Excited about Boiler Design
EDIT: I probably should have continued this thread I forgot I had started back in early 2022.
Nearly 3 years later I am finally making some progress on it, and I started this new thread ….
On one side of the house, we have a porch with crawl space and the basement chimney goes right through it. That’s where the largest basement room is currently and the Weil McLain CGa 7 Gold and two water heaters utilize one half of the fireplace chimney. It’s a good spot for a hot boiler. However, most of our water use is on the other side of the house that also has the floor drain. So any leaks in this semi-finished area of the basement with the boiler and water heaters just runs across the whole darned floor. I want to install a modcon on the other side of the house, maybe a combi, and maybe a storage/buffer tank and maybe a hot water storage tank and/or heat pump water heater for summer hot water. Part of this move is to also free up the chimney to be able to burn wood. Hearth.com also got me excited about maybe even adding a wood boiler there. I’d like to put a pool/ping-pong table over in that area of the basement too. Maybe just a wood stove makes more sense.
So I am thinking that, at least for the short term, I want to make a large primary loop for the boiler so I don’t have to re-pipe every radiator and all the zones. That honestly might make sense in the end, but makes the project monumental. So I am thinking I can add the modcon boiler on the other side of the house, add the big loop, and just swap the connections with the existing boiler. I would think that doing this all in PEX would be economical, and also make it very easy for me to alter in the future. I don’t think I want microzones, but perhaps a buffer tank would enable that if desired.
I see some say primary loops should not be done with PEX, at least not close to the boiler. Does anyone have a strong opinion on this? Also, I am only familiar with smaller PEX sizes, and honestly I’ve never seen or worked with anything larger than 3/4”, having tools for 1/2” and 3/4” for potable water. So working with PEX in 1” and up will be new to me.
I am in love with Triangle Tube products and am now debating over Instinct Combi 155 and 199 which seem just so darned cheap it’s scary. One reason I like the Combi idea is because I want to buy an identical unit for my 2 story garage / pool house project. That would mean I’d have parts ready to steal from the garage in the event of a failure. The garage isn’t somewhere I really want to have a tank, and it’s only got a cold water line out to it now. Hot water line from the house just ain’t gonna happen, but I do have a spare 2” electrical conduit from the house to the garage. So it’s not impossible, just not likely.
I would be interested in hearing the opinions of others and wonder if I should put together some diagrams or photos and videos to help get advice from others.
I am really excited about building my Raj mahal of hydronics.
Another thing I am curious about is if we should try to staple floor heating under about 1.5” of wood flooring from the basement. Currently we have cast iron baseboard heaters (not original to the 105 year old house) on 90% of the first floor that is on its own zone. With all the cast iron plus the boiler in the basement, it gets to 76-80 F down there, which I’m sure is a real waste of energy. Putting my winter office down there might save some heating though.
Anyway, I’m looking to design my dream system for my dream house. Thank you in advance for any help I receive here.
Some older exterior pictures are below to get a sense of what I am working with.
Comments
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anybody here work with wood fired boilers? I think that would be cool to have a second boiler added to the primary loop to be able to heat with wood. Unfortunately, I doubt that any of them are as pretty as a wood stove. https://www.hearth.com/talk/forums/the-boiler-room-wood-boilers-and-furnaces.13/
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Well… the project is certainly feasible. The biggest problem with PEX — any size — is that when it's handling hot water (even domestic hot water) it pretty well has to be in a trough or hung at very close intervals to avoid sagging. It is rated for use up to 200, but the manufacturers aren't really happy over 180, but that's high enough for your use case.
Insulate the dickens out of it. You don't want the heat just wandering around!
Size it for the BTUh load; even one inch may not be big enough.
I at least would be very cautious about an indoor wood boiler, unless you have a captive firewood supply like your own woodlot — and the time and energy to make you own wood. You can do some figuring on costs, though: most eastern hardwoods run around 24,000,000 BTU per cord, so you can do some math and compare the cost per BTU to whatever you are using now. A cord of wood is more or less equivalent to 150 gallons of fuel oil.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
Wow. A cord o wood equal to a gallon of fuel oil. We have natural gas here, something I may have neglected to mention. I guess a wood stove for ambiance and extra heat probably makes a on more sense than messing with an indoor wood boiler. I have yet to find any pretty ones. Maybe for the garage near the swimming pool it could make sense to be able to heat the pool with biomass instead of natural gas. So I will maybe keep researching that a bit.
For the piping size, I think my existing 210k btu in, 175k BTU out Weil McLain CGa 7 has 1.5” pipe. I guess I could just use whatever is on the boiler I buy though. It looks like each of these combi boilers have 1”. So maybe that’s all I will need. Perhaps there would be less heat loss with larger pipe though. I didn’t know.
https://triangletube.com/products/gas-condensing-combi-boilers/instinct-wall/I can put the pipe on top of 2x4 to support them around the basement, maybe up in the joists. So I don’t anticipate that being a major concern.
