Cast iron baseboard for new construction??

[Chicagoan]

I'm in the process of making basic choices, including HVAC, for a new home I'm having built. I've had hot water heat with cast iron baseboard my entire life - growing up and now in my current home (35+ years, 1950's tract house). When I finished my basement 30 years ago, I installed the same cast iron baseboard that was in the house on the main floor (Weil-McLain Snug Baseboard).

So now comes the new home. Is cast iron baseboard installed anymore in a new home? Would I be insane to request it? I like it so much in my current home, I'd hate to lose it when I move. I see that Weil-McLain still makes cast iron baseboard as do some other brands based on google searches. It sort of gets me that cookie cutter tract homes from 60 years ago had it standard while newer, very expensive homes have aluminum fin baseboard if they even have hot water heat to begin with.

What I don't like about aluminum fin baseboard (based on experience/claims of friends and family):
1. Noisy (popping and creaking when heating up and cooling down)
2. Easier to damage when bumped by furniture.
3. Pain to clean the fins.
4. Dries out the air more than cast iron baseboard (??)
5. Larger temp swings compared to cast iron baseboard (??)

Is hot water heat coupled with cast iron baseboard really better (or is it just my imagination)? Would I be better off going for in floor radiant heat? I'd appreciate any opinions, suggestions & guidance.

 

[Jadnashua]

CI has a much higher thermal mass, so it heats up and cools off slower, overshoot can be an issue if the thermostat isn't smart enough as it will continue to radiate heat after the pump is shut off much longer than aluminum fin stuff. CI costs more to buy, but it is nice.

Nicer, though, is a properly designed radiant flooring system. There's no issue with furniture placement blocking the radiator, and a warm floor really is nice. The room temperature tends to be more even, too. Both CI and a properly designed radiant floor system can use a lower water temperature and provide the necessary heat. The finned stuff tends to not work all that well unless the temperature is higher so you get convective heating verses the radiant you get from the CI or radiant floor. With a modern condensing boiler, being able to use lower temperatures means the system would be in condensing mode more often, and if it's sized properly, may run continuously more often...a constant heat is more comfortable than swings up and down. A radiant floor system tends to have more even temperatures vertically, too, so your feet aren't cold while your head is hot. Running around in your socks is comfortable and if you have pets, they'll love it!

I think radiant is more common elsewhere is that if you also want a/c, having ducts and a boiler with radiant means two systems that can't share parts...i.e., more expensive. Many areas in the USA really want their a/c, and some are just uncomfortable without it. We're spoiled, and our energy costs tend to be cheaper than many other places in the world. I have radiant in most areas, and like it. If I were to build a new house, I'd also install it there.

 

[Sponsor]

 

[NY_Rob]

To each his own...

I personally love cast iron baseboard.
I replaced 18' of fin-tube with 19' of CI BB in a "problem" zone in my house. The "problem" was that particular area was built as a stand-alone mother/daughter apartment and was only attached to the main house on one side- the other three sides are exposed to the weather. That area always cooled off faster then the main house, so I saw more cycling on the boiler just for that one zone.
Over the summer I pulled the fin-tube and replaced it with 19' of cast iron baseboard (Burnham BaseRay).
Now that the cold weather is here, I'm happy to report that the CI BB has completely ended the cycling problem there- it's slow to heat and even slower to cool off. The room is now wonderfully warm with even heat vs. the roller coaster up/down temp swings we had with the no-mas fin-tube.

If I was building a new home- I would 100% go with a mod-con boiler and cast iron baseboard all around.

FWIW- The mod-con boiler works great with cast iron rads... 120F supply water, really long burn times, no short cycling. Super efficient low temp system.

 

[Dana]

Unlike fin-tube convecting cast iron baseboard are RADIATORS, and you can FEEL the difference! Fin tube baseboard has very little radiant output, and are almost exclusively convectors, heating the air rather than radiating heat directly to the objects & occupants in a room.

But European style low-temp thin profile steel flat panel convecting radiators are real radiation too, cheaper, and at least as comfortable as cast iron baseboard rads.

