooms are overheating then you need to balance the system which is relatively easy with hot water unless the emitters are plumbed in series. You probably would do well with making lower temp water to supply the radiators especially if it started out as a gravity system.

EricJC

Yes they are plumbed in series right now with branches running everywhere with large iron piping that gets stepped down as they branch out. Yeah I have thought about trying to find a way to lower the temp this is a pretty old furnace. I have to look at who makes it on the weekend. I have had a very hard time getting anyone to do work at our home I feel like there is a shortage of plumbers. A few a called told me they are booked a 2 months out.

mattmia2

Are you sure that isn't piped with a separate supply and return main? It looks like a converted gravity system which would have to be separate mains or early diverter tees which you could balance either topology with the valves on the radiators.

Because of the amount of water in that system you would have to be careful about turning the water temp on the aquastat down because it would likely cause sustained condensing in the boiler.

Jamie Hall

Just from that picture of the pipes in the basement I'm almost certain this was a gravity system. They worked like a charm and were incredibly reliable -- no moving parts to speak of.

However, it also looks as though at some point someone tried to convert it to a pumped system. This can be done -- but it can become difficult to balance the system without a fair amount of effort, and I don't suppose that effort was put in. It is, however, a good deal easier than changing to all new, and you could still do it if you didn't fear the radiators.

Now. All that said. It's going to be a lot of work, and while it is in progress you will have uneven heat. I would take out all the old piping -- every foot of it -- and repipe with careful zoning with home runs or at the very least reverse return in each zone, with each zone having its own home run. Do not mix emitters in a zone -- if the zone is panel radiators, all panel. Baseboard? All baseboard. And so on.

On the "plumber" being two months out -- not a bit surprised. Anyone competent will be.

Oh -- and one more thing. This isn't a job for just any plumber. You are going to want a really well qualified heating professional.

EricJC

Yeah it is now a pump system with pipes branching everywhere and then going back into one return back to the boiler. As much as I don't like it my father wants to go with slant/fin in all the rooms eventually. but in the beginning we will still have a lot of radiators and may even keep a few if it my mother can work around them. I am looking to cut all the piping out and run 3/4 hepex making homeruns for each zone. on the 2nd floor there are 3 bedrooms each bedroom will have it's own zone and thermostat. then the attic will have its own zone. finally on the first floor the mud room and bathroom will be 1 zone the kitchen it's own zone then the den and dining room it's own zone and the living room and hall way on a zone having a total of 8 zones and 8 thermostats I am looking at putting a Cross Manifold 8 zone to control and balance the new system

Hot_water_fan

You could also use TRVs instead of 8 thermostats. 

Just to be sure before more pipes get cut: what’s your anticipated spend on these changes? 

EricJC

Yeah TRVs aren't much cheaper then the thermostats plus where they are located on the floor make them a pain. Plus they don't control the boiler and pump correct? I would need something to tell the boiler to heat on demand for each room or zone. As for how much we will spend that is hard to figure at the moment. The manifold alone is $1k. Probably 2 500ft of hepex for another $1.2k then the baseboard per room. probably $250 per room in the beginning. I wanted to use the Runtal steel baseboard but my father wants to cut the cost there with the Slant/fin crap. I figure for the heating this year probably about $7-8K depending upon what tools I will need to buy.

Hot_water_fan

May I suggest a pause? There’s a lot of different ways to do this. If you’re in need of assistance, I suggest using this site to find a contractor. If it’s your plan to do the work yourself, Caleffi Idronics journal will answer the questions you’ve posed this far and the others that will inevitably arise as the process continues. There’s a cost difference between slantfin and runtal, sure, but it’s pretty insignificant compared to the rest of the costs, financial and time, involved with this. If Runtal’s a cost problem, there will be a lot more cost problems. 

Jamie Hall

I suspect your costs are low -- perhaps very low. There are always unexpected expenses which you have not figured in.

EricJC

I love the idea of a pause. unfortunately my mother is the queen and we have to redo these rooms either way and have already started opening walls to run new lines as there are currently pipes running up the walls in all the first floor rooms and those pipes have to go during these room renos. The old paneling in the room has to come down and sheetrock has to go up. The nice thing is I have time until the fall hits to get all the loops together and then put the manifold together. How it is all going to be when I am done is anyone's guess. As for money my father is just trying to save where he feels he can with the slant/fin. He won't go broke doing this he just wants to conserve if he can. He knows we will have unexpected costs which is why he is saving money with the cheaper radiator. He also feels it will be easier to add some more baseboard to a room if he doesn't feel it's comfortable enough. We just spent about 8k on the Mr. Cool DIY gen 3 36k split mini systems covering 6 rooms. 3 upstairs so there is 1 in each bedroom and 3 on the first floor. That went pretty well. We had a new panel put in first so we had the capacity for the 2 45 amp breakers.