As for temperature, I never ran anything over 155 F in my old house. I assume this house will be the same, but if I was to run an indirect water heater, I guess that loop would get hotter probably. That would be next to the new boiler in the existing laundry room though.So this is all sounding doable.
I am curious is those TT Instinct Combi models will have the ability to have an indirect tank attached with a higher firing temperature for DHW. I’m not expecting them to have this, which is the only thing holding me back from purchasing one of those Combi models. Also deciding between 155k and 199k and being concerned that they are made with inferior quality parts. I was very happy with 14 years of TT Presige Solo ownership but always used a standard gas water heater. This will be my first time ever trying anything else, and I am looking at all the following:- tankless in a combi
- Indirect fired
- Heat pump for summer hot water
- A hot water storage tank to assure we don’t run out or have flow rate issues. Not exactly sure how to do this yet.
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My opinion as an installer, if you want the best long term system, don't do a combi. Yes, they work and I put them in, especially for small houses or apartments, but I consider an indirect a superior option.
My opinion as a long time heating-with-wood person is, don't do a wood boiler. If you want to burn wood get a good looking woodstove and fire it up on that bitter cold weekend that you are planning to spend at home. Nothing beats a cheery fire while the snow flies outside. (Well yes, love at home beats it but why not have both!)
As for triangle tube instincts, they are fine. However, they do not have near as many setting options as most manufacturers and do not modulate as low, but the argument could be for their simplicity. They do not have settings such as differential, time on minimum fire and time to max fire. Those settings can greatly mitigate short cycling even without a buffer tank.
And yes for a HPWH if you have the proper criteria to take advantage of its features. They do great for summer HW in an unfinished basement where they also help with humidity.
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so if an indirect is superior, and I don’t want a tank in the garage. Then the concept of buying an identical unit goes out the window. It might be cheaper to just buy the “most-likely-to-fail” parts like a did for $500 a few years ago for the TT Presige Solo 110 at the old house.
On the old stove, I actually already got two VC Encore units, one for the garage and one for the basement, but have less than $300 into the pair at this point, so I can pivot. The garage boiler really is not needed any time soon, especially if the wood stove is up and running. I am thinking that o should buy the replacement boiler for the house this year, but I guess my improvements today might help me get through the winter.
today I added the Taco SR503-EXP to my boiler to be able to run wireless Internet thermostats and also have the boiler shut off when no zones call for heat. That might help my system run a bit more efficiently and at least enable me to up the boiler temp now if I want (without getting all the popping and banging due to the lack of a primary loop and t-stat shut off
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Travel over to the ISH show in Frankfurt this March. They have an entire hall dedicated to solid fuel burning stoves and boilers. Cordwood, pellet, chip, biomass fuels.
Parlor boilers are designed for the ambiance and a small hydronic load. Hundreds of them from countries around the world on display. It is a hot Hall as many of these units are actually running.
Some examples from Austrian manufacturers
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream
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Why is it that we here in the US can't seem to make or decide not to make an attractive wood stove? They all seem to look like a television from the 80s or an attempt at redesigning the Franklin stove. If one likes that look that's fine but the real attractive options (to my eyes at least) are all coming from eastern and northern Europe.
Those are beautiful @hot_rod
Miss Hall's School service mechanic, greenhouse manager, teacher, dog walker and designated driver
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I hear the logic on not buying a combi, but I think my garage / pool house project will be a place where I don’t want a tank of water I need to keep warm (from freezing). So I think I have decided to buy ONE TT Instinct 199 Combi to put in the house, and if it doesn’t work out, I can move it to the garage and do something else. Meanwhile, I have told my family what I want for Christmas and sent the link.
My next step will be acquiring parts I am going to need for the install.- primary loop piping to get to the old boiler location
- expansion tank,
- Condensate drain setup, etc
- Organize laundry room and reconfigure the washer dryer, etc.
I’ve got a lot of junk to eliminate, and perhaps my highest priority for this project will be setting up an office in the basement for this winter where I can sit toasty next to the boiler (saving even more money keeping the house cool). There are also drafts down there I need to address. It will be a great project space, and I think my wife will appreciate me cleaning up my first floor office.
I will report back here when I am ready to design tank storage for the hot water and digest stuff like this link.
I think I will also start trying to educate myself on heat pump boilers to have setup in the basement for next summer. Also, finding the ideal location for a heat pump water heater in the basement will be on my list. Do I put it close to electric and fixtures, and maybe add fans to circulate basement air? Or do I just put it close to the main room that I hope to finish and make livable space? The warmest area of the basement would clearly be the best place to extract heat. It almost makes it sound like putting it on a higher floor in the house could be a wise move (aside from the potential for leaks and complexity of altering plumbing). I don’t know. But I will learn.