Bi-metal & aluminum convecting radiators popular in Asia and parts of Europe are faster reacting due to the lower thermal mass (lower water volume), but are also excellent radiation from a comfort and efficiency point of view:

To get the maximal comfort & efficiency out of radiation (cast iron baseboard or other) is to use an "outdoor reset" approach to the water temperature, so that the radiator is always at just the right temperature to keep the room at temperature and not cycling the temperature up /down by very much. With the water temperature tuned to respond to the outdoor temperature, the radiators are always radiating, rather than delivering a hot-flash followed by a chill.

 

[DewPoint]

You’re not insane for wanting it. I think your biggest challenges will be budget, especially if you’ll want A/C, followed by finding a good designer/installer, followed by convincing others that you’re not insane.

If you go for it, take time vetting the designer and installer. Don’t settle on someone who says they can do it; get someone who actually does it successfully. I look forward to hearing more about your new system as you get started and congrats on building a new home.

 

[Dana]

If you want to do this right, keep track of the room-by-room heat load calculations as the particulars of the design features of the house evolve. Then specify sufficient radiation to be able to cover the design day load at an average water temperature of 140F or lower. Sometimes there isn't enough running wall length on the exterior walls to deliver that with 9" cast iron baseboard, but it's fine (if less traditional) to use interior walls too.

 

[NY_Rob]

^ good point about the budget DewPiont.

For reference a 6' section of Burnham BaseRay case iron baseboard ran me $188.
The whole 19' replacement came in at $720 for just parts by the time I added in end caps, tie-bolts, corner compression fitting, etc...

A 6' section of fin-tube is about $60 at your local big box store... about 1/3 the cost of the CI BB.

 

[NY_Rob]

Unlike fin-tube convecting cast iron baseboard are RADIATORS, and you can FEEL the difference!
Fin tube baseboard has very little radiant output, and are almost exclusively convectors, heating the air rather than radiating heat directly to the objects & occupants in a room.

Thank you for posting the above Dana!

I have tried to explain the different "feel" in the area where I swapped out the fin-tube for cast iron baseboard. I've been struggling how to describe it, I've referred to it as "old school warm", etc... but with your much more technical explanation I know know exactly why it's the nicest "feeling" room in the house now!
You literally just feel better/cozy in that room now!

 

[Dana]

You definitely feel cozier in a room with real radiation.

Buying Burnham or Weil-McLain cast iron baseboard new it's tough to get the materials cost very much under ~$40/foot, Asian knockoffs maybe $30/ft. In my area there are scrap yards that will sell you a mile of used c.i. baseboard at $15-20/foot, sometimes less.

19'-20' of 9-10" cast iron is rated ~10,000 BTU/hr @ 180F AWT, for $750-$800 material cost.

A premium-brand flat panel rad with that much output runs ~$500-550.

A decent middle of the road Myson that delivers ~10KBU would be under $400, as would aluminum or bimetal convecting rads.

Flat panel radiators are definitely less expensive than new c.i. baseboard, and sometimes even competitive with used c.i.

Most of the thermal mass in a cast-iron baseboard is the ~2.5lbs of water per running foot, not the iron itself. Steel flat panel radiators typically have more thermal mass per rated BTU than cast iron baseboard, aluminium convecting rads usually less.

For guesstimating how much c.i. baseboard it takes to deliver a room's design heat load at 140F AWT assume ~300-325 BTU/hr per running foot. So a bedroom with a design heat load of say 2500 BTU/hr with 140F would need a minimum of 2500/300= ~8', which isn't too tough to manage, whereas a great room with tall windows and a design heat load of 11,000 BTU/hr would need 11,000/300= ~37', and may not have enough running exterior wall length to get there, but a flat-panel rad solution would fit. (A pair of ~20" tall x 7' wide Myson T621-5-20s can deliver that much, for under $700.)

 

[NY_Rob]

The panel rads you listed above, are they simple series loop like fin-tube and CI BB or do they use monoflow/diverter Tees?

 

[Jadnashua]

Now, rather than a section of radiators on the wall...picture the entire floor doing the same thing and you’ll see my point. Radiation verses convection will be more comfortable however you do it. It can also be done in the walls and ceilings if that might work out better.

 

[Dana]

Euro-style panel rads tend to have their own tunable internal bypass branches and an adjustment knob on the side for tweaking the radiator flows (there are thermostatic valve/knobs too) and get plumbed in series, without monoflow tees. The number of panel rads that can be plumbed in series is sometimes limited though (three is a typical number, but consult the manufacturer's literature.)

