Hot water with cast iron radiators

Russ_2

Thanks for the replies. Jim you kill me..LOL.

"This makes absolutely no sense. The boiler has no feelings of the kind you describe. It just makes heat. "

My concern was whether the boiler can keep up with such a large amount of return. I dont think this is the original boiler, and I do believe the piping is original. The boiler is very small, The cycle down times are very short. It seems to run all the time. I am talking about capacity vs load.

The old folks who lived here had nothing. They had linoleum on the floors and it was so worn in the kitchen, they painted over the pattern. There were newspapers under the linoleum from the 50's. So I wouldnt doubt it if they undersized because of cost. Tonight, I will get the dope off the boiler and report back. All I know at this time is that it was a montgomery wards model.

Also, it isnt my intention to remove the radiators. They have alot more heating capacity than a single line through a baseboard. If I were to find that there arent enough for the size house to increase my efficiency, I would install more , such as a kickspace heater in the kitchen. Thanks again guys. Russ.

Russ_2

HW Boiler w/ cast Iron Radiators

Lets face it, it's old. Massive consumption of fuel, pretty good heat. I have used 1/4 tank (275) in less than 10 days. The system is two pipe with a 2" parallel setup in the basement. Each radiator is fed from the 2" by a pair of 1/2 to 3/4 lines. My contention is that the amount of cold water being returned to the boiler by the circulator on the return side is overwhelming the boiler. The efficiency of the boiler was written on a service tag years ago at 75%. So here is the deal...

In replacing the boiler, I know how to configure the BTU requirements of the house. How do I figure out the BTU output of the existing radiators, vs replacing them all with baseboard finned radiation. Are there plus's to keeping the cast iron besides the residual heat output vs baseboard?

Should I replumb the house or is this a good configuration? 2' seems awful large . The house is about 2k sf.

Thanks in advance. Russ.

Jim_65

Heat Loss/EDR

On this site there is a link to Slant/Fin's heat loss calculator that you can do a room by room heat loss of the structure.

Also on this site Dan H. offers a EDR "Every Darn Radiator" book that you can take your existing radiators and calculate the EDR (Equivalent Direct Radiation) on and compare to your heat loss.

IMHO it makes me absolutely cringe when I go to a site visit or initial phone call and people want to switch from CI Rads to HW Baseboard. I would rather have folks entertain the idea of European style Panel Radiators.

I actually have a customer right now that is cussing the previous homeowner's for making this choice. It not only has created problems in distribution and system balance but they are not the most esthetically thing to look at everyday. IMHO I like the comfort from Radiators compared to convective type of heat emitters.

Good Luck!

Jim Hoffmann

> My contention is that the amount of

> cold water being returned to the boiler by the

> circulator on the return side is overwhelming the

> boiler.


This makes absolutely no sense. The boiler has no feelings of the kind you describe. It just makes heat.

Also, the only reason to replace radiators with baseboard is if you're moving out and want to screw the new occupants.

jeff_51

i'll give you odds

that those rads are so oversized you can run at 140-150 degress and that means a condensing boiler would be perfect especialy with an outdoor reset. Oil or gas?

Dan_15

please do not rape your home of those wonderful CI rads. I am another HO cussing the previous owner for doing the same. I replaced the old pot-belly beast with a high efficiency constant circulation system, and let me tell you if I still had those CI rads I could probably get my fuel down to 600 gallons annually.

Constantin

Here's what I would do:

Your present heat emitters may very well be perfect to ensure comfortable and economical heat as long as you address all the other issues that face your home. I would not pull out the radiators or the distribution piping and would focus on the causes of your discomfort, not the symptoms.

Before you do anything else, I would contact energystar.gov to have a local energy company consultancy come out and evaluate your home. Ideally, they'll bring a blower door and other testing equipment, followed by detailed recommendations. I'll bet that replacing the storm windows (Harvey Tru-Channel) and retrofitting cellulose insulation or foam into the walls (if there is no knob & tube wiring in there) will yield immediate returns. I would also pay very close attention to the insulation in the basement and the attic.

Once you are done reducing your energy losses, you can set about maximizing the efficiency of the heating plant in your home. If the chimney is not lined, this is the time to do it, followed by a boiler that can handle low return temperatures. Since your heat losses will be a lot lower once the home is insulated, you can expect a relatively small boiler to do the job of its much larger predecessor with aplomb. Installing a smaller boiler is not only more efficient, it also ought to be cheaper. Thus, while the insulation/weatherization package adds some cost, it also reduces intial costs elsewhere.

Since the present boiler is working, I'd start by finding a great contractor to work with and to leverage the resources at energystar.gov to your advantage. Then map out an approach that suits your time horizon and wallet.

Jim Hoffmann_2

> My concern was whether the

> boiler can keep up with such a large amount of

> return. I dont think this is the original boiler,

> and I do believe the piping is original. The

> boiler is very small, The cycle down times are

> very short. It seems to run all the time. I am

> talking about capacity vs load.


Again, this makes no sense. The load has nothing to do with the "amount of cold water", as I said earlier.

If it is heating the house, the boiler has enough capacity. Boilers are most efficient when used at close to 100% capacity.

You can heat houses with lots of water circulation, or with little. Some houses are heated with relatively cool water, others need warmer water. Efficiency does NOT depend on whether there is too much water circulation.

It seems you are trying to solve a problem that doesn't exist. You may want to do some homework on hydronic heating before making changes based on unreliable gut feelings.