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Nicest wood stove I had to play with was a Jotul 601. Simple. Straightforward. Worked like a charm. heating about 800 square feet of space in Vermont in the winter…
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
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So I see boilers are selling out, and I was about to click “buy now” on the 199k BTU input combi, but figured I should look at whether the minimum firing rate would be too high. Oversizing it would be bad.
We do use natural gas for the cooktop and recently added an outdoor grill, but I think that the grill is negligible during the winter months, as I encourage indoor cooking when the heat is on and outdoor cooking when the AC is on.
I took our CCF / mo for the past 12 months and then saw that 6 months November to April are when all the fuel gets used for the most part, 1244 CCF vs 186 CCF anyway. So if I want a boiler to run at its minimum firing rate for 6 months straight to provide hot water and heat, I’d want to break down the 1244 CCF into the hours. I come up with 29.5k BTU INPUT consumed per hour. We have an 83% efficient boiler and probably 60% efficient water heaters: if I just use 80% as a guess at our efficiency, then the OUTPUT that the house consumed was actually 23.58k BTU/hr.
I see that the 199k BTU Combi would likely be a bit oversized with a minimum input of 25k BTU and 95% would be 23.75 k BTU.I do hope to make the house far more efficient in the future. So there’s consumption should really drop, especially as kids move out. So that could be another reason to reduce the size.
So there’s a balance between quick recovery and endless hot water (all provided by the boiler) and efficiency:
I have setup a desk in the basement next to the existing boiler and two water heaters. 210k BTU on the boiler, and 40k BTU on each of the two water heaters. I primarily have the second setup as a storage tank though. So even though we have 290k INPUT BTU of heating power in this basement, it’s only fair to call it 250k BTU.I think we could get by with the smaller 155k BTU input combi, but I think I am going to be safer with the 199k BTU one, and if it fired for 6 months straight at its lowest firing rate, it might actually be perfect. I just don’t know where we’d be able to store all that heat to make it through the coldest moth.
So I looked at the coldest month, ending Feb 12. 306 CCF /31 days = 42.7k BTU/hr.
If I was able to store heat, it looks like ~43k BTU/hr input would have gotten us by, like a 55k BTU/hr combi boiler at 80% efficiency running at 100% firing rate all month would have been ideal I guess. The problem with that sizing is that it least zero room for ramping of the heat.
Last year I kept the house very cool when possible to minimize heat loss. I know ramping up could consume more, but I am certainly doing more of that this year. We also kept the heat in the den essentially off and closed off the room. I am about to insulate so we can hopefully use it this year. I don’t know how that balance will play out.
I think I’m going to buy that 199k BTU boiler before it’s gone. Wish me luck.0 -
I clicked the “buy” on the 199k BTU Combi. I will plan on also adding a storage tank after the Combi for DHW. I think that the most ideal setup will be to have a heat pump electric water heater to make cool in the basement that is used primarily in the summer. I’ve read that a regular electric water heater is just fine for this. So maybe I will consider that route also. If I went with regular electric, I could also set it at some minimum acceptable water temp for year-round use and also maybe save a few bucks. So this will be something to think through. I have two gas water heaters that could also be used for nothing more than tanks too (since I believe I will want to move them far from the chimney, making room for the wood stove.
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I looked at my hourly usage over the last year nd discovered there’s only about 3 hours where we used more natural gas (cooktop, two 40k BTU hot water heaters, and the 210k BTU boiler) and I discovered there’s only were only about 3-5 hours during the entire last year when we used more than 1.5 CCF. So I initiated a cancellation with the seller and will see if I can get my hands on TWO 155k BTU combi units, one for the house (with a DHW storage tank/electric/heat pump water heater, and one for the garage as straight up tankless DHW where I may look to also use pool water as a heat sink maybe with a tank in the garage for that. Not sure if that’s a terrible idea with the pool chemicals, but that heat exchanger would need to be deigned right. The problem with the garage is not having enough heat emitters. So that could be interesting. But I do want to get two identical units. I totally forgot about that when I clicked Buy hastily this morning when I saw only one boiler remained. No rush here (I don’t think anyway).
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OK. Buyers remorse situation resolved. They refunded me, and I placed the order for TWO Instinct 155k BTU Combi boilers, one for the garage, and one or the house where it should be the most efficient option, feeding into a Heat Pump water heater as a winter storage tank, and summer hot water producer. It could also be used to help balance the load. If the Combi has issues with hot water flow rate, I may need to figure out a way to have some amount of water bypass the Combi and go into the get pump water heater to make up the difference. But maybe it will be perfectly ideal to help assure the hot water usage is under control. I’ve got 3 teens in the house right now.
Anyway, figuring out what her pump wat hear to purchase will be coming up next.