Radiant floors are DRAMATICALLY more expensive than panel rads or c.i. baseboard. They're nice (for sure!), particularly with rooms with lots of window area that need an uptick in mean-radiant-temperature, but we're talking apples and custom-designer pears here.

 

[Chicagoan]

Thank you everyone for your responses. It's good to know I'm not crazy (at least with this).

The basic lesson is go for radiation as opposed to convection, and there are a few ways of doing that. If my new home were being built in the Chicago area, I'd have tons of options. As it is, I'm building in a rural area of Michigan's Upper Peninsula and options are more limited. Hot water heat, even in new construction, is pretty common there (unlike Chicago) but it's mostly fin tube or in-floor. I will not have AC - not needed.

Perhaps I'll start out by requesting in-floor. I didn't realize though that it's way more expensive. The other drawback with in-floor is I want wood floors in some parts of the house. As I understand, in-floor would require engineered hardwood which is rated for an install over in-floor heat; it's also more expensive than just plain old site-finished oak flooring.

The steel radiators are another option, but I'd have to get used to the look. To me they look more clunky although that's what most people say about cast iron baseboard. It seems to me that stretching out a cast iron baseboard along the outside wall gets you more radiation at every point in the room plus there's the small amount of convection directly under the windows unlike a steel slab radiator which is more like the old large cast iron radiators that are off to a side.

Well, I'll keep you all posted with what I finally end up with. I really don't want to compromise with this especially in a colder climate. Besides, I think I'm compromising enough by giving up electric conduit and plaster walls & ceilings.

 

[Dana]

Standard hardwood floors work fine with radiant- don't sweat that one. The key to getting radiant floors to work really at design temp in a location as cool as da Yoop is to keep the design heat load of rooms heated with radiant floor bounded. That means not going crazy with window sizes, and using better than code windows. Triple panes are expensive, but a huge comfort factor when it's in negative double-digits outside, raising the mean radiant temperature of the room, and allowing the surface temperature of the floor to say in the "comfy-cozy" range rather than "sweaty roasting feet on a hot bed of coals" range. As long as the 99% design heat load is no more than 25 BTU/hr per square foot of available radiant floor it's pretty straightforward and comfortable. Sometimes it makes sense to use a combination of radiant floor and baseboard or flat-panel.

When the house is still in the design phase you have a lot of control over the room loads, and between better windows and better than code wall-R you can bring the BTU per square foot of radiant floor into the comfortable zone fairly readily. Doing it as an afterthought or retrofit is more difficult and more expensive.

With decent windows (~U0.25 or less) there isn't nearly as much advantage to putting radiation directly under the windows as there was when it was leaky single-panes that people kept cracked open overnight so as not to die of carbon monoxide poisoning from their coal burning boilers. A panel rad just about anywhere on or near the exterior wall feels pretty much the same. Even if you cheap out with IRC 2015 code-max U0.32 windows it's still not as big a deal to put the radiation elsewhere.

 

[NY_Rob]

I can see a big advantage in using panel rads in rooms with limited wall length like a tiled bathroom, etc... where most of the wall space is occupied by a shower/tub, vanity, toilet, linen closet, entry door, etc...
In our upstairs bathroom for example, we literally only have 4' of wall for a radiator because of the bathtub and vanity. At 140F AWT 4' stick of fin-tube only gives you 1280BTU's where a 4' Myson panel rad could put out over 5,000 BTU's!


Thanks again for the info and followup on the panel rads Dana!
The upstairs bathroom I mentioned above is the last stop of five rooms on our upstairs loop and only gets 100F AWT when my SWT is 115F .
It may be a prime candidate for a panel rad since we have plenty of height available (up to the bottom of the window) just not much length because of the tub and vanity.

 

[Dana]

For bathrooms heated towel rack rads (or a towel-rack + baseboard) are a really nice solution if you have the wall area for it. A panel rad may be overkill-have you run the actual load calculations on that bathroom? Unless there are large and lousy windows in the bathroom and the bathroom is on corner with two or more exterior walls, the odds are the heat load will be under 1500 BTU/hr even @ -15F.