Hot_water_fan

Exciting! The Idronics series will be very helpful here.

clammy

Take a look at cross manifolds . They have every thing you could need in a neat little package and I feel much cheaper then building a manifold and then adding a zone controller . There flow rate per zone is only 2.5 gpm I believe but if your micro zoning w not to large load there great . On the micro zoning unless your using a modulating boiler I would think about a buffer tank to help prevent short cycling from small zones . As for baseboard I put it on my bottom of the list of heat emitters especially in older homes usually there just screwing them to the face of the trim other wise it usually requires some trim removal ,plaster repair ,paint and all that jazzy stuff , The #1 thing on panel rads amongst others is this only one box is brought into a room requiring one radiator , easier to install no trim removal on most retro fitting jobs ,run 2 1/2 pex lines to one location and connect your done ,room by room temperature control non electrical w trv s installed on wires to run or zone valve so . Can attach to a uponor ep manifold ,fairly inexpensive and your done . On high temp system there cost per btu output coupled w individual temp control via trv s on panel radiators as compared to a baseboard system equally zoned would easily require more time and material cost as per thermostats , zone valves ,zone valve controller and running of thermostat wires . But my biggest pet peeve w baseboard in old homes is the loose of the trim mounding and that usually after 10 years or so there full of dirt and dust w the cover falling off w furniture right up against them and carpet up against the cover limiting its output further .
I ve had customers feel the same way about panel rads at first but after a short time they said they didn’t even notice them but that there home has never been so comfortable that they don’t even know when the heat was on or off they just know they where comfortable . Peace and good luck clammy

EricJC

Yeah I have already started reading some of the Idronics series as I was searching out how to begin.
Yeah I mentioned the cross manifold above that is what I am looking into to do all this. Each room is getting remodeled so trim is no matter. Yeah a buffer tank maybe needed I will find out in the fall. I will be using 3/4 hepex with the expansion fitting where I can. The uponor manifold is another option I am considering. There is no carpet in this house so that is kind of nice from that aspect. it is all hardwood or tile. The nice thing is if it goes completely wrong we have the heat from the Mr. Cool to fall back on.

Hot_water_fan

This has great potential. Homeruns allow you a highly customized and efficient system, especially when combined with the modern boilers, circulators, etc, but will have benefits even with the existing equipment. The boiler is most likely wildly oversized and odds are the room by room calculations will be too, but you can sort this out a bit with controls and buffer tank.

Tinman

Hot_water_fan said:

Also note that the cast iron radiators will be most comfortable and even, panel radiators will be next and fin tube baseboard least comfortable and even. There are lots of panel radiators that though not as heavy as the runtal are much less expensive and are still a lot better than fin tube. The cast iron and the panel style radiators emit a fair bit of radiant heat, fin tube baseboard emits almost no radiant heat. The cast iron radiators stay hot for a long period of time evening out temps between cycles, the panel radiators have some mass but not a whole lot and the fin tube has virtually no mass.

Mass isn't much of a problem. If desired, this home run distribution could be used with constant circulation and ODR which would keep the water flowing at the temp needed to satisfy the load 24/7. Basically instead of using weight to even out the temperatures, you can use other methods.

And add a TRV on each radiator. 

hot_rod

With a TRV system the delta P circulator will respond and adjust flow as the valves open and close, so no wires or relays required for temperature control anywhere in the building. The delta P function was developed for the Euro market which is predominately TRV-ed panel rads..

As for the boiler call, a small induction relay like this one from RIB, senses the pump revving up by its increasing current draw and closes a TT contact on the boiler. So the system is fairly automatic, proportional, and non electric except form the power to the pump and boiler.

I have not tried this brand of induction relay, the folks at RIB claim it works down to a .25A draw. I'm waiting for a sample. I've had mixed results with an imported knock off brand that has been hit and miss.

Another option is a single centrally located "master" t- stat to start the system. Or depend on ODR.

mattmia2

I mean potential relays/current relays have been used to start hermtic compressors for the better part of a century.

Tinman

I’m going with ODR every time. Everything in our house is automatic and we rarely adjust the TRVs. 