The per topic will be a buffer tank for thermal mass storage to be able to handle microzones. How much do I need? And is an old natural gas’s hot water heater sufficient? I’ve got two of them I. My basement that I will be planning on eliminating. I can wrap them in insulation like nuts and keep them in the laundry room where there’s a floor drain in the event of disaster. I bet they will last much longer if they have the lower pressure heating water in them AND they are not subject to fire that they get every day. I can also be sure I design everything so it’s easy to remove a single component with valves that assure the ability to bypass o include optional components in my install. The buffer tank(s) would be one of these I the heating, and the heat pump water heater would be another in the DHW.
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Two Triangle Tube Instnct 155 Combi boilers “purchased” and will be waiting a while for hem to show up.
One will go in the garage where I aim to create a studio apartment above he garage with one full bathroom, and downstairs in the garage have a kitchen, plus n outdoor kitchen / grilling area. I don’t plan to have any storage tank for hot water, just rely solely on the combi for DHW. I will probably have four total radiators, cast iron ones I already own.The more important Combi will go I. The house where I believe it is sized right based on my hourly consumption over the last year, with only over 1.5 CCF / Therm getting used in ~3 hours over the course of the year. 1.7, 1.8 seemed to be the numbers, and that includes cooktop, 210k 83% efficient boiler, and two 40k BTU water heaters. If I implement a storage tank f the DHW, I think the 154c will cut the mustard. Plus, if I need parts, I can steal from the garage unit that will be identical.
Deciding on a heat pump water heater is next.
Also, deciding on buffer tank(s) and if I should use the two natural gas water heaters I’ve got, just because I have them… that’s also on the list. He price is right.That would only leave me with the cast iron Weil McLain CGa 7 Gold 210k in, 175k BTU out boiler in good shape to sell. I might be able to get a few hundred bucks for it. I don’t know. I might as well guess a shot at getting it up for sale, but maybe I better wait until I at least have the TT hub on the wall first.
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are you talking about trying to redesign systems unnecessarily? Or are you talking about trying to DIY design and install all the stuff?
on the first question. This is more of a renovation that I don’t expect to save me that much on a monthly basis. Rather I am making long term plans for the future with the renovations. I am creating usable living space in my basement and in my garage. The garage could possibly be rented out and make back all the money in short term. The basement is just something I want to do. Ripping out the High Velocity ductwork for the AC and redoing that will be ANOTHER project too. This is our dream home, what I call “a worthwhile project.”
On the DIY, I want to get what I want, not what someone wants to sell me. I am not opposed to hiring people to install what I buy, but I will likely make all the decisions because I had a terrible experience with the last pro I hired for a modcon inatall, teaching him everything he knew about modcon boilers by the end of it all.0 -
I feel it’s time to start researching heat pump water heaters. I should not NEED one for the house, but I want to know what is available on the market. So here are a few I have found.
Stiebel Eltron (very expensive):https://www.zoro.com/stiebel-eltron-water-heater-heat-pump-80-gal-233059/
Rheem:
NY Times likes the Rheem it seems.
Edit: TWO THINGS are making me second guess this whole heat pump water heater thing.- Not a wide variety of products / vendors I am finding and high prices. Yeah, $1700-2500 isn’t terrible, but bc I only plan to use this as a storage tank and summer water heater, this feels high especially compared to the cost of the combi.
- One of the 120 Volt versions I saw had a map showing that it’s not a good product for my area, only good for the south. Using electricity to steal heat made by the heater is two steps to get the water hot and can’t be too efficient. I. The summer time when you are trying to get rid of heat, I understand it must be more efficient.
Anyway, I am starting to think I can postpone the heat pump water heater portion of this project a couple years down the line and probably just use one of my two existing water heaters as a DHW storage tank or maybe pickup a cheap electric water heater. I wonder if I need a special tank with an aquastat shown here: https://www.bradleycorp.com/sizing-tankless-water-heaters/on-demand-water-heater-with-hot-water-storage-tank
I wonder if the other water heater can be used for heating water storage. I will have to see if I can find a diagram to follow for thermal mass storage.
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some useful info regarding HPWH,s
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
OLD CAST IRON SETUP:
I've been following this one on the DIY forum where someone is asking if setbacks are as efficient as constant temps with a cast iron boiler. It really has me thinking and observing this boiler next to my basement desk.Help me solve this energy debate! | DIY Home Improvement Forum
Even though I have placed an order for a modcon combi, I am currently struggling through the concept of keeping return temps over 130 F on my cast iron boiler. When 130 F is all I need to heat my house, my thermostats will never call for heat if I have radiator temps that high. So my system really needs a primary loop that it can keep hot, which isn't an option bc my boiler is piped without a primary loop. I guess I could start turning off the knobs on the radiators around the house so I've got fewer emitters, but it seems to me that maybe what I need to do is go with the setback approach of the OP. Let the house cool off for a long time, and then heat it up for long periods. If I had the ability to program lots of periods per day, I could basically have the boiler on for an hour, off for an hour. I'd probably end up heating the house to 80 F and letting it drop to 60 F and repeat. The OP's system seems to gain 1 degree per hour, while mine seems capable of gaining more like 4 degrees per hour I think. So maybe that 60 and 80 could be more like 65-70-65-70 all day long.
Seeing this makes me glad I'm converting to a modcon. I don't know how people live with 180 F boiler temps and the temperature swings they create. The modcon solution seems so darned simple to drop temps, get higher efficiencies and basically a better level of comfort with more constant temps.NEW MODCON SETUP:
One thing that I am struggling with a bit with the modcon concept is the buffer tank and the fact that the outdoor temps and therefore the target temp is going to vary though the day. With a well-balanced single zone for the whole house (like the one I just sold), and pipes that aren't huge with tons of thermal mass, I would think the dynamic temps would be easier to reach. But I've read that microzones can be a problem and have thought about adding a buffer tank. Determining the right size buffer tank doesn't sound all that simple. I guess a smaller tank might fit better with a varying temp outdoor reset Modcon.
For me, I've got two 40 gallon natural gas water heaters I won't need (2016 ane 2001 installs, currently onlyfiring the 2016 install and using the 2001 install as a holding tank for the hot water, maybe firing only when we have NO hot water left). One might be good as a tank to store DHW post-combi, but the other might be available for a buffer tank. 40 Gallons might just be too ig though, and perhaps I should track down a smaller tank. Anyway, I am trying to research this buffer tank concept. Clearly it would be good to have on my current cast iron boiler, but that will be going away.Here is a video where I was perplexed by the piping and also the 30 PSI releif valve that I thought was too high. I guess not though bc the CGa manual shows 30 PSI is correct.
https://youtu.be/ri6yzXmKgIc?si=jguIpP-f2yb8012R
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If anyone NEEDED a competent professional to evaluate your system and make reasonable recommendations its you, based on your loooong posts of uncertainty that add nothing to solutions ( Quote from you "So I see boilers are selling out" are you a salesman?) - just sayin
Do yourself a favor and Please! check out find a contractor on this site
Regards,
RTW
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Blah Blah Blah meaning:
"It’s often used to signify boring, empty or overlong speech."
Go back and read the posts
Regards,
RTW
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I see that Langan's in NJ offered to do a call with me a few years back. The only ones I see that don't look too far from me are the following in PA, probably about 1-2 hours of driving for the contractors to come see my projects. But at this point, I think I will continue my research to figure out more of what I THINK I should do, and maybe read the manuals for the Combi boilers that I have ordered when they arrive. This is not a rush project, as it got conceptualized nearly 3 years ago and has just gotten its wheels in motion now.
S D Hansell Co(610) 356-5806
3601 Winding Way
Newtown Square, PA 19073Full service provider of Plumbing, Heating and Cooling services since 1962.
Started by Sellers Donald Hansell and continuing with son Rick and grandson Pat.Pompetti Heating & Air Conditioning, Inc.(610) 565-4778
PO Box 1649
Media, PA 19063A family-owned and operated heating & cooling company. We provide our customers with the most reliable service and products in our industry. We specialize in all type of hydronic systems, including solar hot water, geothermal, radiant, hot-water boilers. W…1 -
I am studying up on the TT Instinct installation guide. The garage install will likely be simple, but bc I may use the boiler for pool heating, I guess it will also have multiple zones, but it will not have a storage tank for DHW. I do THINK want to add a tank for DHW storage in the house though. So the following diagram will probably get mixed with the bradleycopr one though. https://www.bradleycorp.com/sizing-tankless-water-heaters/on-demand-water-heater-with-hot-water-storage-tank
One (of many) things I need to learn is the apparent mixing valve between hot and cold water on the hot DHW line. I don’t think the TT diagrams describe every component, but I do plan to make sure this boiler is piped correctly (unlike the current cast iron one in my house).
I am probably beyond asking for favors here, but I will document here what I believe I learn.
So what is this circled in yellow?
Also on this topic of DHW and a storage tank. I am thinking that I want to do a heat pump for storage long term, maybe just use one of my existing 40 gallon natural gas tanks (with no heating) short term, but I have to admit that the wheels are turning wondering if an indirect tank could possibly be connected to this combo unit. Having the ability to keep the stored water warm for long periods might be a requirement, requiring either a loopback to the tankless, maybe resistance electric heating, or indirect heating methods. My assumption is that you can’t reach those 95% efficiency numbers with DHW bc you typically want DHW to be 120+ F. I don’t know. I AM LEARNING.
