Baseboard formula?

[WorldBuilder]

Hi all,

I have heard that there is a formula for calculating how much baseboard is necessary for a forced hot water heating system. Something about "650 times the amount of baseboard."

Basically, say I had NO heat system, and was doing one from scratch. Can someone answer me these?

How do I calculate how much baseboard is needed in a room? And, why?

Once I have that number, how do I calculate what size output boiler I need?

I'd appreciate it, thanks!

Chris

[DavidJ]

You will need to do a heat loss calculation for your home. This includes calcualting square footage of outside walls, window and door areas and types, insulation, and the general tightness of the house. Older houses tend to be leakier than newer ones. This information establishes the amount of BTU's the house is looseing on a design day. The boiler needs to be sized to match your heat loss. The boiler will need to produce 'X' BTU's to keep the house at 70 degrees when it is 'Y' degrees outside. Design day conditions are much different in San Diego than Boston. Your local planning/permit office probabaly has a spreadsheet or at least a set of tables that will allow you to make you heat loss calculations and size your boiler.

However, once you complete it I would certainly have it reviewed by a heating professional before you finalize your decision on boiler type and size. Once you have the boiler sized you can use your heat loss calculations to determine the BTU's required by each room and then determine the number and size of heating units you need to install.

I can't emphasize how important it is to plan your system correctly at this stage. Effective planning now will result in efficient boiler operation (and comfort) down the road.

Good luck with your project.

DavidJ

[WorldBuilder]

Thanks for the info. Actually, this was all hypothetical because the house already has a system, but I need some repairs. I asked hypothetically because I don't have time to be typing a 3 hour story on the forum, LOL.

The house is an old 1910, but I've rebuilt damn near everything, and it's pretty well-insulated now.

Basically, I just want to know some basic calculations.

What's the math?

Chris

[Ed Imeduc]

Go to http://trainingroom.slantfin.com

Or http://www.slantfin.com

Should give you all you want to know.On hot water


ED ;)

[WorldBuilder]

Ed,

Thanks, but I wasn't able to find anything. Any other thoughts, guys?

Chris

[arkayassoc]

Basically, I just want to know some basic calculations.

What's the math?

Chris

Chris,

What amount of BTU's/Hr do you need? Everything is based off of that, and your circulator flow rate.

For example, a Fine/Line 30 will give you 580 Btuh/ft at 180°F. At lower temperatures, the output is lower (Ex.: 380 Btuh/ft at 150°F.). Also, at a load of 21,000 (or so) