Is there any downside to cast iron radiators?

[Singed Eyebrows]

Don't pass up some nice smaller rads because you are looking for 10 to 15 footers, Randy

My current thinking is 2 long shorties in the 2 spaces that make up the majority of the house and then a few small ones for the rest of the house zoned separately.

Zone 1 is the main floor living space is 1300 sq ft, 10 ft ceilings and about 400 sq ft of glass. The glass is all on one 55' wall that faces S/SW. This space gets a long shorty roughly centered on the 55' wall.

Zone 2 is the lower 1100 sq ft walkout level below zone 1 with another 50' of glass. This space will house the boiler/storage. Another long shorty will be centered on this wall of glass.

Zone 3 will be 3 bedrooms and bath on the main floor. 4 small rads.

Zone 4 will be a bedroom and bath on the lower level. 2 small rads.

Zone 5 dhw. Superstor or similar.

Then leave expansion stubs for shop, garage, etc. Maybe 3 or 4 more zones.

It is a lot more complicated than my BILs system but offers a lot more control which should mean a lot less babysitting and temperature swings. Seem right?

I don't really have the expertise to answer that. My experience is that CI rads seem to heat a lot more than their BTU ratings. Also rads that are too cold aren't going to be much of a "radiator", Randy

 

[karri0n]

Don't pass up some nice smaller rads because you are looking for 10 to 15 footers, Randy

My current thinking is 2 long shorties in the 2 spaces that make up the majority of the house and then a few small ones for the rest of the house zoned separately.

Zone 1 is the main floor living space is 1300 sq ft, 10 ft ceilings and about 400 sq ft of glass. The glass is all on one 55' wall that faces S/SW. This space gets a long shorty roughly centered on the 55' wall.

Zone 2 is the lower 1100 sq ft walkout level below zone 1 with another 50' of glass. This space will house the boiler/storage. Another long shorty will be centered on this wall of glass.

Zone 3 will be 3 bedrooms and bath on the main floor. 4 small rads.

Zone 4 will be a bedroom and bath on the lower level. 2 small rads.

Zone 5 dhw. Superstor or similar.

Then leave expansion stubs for shop, garage, etc. Maybe 3 or 4 more zones.

It is a lot more complicated than my BILs system but offers a lot more control which should mean a lot less babysitting and temperature swings. Seem right?

Seems really complex, possibly unnecessarily so. CI rads hold heat for a while, but they aren't going to still be heating you out of the room hours after the circ stops cycling. It's a matter of lowering the thermo by 2-5 degrees if you are anticipating that they are going to continue heating far past the temp you set them to.

 

[Singed Eyebrows]

They shouldn't overshoot much with a Flo Chek on the line. At least mine didn't with the gas boiler. I didn't put one in with my Atmos & I'm being cooked out. A Taco EBV should also take care of overshoot & thats what I'm going to install next as I need the unrestricted flow for gravity feed, Randy

 

[Singed Eyebrows]

I was assuming storage & this might not be correct. Obviously you can't just shut off flow to the heat sink with a solid fuel boiler, Randy

 

[SolarAndWood]

Definitely doing storage and also very much into non-uniform, heavy things that are designed to last indefinitely. We'll see how the cast iron and propane tank scrounging goes.

 

[Singed Eyebrows]

S&W; Run a 2 pipe system, all the inlets on one & outlets on the other. Pitch everything upward & you won't trap air. A heating contractor came over many years ago & gave this advice & this has worked well ever since, Randy

 

[SolarAndWood]

Run a 2 pipe system, all the inlets on one & outlets on the other.

Parallel as opposed to series? I have very few rooms in the house with very different solar gain. That is kind of why I am thinking that I need 4 zones + dhw to maintain control. The 2 big shorties, maybe a half dozen smaller units and I think I am done. I am toying of the idea of not even using a radiator at all on the lower walkout level and just coming up with a way of exposing some of the propane storage tank(s) to heat the space.

 

[Singed Eyebrows]

Thats what works for me. I was going to suggest a bunch of zones & you have that handled already. I'd be surprised if series(inlet to outlet,outlet to inlet) would work well. With parallel you can adjust heat with a valve(on rad) or use a thermostatic valve(no electricity) etc. I have found nice rads at the scrap yard. I once got a 400 pounder for $19.00. I don't think I ever heard anybody say they made a mistake putting in CI rads. I can't say the same about a number of people that took out CI rads for baseboard, Randy

 

[DBoon]

Cast iron radiators are the most nearly perfect form of heating. I'd love to combine mine with a wood boiler someday. If you buy them new or used, just make sure to size them all correctly for a room and/or get some adjustment valves on each one. I wouldn't plumb them in series - I have a parallel arrangement and I can't imagine how long it would take for the last cast iron radiator in a series arrangement to get warm - maybe never.

You'll find that you don't need to set the thermostat as high as with baseboard radiators since they are radiating heat for a long time to the room. This radiant heat will make you feel warmer than you otherwise would.

Only drawback is size (they do limit furniture placement) and some people find them ugly. I don't feel this way at all about them. I've looked at buying more than one house over the years where the owner was so proud to have replaced all the "ugly old" cast iron radiators with (ugly, new) baseboard radiators. People who visit (when I am running the oil heat and not the woodstove) naturally gravitate to them and sit on them like furniture.

 

[Eric Johnson]

Like you, I think they're beautiful. I have one in my greenhouse with a lion image cast into it. Here's a couple of pics. You can see that in this instance, I violated the "don't mix 'em" rule. The baseboard is pretty worthless. What I need in there are more ci rads!