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AIR CONDITIONING HEAT INTO DHW:
On the DHW side of things, especially for summer DHW heating, the concept of being able to pull heat from the AC Condenser would be great. This could be a reason to have at least SOME type of indirect heating of cold water that comes from the AC coil.
Since we have a swimming pool, it’s possible that we could put the heat there, but it would probably just contribute heat to the pool when it’s already bordering on too-hot, as it got above 90 F with my passive heating this past summer.
However, perhaps there’s no reason to consider this AC Condenser heat concept when the reality is that it would be most efficient as a pre-heater for whatever water heating system is chosen. That’s where the water is coldest and would do the best to cool the AC coil. I feel that this is something that all houses should already be doing to get greater efficiency from their AC and water heating. But we don’t see much (or any) of it. I wonder if that is because DHW demand isn’t high enough to make a difference in AC.
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All this is great for a hobby, but the cost and complexity to get a few extra %, is it worth it. Depending on where you live solar pool collectors could be a good option. That is a fairly low tech option, a rubber mat on the roof
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
yes. I have gone even more low-tech, a black garden hose laying on our blacktop driveway. The solar cover for the pool seems to do a lot preventing evaporation too. The solar cover is not very pretty though, nor is the garden hose in the blacktop driveway, intimately integrating something into the blacktop or brick might be ideal, but won’t provide cooling to the house like something in the roof might. I have read a few horror stories about leaks on the roof causing major problems. But I guess it’s something that would be easy to implement into the garage roof if/when we do it. I’ve considered doing solar there too: the house roof, while a better source for energy doesn’t seem to lend itself well to doing any of this kind of stuff, even a Tesla Solar roof. I’ve looked into it, even paid for the design and quotes. I decided to refurbish the asbestos reinforced cement tile that is on top of original wood shake. That was a big project.
Back on the DHW design. “Thermostatic mixing valve” is the term I was looking for. It clearly can help keep the water from arriving too hot. I bet my storage tank will help mitigate that. But the concept of Legionaires does sound like something I should be thinking about, even with my current setup of a second water heater doing basically nothing most of the time.
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Steep pitches to work on!
When I was small my mother did the black garden hose trick for the kiddie pool.
Some people prefer to keep their dhw at 140f for legionella or other bacteria protection. It also extends the drawdown of the tank.
So you can put a mix valve at the tank and protect the entire system. Or a mixing valve at various fixtures. Most single handle tub shower faucets are scald guard.
If you have hard water there is some maintenance involved with thermostatic valves.
I think 4 states now require mix valves on all DHW sources, even tankless.
These kits make it easy to install thermostatic valves with all the components, checks, unions, temperature gauge, recirc port.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
Thank you. I don’t know exactly how hard our water is, but it is municipal water primarily fed by the Brandywine River downstream of the old mills, and pulled out via raceways that go into the water treatment facilities. Then it’s pumped up into the water towers. I know one of my neighbors had a softener, but I’ve only thought about it. I’ve thought I should at least get myself a filter for the whole house but haven’t gotten into that (or the softener) yet. This project would be a good time to do it. And as with everything else I am planning, give myself a bypass route in the event of issues.
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I'd be reluctant to publicly post easily identifiable pictures of my home's exterior together with my car's license plate. Can't be too careful these days….
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Thank you for the concern. Not my car though.
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I think someone somewhere had said that this is a lot of expense to save just a tiny bit. That might be more correct than I was thinking. I just downloaded the bills for this house for the last two years and see that the peak gas charges are under $400/mo, and in general are no more than $300 more than the minimum. Sure, I might bring the minimum down too, but that's only about $1/day, and the max is only maybe an extra $10/day. The total is under $1700 in natural gas the past 12 months, and under $1950 for the 12 months before that. If the minimum is about $30/mo, or $360/year, then I am looking at reducing a number that might range from $1340 to $1590. Let's call it $1500. Let's say I am in general running at only 67% = 2/3 efficiency, and throwing out 3/10 of the $1500. If that's the case, then at 100% efficiency, I will still need to spend that $360+2/3 of $1500. So, I can bring the $1700 number down to maybe $1200 saving about $500/year. Interesting.
That does help me to realize I should be as efficient as possible with my financial choices. As it sits, I am already looking at more than 4 years before I get my payback on this project. The incremental savings per month are small. So I may just hang the boiler on the wall and have a goal of getting it up and running before the warranty runs out.I will calm down.
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So, maybe I should have done this earlier/before (as everyone said) but it seems I might have an issue with a lack of radiation (to meet the current load of the drafty den addition).
current outdoor temp: 26 FCurrent thermostat setting: 70 F
Current room temp: 62 F
Current Boiler Temp setting: 170 F
Boiler Fires when temp drops to 140 F.
Radiators: ~16 feet of cast iron baseboard radiators.