I'm in zone 5A, in a 2x4 framed 1920s house. The worst-case bathroom is an upstairs dormered bathroom with R19 in the cathedralized ceiling and R13 cellulose in the walls one of which is completely exterior, with two others being roughly 1/2 exterior (the intersection of a sloped roof), which comes in at about 1100 BTU/hr @ +5F (the local 99% design temp) in a Manual-J. It's currently comfortably heated (even though it's under-radiated), with a 42" stub of ~10" cast iron baseboard (Weil McLain Snug) at an AWT of ~125F, good for about 800-850 BTU/hr. With one warm human and the lights on it has no problem keeping up even into negative single digits. If there were sufficient wall area for a heated towel rack I might have gone that route, or put it in series with the iron baseboard, but the sloping roof makes for very minimal amount of area. Almost any panel rad would have been overkill.

The 42" c.i. baseboard is one of two radiators on that micro-zone, the other being a ~58" wide SunRad cut into the kneewall heating the adjacent large guest bed room.

 

[NY_Rob]

^ You're probably close on the 1.5K BTU heatloss for that 8'x8' bathroom... it's floor and all 4 wall tiled right up to the ceiling, with 1.5 exposed walls so once cold.. it takes a while to heat up with all that ceramic tile. But, I'm struggling to get even 1.5K BTU's out of my 4' of Heating Edge 2 with low 100F AWT.

Looks like the HE2 puts out 205BTU/ft at 100F AWT, so I'm only getting 820BTU's out of my 4' stick. I guess that's why that bathroom is always 1 or 2 deg colder than the other rooms even with the heat on. Back in the day that 4' of std fin-tube got 180F water from the old boiler (it was the first room in the loop back then) so it was putting out over 2K BTU's vs. 820BTU's now.

If I oversize a panel rad, it seems like I can adjust the bypass/flow if it puts out too much... which at 100F AWT seems doubtful.

 

[Jadnashua]

IT takes more labor to wind pex into place, but materials wise, it's probably cheaper. Depends on the subfloor and overall design. The Romans used radiant floor heating, so the concept is not new...but, burning fires beneath the floor isn't good for CO or smoke if there's a leak!

Schluter has a system, Bekotec, that gives things a lot of thermal mass and makes placing the tubing easier.

https://www.schluter.com/schluter-us/en_US/Modular-Screed-Systems/Schluter®-BEKOTEC/p/BEKOTEC

you could tile over it or put down an engineered wood floor. That overall cost would be higher, but there are other methods. If you are going to embed the pex, you need to consider that in the overall design, as floor/ceiling heights, door openings, etc. all need to align for a harmonious end result.

If I were going to build a house today, I'd seriously consider ICF or SIP construction all the way up. Essentially, a monolithic wall (and potentially roof with a SIP) so no infiltration, high insulation factor, and with ICF, a huge thermal mass to help moderate temperature swings. My sister took a class at the community college where they introduced that...a public school out (I think) Wisconsin built a new gymnasium with the stuff...cost them $100/year to heat it! An average of 3-days for the temperature swings to affect the insides, so unless it was a protracted cold spell, the thermal mass kept things comfortable. You probably wouldn't want to try an extended setback, as it would take a long time to recover, but doesn't cost much to maintain. Almost no sound propagation through the walls, either, but noise may not be an issue where you live. It sure does get cold on the UP though, and windy.

 

[Dana]

NY_Rob: At an AWT of 100F a panel radiator of any height puts out about between 1/5 and 1/4 of it's rating at 180F. So if you're just getting rid of the HE2 and replacing it to cover a 1500 BTU/hr load you're looking for something rated at least 4 x 1500BTU/hr = 6000BTU/hr @ 180F AWT, but doesn't need to be more than 5 x 1500 BTU/hr = 7500 BTU/hr @ 180F.

Something like a ~2' tall x ~40" wide Ecostyle B-24.40 would do it, or a ~3' tall x ~32" wide B-36.32 would more than cover it.

For less money a ~2' tall x ~48" Myson T6 IVC T621-6-12 or 2' tall x ~36" wide T622-6-92 would also do it.

There are others.

 

[NY_Rob]

Thanks Dana,

I was considering the 36" wide model as I don't want a tight fit on both sides... I'll have to look into it's additional depth.

Sorry to the OP for kind of hijacking this thread.