EricJC

Sorry it has been awhile since I have posted been busy setting up the new heat system going into the winter. We ultimatly found used burnham baseray 10" baseboards to install in rooms. I installed the Cross Manifold 8. The heat is working and I have wired all the rooms with their own thermostat wire. So each zone can call for heat as needed. It is working ok. The issue I am having now is it seems the water returning is much cooler then I would like. Is there a way to determine if the circulator is just to weak to move the water. It is on the return side of the piping pushing the water through the boiler. The water going out is very hot almost to hot but coming back it is much cooler. I was thinking of buying a different circulator to try. I have attached some pictures of what I have done. It isn't the prettiest. Please let me know your thoughts.

mattmia2

That vent looks very questionable. That could kill someone if it isn't right.

The mass of the system may require return water temp protection on the boiler. Does it heat the house? How did you size the emitters? If they are very oversized then they will heat the house before they heat enough for the the return water to get hot.

leonz

I am genuinely sorry to see a beautiful simple system like that butchered this way.

hot_rod

Are those 1/2 or 3/4 loops? How long? The is a pretty low head circulator, but with a cast boiler, cast baseboard and 3/4 tube it should be close.

What is the delta T on start up, what is it when it shuts down, or after 1/2 hour or so of run time. If the home is heating ok a 20-30 delta is workable.

I’d watch return as @mattmia2 mentioned. Within 10 minutes or so you want the return at 130F. With a wide delta, you may have to boost supply temperature up to get adequate return.
We need some numbers to better answer the question.

EricJC

It is a air seperator before the water goes out into the system. the water at the boiler is nearly boiling about 200F. At the mainfold going out it is about 185F coming back it is only about 120F. it is all 1/2 pex-al-pex loops various lenghts. The one that runs the most often is pretty short as it is the room pretty much right above the boiler. It is the living room there is a 10Ft piece of the burnham baseray then into another 4 1/2 ft of baseboard then into an old long radiator. It just seems that the water has no really circulation force. When I look at the return for that loop I see very little pressure and I have the loop opened all the way. All the rooms heat adequetly. The living room will eventual get 2 more pieces of 3ft baseboard as well. I fear the circulator isn't strong enough. It might have been better with the old giant pipes.

EdTheHeaterMan

Just wondering if the new piping is 1" copper. What is I=B=R Net rating? If it is over 80,000 BTUh, that may be your problem. When all the zones are calling at once, that 1" pipe can handle only about 80,000 BTUh. That boiler looks bigger than that. That booklet I referenced in my earlier post is no longer online. Here is a newer edition that is missing some sections, but most of it is there. https://www.xylem.com/siteassets/brand/bell-amp-gossett/resources/technical-brochure/fh-z100b-bg-zoning-made-easy-2.pdf. You might want to read pages 3 and 4 to get the idea about pipe size and how it relates to BTUh capacity. Basically you can't fit 10 pounds of potatoes in a 5 pound sack. Or something like that

So, What is the I=B=R Net rating?

mattmia2

What is the cross section of the inside of that manifold?

What do the individual flow meters on each zone read?

That hole through the wall is probably big enough that it should have a lintel. Or put a brick mortered in perpendicular to the wall every 16" or so

EricJC

I have been on Manifold makers website and I haven't found much info about the cross section of it. it does seem to indicate the manifold dimentions as 1 1/4. I went with
1 inch copper pipe due to the fact that the manifold had 1 inch npt valves for shutoff. As for flow meter I see almost no flow on return. Clearly water is going out an into the radiators but is just seems as if ther isn't any flow getting back i opened up the flow return on each zone all the way. The only thing I can think of trying next and replacing the circulator as I have no idea of it's age or condition. As for the hole I am not worries about it at this time it doesn't seem structure he seems to have put it up to seperate the boiler into it's own room. I was going to try the Taco VT2218 ECM High-Efficiency Circulator to see if that helps. The boiler is larger then 80K Btu I am certain but it isn't like I don't have enough hot water going out it just doesn't seem to be returning fast and I was wondering if the circulator is just to weak?

EricJC

the I=B=R Net rating is 93,900

mattmia2

That circulator is probably older than when @DanHolohan started selling them. Its condition is probably good if it isn't leaking and isn't making noise. It was sized for a gravity conversion so it is probably selected with a curve with not a lot of head or flow. You probably need a circuator with more flow at higher head. A modern ECM circulator will use less power too.

mattmia2

What are the flow meters capable of reading and what flow did you calculate you needed in your emitters?