Boiler firing time t: <2 minutes
Time: 3 am
210k BTU in / 175k out Weil McLain CGa 7
Zone Radiators: 16 feet of cast iron baseboard radiators that are HOT.
Room Size: 20’x18’ (but cold air on literally almost every side, and drafty.Now, maybe this is a bit premature because earlier today the room temp was under 50 F because I have given up on trying to keep this room heated because it is SOOOO DRAFTY. It’s above a crawl space I am looking to get insulated better than it is, and I have done everything I can to block the air that blows into the basement from the crawl space. I figure air-locks would be an improvement, because I don’t think basement air is heating the crawl space. The attic space above the addition is insulated, but could also use some improvement.
But I imagine all the insulation in the world will likely make it only so the room is usable with the current 140-170 F radiators. They are toasty hot right now having run constantly since about 6 PM, that’s 9 hours which did get the room from ~50 F to 62 F. More than a degrees an hour might be ok. I will see tomorrow morning.
What absolutely sucks about this setup is the fact that the boiler only runs for less than two minutes every time it fires. It’s a frigin 210k BTU input 175k BTU output Weil McLain CGa 7 Gold.
I had wired the thermostats so the main first floor zone would always fire when the addition/den fired, but today the first floor was just getting way too hot. So I removed that wiring and setup my wifi thermostat.
I am going to install a modcon, but I am worried this one room / zone is really going to screw up the whole balance of the house. I can get by with temps under 140 for the rest of the house as I proved over the last year with the Den closed off and the boiler set to the minimum temp (condensing bad on cast iron boiler, I know).
So, even though I am going to insulate, I think I need to add some radiation in this room, especially if I want to use condensing temps for my temperature curve. Sure, maybe I could set this zone up with a higher temp, but maybe it’s best just to re-think the radiation of this whole room, and maybe even the other rooms in this porch/addition.
It’s too bad we already refinished the floors.
here’s a video of the room. Not sure I will leave it up too long bc I didn’t inspect it to make sure it doesn’t have personal info in it.
https://youtu.be/IY5hdFW6XGA?si=2XROL97VIcAGFOp2Edit: 3:30 am 63 F (after closing the room off from the rest of the house that is in setback mode right now).
Edit 2:
9:30 am 66 F0 -
You can do some simple math for heat loss in the den. 20 x 18 = 360 sq ft. You say "cold on all sides" and drafty, so the heat loss could easily be 40-50 BTU/hr/sq ft on a design day.
360 sq ft x 40 BTU/hr = 14,400 BTU/hr
360 sq ft x 50 BTU/hr = 18,800 BTU/hr
I don't know size/BTU output of your cast iron baseboard, but let's ballpark 500 BTU/hr/ft.
16 ft x 500 BTU/hr/ft = 8,000 BTU/hr output.
So you see the problem. But with air sealing and insulation, you might be able to get down to 20 BTU/hr/sq ft loss on design day. That would put your heat loss for the room at 7,200 BTU/hr, which your rads might be able to keep up with.
Or you could think outside the box and add supplemental heat like a small direct vent natural gas stove, like a Jotul Lillehammer. I installed one in our enclosed sun porch several years ago, and it makes for nice heat and ambiance in a cold room that had no radiators. We also had a cold floor there but were able to spray foam underneath, which made a big difference.
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The best time and money you can spend would be tightening up the building envelop Those drafts are costing you big heating dollars
Aas @jesmed1 mentioned, it doesn’t seem like 32’ of radiatiors is enough?
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
thank you! I certainly have options. This room is insoortant to me because it is something that I envision as something I could turn into a first floor care suite. There’s a powder room right next to the bar. So it would be easy to convert the bar to a walk in shower in the bathroom. We don’t need that right now. We aren’t even 50 yet and have been very fortunate. My step mother is on her second battle with lung cancer and doing well. But it would be nice to know we could use this room in a pinch. My mother in law is in great shape, but did just bust her face and break her arm falling down the steps at her house. I doubt either would ever consider moving in with us, but sometimes people don’t have a choice. That could be coming soon. You never know. Until then, this room is not important.
I have thought of the wood stove but wonder how high the chimney would have to be. The room is on the right in the pic below.
Space heaters are always simple options though. The ideal solution would be to have enough hydronic emitters to heat the room. I’ve started to think about adding something like warmboard, but that would require all new flooring. I honestly think it might be easier to do the walls or maybe even the ceiling. Maybe antique wall radiators could be a neat addition.
I will see if I can get some curtains hung this weekend. That might help reduce the loss along those double-pane Pella french doors with side lights.
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yes. Totally agree. I’ve had one insulation professional out and am waiting for his proposal. A second comes out Tuesday.
Edit:
On the length of radiators, I believe I’ve got:
5 feet under TV
8 = 4 feet x2 in front of book cases
2 = 1 feet x2 on the side of each book case
5 feet behind the piano (normally have a foam board behind piano to protect it from extreme heat.
