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Help in Sizing Baseboard and Boiler

Hi everyone...

I'm trying to have Cast-iron baseboard (baseray) install around my house. I need know, how much baseboard I need and what size boiler is good for me.

2nd floor::
- Master room (10ft by 11ft)
- Middle room (10ft by 9 ft)
- corner room (11ft by 9ft)
- Bathroom (5 ft by 8ft)
1st floor::
- Living room (22ft by 12 ft)
- dining room (14ft by 12ft)
- kitchen (not needed)
- small bath (3ft by 8ft)

I'm planning to place a decent wall-hung boiler, 2-zone system with indirect 40 gal tank.
if not wall-hung than regular would do...

it doesn't have to be a combo... separate will work as well... like it is right now.


Re: Help in Sizing Baseboard and Boiler

You need to do a heat loss on the home to determine boiler size and the amount of baseboard you need per room. There are many good sites that can guide you through the process. Google heat loss. Also cast iron base is very expensive.

Re: Help in Sizing Baseboard and Boiler


John is correct---you have to consult the internet by going to Google and entering "heat loss calculation" and select several heat loss calculators in order to calculate the total square footage heat loss of all the rooms, as well as the basement/cellar, etc., a HLC also takes into consideration your geographical location & if you have very cold winters, mild winters, or somewhere in between; also if there is any insulation in the exterior walls (R19 recommended), insulation in the attic (R40 recommended) or if you have drafty windows, or if you have new, tight double pane windows; the HLC also takes into consideration what materials the building is made of, & if the building materials are tight-fitting, or drafty------it's not how much heat the baseboard and boiler can produce to heat the house that matters, it's how much of the produced heat STAYS INSIDE THE BUILDING because of well-insulated walls, attic & windows that makes the house warm & comfortable at low fuel cost.

Thus a typical 2,000 sq.ft. building/heating space in a cold climate can vary greatly in the size of the boiler it needs by assigning anywhere from 25 BTUs of heat/sq.ft up to 70 BTUs of heat/sq.ft as the amount of heat needed to heat the building----25 btu/sq.ft X 2000 =50,000 btu/hr boiler size needed, to 70 btu/sq.ft X 2000= 140,000 btu/hr boiler size needed (that's a BIG boiler that burns a LOT of fuel)------that's why it's so EASY to make a big mistake & put in a boiler that's way too big (and burns way too much fuel) or too small, unless you consult with several local heating contractors (Yellow Pages: Heating Contractors) to get an accurate calculation of the size boiler you need.

The same goes for the amount of baseboard you will need for each room---it has to first be determined how much heat in BTUs/hour are exiting (quickly escaping unseen right through the walls & windows) the building on a cold day (if you have well-insulated windows, walls & attic the heat STAYS INSIDE the living space much longer, instead of quickly exiting to the outside via the poorly insulated windows, ceilings & walls), depending on the amount of wall insulation, attic insulation & windows condition, & your local climate, & how tightly the building is constructed.

If you try to size the boiler on the size of the existing one you have now, or without doing a HLC, or by not consulting with local heating contractors, you will no doubt make a big mistake & install something that is too big & burns an excessive amount of fuel & wastes heat & money.

In regards to the baseboard calculations, John is right, Burnham cast iron Baseray baseboard is very expensive (approx $40 to $50/linear ft) & takes special tools to properly install the product---in many cases it is not necessary to install a full room with Baseray, perhaps limiting it to the largest room (most frequently used) or most difficult room to heat & then at only 40% of the total baseboard footage, the rest can be installed with standard HW baseboard ($6/$7 linear ft) at a much less expensive cost.

The Baseray cast iron rads DO have the quality of staying hot a lot longer (up to an hour or so) after the heat goes down, where standard baseboard quickly loses its heat once the t-stat is satisfied & the boiler shuts off.

I think you would be better off concentrating your money expenditures on upgrading the blown-in insulation in the building's exterior walls & attic (consult Yellow Pages, under "Insulation" for one-day blown-in insulation services for exterior walls & attic), as well as replacing any single-pane windows with 2-pane vinyls (this is known as "tightening up the house envelope")----these measures will pay big dividends in saving on your heating bills, as well as your summer cooling bills, and you can avoid the high cost of installing Baseray in every square foot of rooms you have, which I think is unnecessary.

Re: Help in Sizing Baseboard and Boiler

Thanks. I was issues because I'm getting major difference in numbers from different calculators.

I live in NJ...

But thanks all.

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