Sounds line 20 feet to me. 3 am math isn’t very good, eh.
Right now I have the radiators as exposed as they will ever be for these tests.
The baseboard radiators are 10” tall from the floor and have 1.5” slots at the floor and 1” slots up top to allow air to circulate behind and hit the fins on the back. I have a loose one of these in the garage and might take a picture of the back side if it would be helpful.
The radiators are handling the 26 F ok with 140-170 F and constant flow and the room closed off (to reduce drafts). So I guess I may just have to accept that I may need to be prepared to bump up the target boiler temp when that room really needs heat. I’ve already shown that the most I will possibly save with my new setup will be $500/year. So maybe these scenarios where I feel I need to heat that room will be few and far between and far cheaper to address individually instead of creating massive projects.Insulation it top priority though.
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I don’t think they are legal anymore, but at a previous house of mine, I installed a zero clearance, zero venting natural gas fireplace. Something like that might be ideal to quickly heat that room. I was thinking of a full-blown chimney, but perhaps something that vents through the wall and doesn’t require a chimney would be ideal to put under the TV on the wall next to the house, top right vertical line in the picture of the building sketch below.
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I started looking into the concept of DIY blown-in insulation. It appears anybody can rent this stuff at Home Depot.
https://www.homedepot.com/c/insulation_equipment_rental
So even if none of these pros want to work in my confined spaces, I may still be able to try and DIY the job, both crawl space and attic.
An additional idea I’ve got, probably not very helpful for the bitter cold is adding a heat pump to the basement AC system. The Unico systems in the basement and third floor are now each over 20 years old and using the old R-22. I opened the air handler and it was full of mold I’ve been working on cleaning out. I’m not currently planning on ripping out the working air handler and condenser. But it’s something to consider. This whole project is really getting initiated because I want to open up the basement to have at least one room setup as usable space / rec room. So that least part of the high velocity AC duct work is going to have to be redone. Perhaps I should be considering the idea of adding duct work for a heat pump, assuming a heat pump with high velocity is no good. 2049 Sq ft is the entire area that the current system covers with a 3.5 ton unit (I believe). Here’s the footprint. Portico is not conditioned, and there’s full basement only in the back (top) bump out.
In my old house, we were able to get lines from the 4th floor attic to the first floor ceiling, which I believe was really a better setup on a single zone, but I’ve been told this house is too big, currently with two 3.5 ton units. I guess it’s possible it’s more efficient with two units being about to put the AC where we want it depending on the time of day.
Anyway, I’m in this for the long term, never planning on moving again, never planning on selling. The kids will inherit the house for good or bad. So I am considering everything.
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Radiators like this? If you supply 170, return at 140 the average temperature is 155°, so maybe 400 btu/ foot
You can increase output several ways. Increase the supply temperature, or increase the flowrate which reduces the delta and increases the average water temperature AWT.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
interesting. It might be windier than it was last night, but it’s more than 10 degrees warmer but the temperature in the den dropped from 67 (briefly around 9:45 am) to 65 F, while the rest of the first floor is now 70 F (up from the setback set to 62, but probably never got that cold). This seems to confirm for me that this is probably due to air infiltration. We opened the doors to the den this morning and haven’t been keeping them closed like they were last night. It is possible that the return water temps from the first floor have been cooler, resulting in lower temps flowing through the den. But I guess maybe I can retract my comment about the radiators in the den being able to keep up, at least not at lower and more realistic water temps,
“Shut up and insulate!” Right?I will message the insulation guy that came out this past week. The second guy changed the meeting time to that of my daughter’s swim meet and won’t meet until December 27 otherwise. So I can already tell they aren’t going to act fast for me.
The great thing I believe I have going for me is that it seems this Den addition can be handled separately from the rest of the finished porch area. I’m lucky in that aspect.
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I am glad you brought up flow rate. I believe the Bell & Gosset pump is on 1” pipes, but I noticed that there’s only 3/4” pipes between each of the radiators, and several of them, all piped in series. I’ve insulated the 1” pipes in the crawl space. I think it takes over a half our (or at least 20 minutes) for the return temp to drop to 140 F for the boiler to fire again, but when it does, it’s done in less than 2 minutes. Horrible. Right? Those radiators in that room are HOT! You really can’t leave your hands on them for too long (3 seconds?) before you say “damn!” And pull your hand away shaking it.
But the short cycling sucks. I am hoping that the modcon helps with that. My output will drop from 175k BTU/hr to ~17k BTU/hr, but I am guessing the modcon will have a tighter firing range. So it’s not as if I could expect 10x the firing time. That zone probably does need to be coupled with something else that can increase the overall flow rate. That might be a good reason to add additional radiators.0
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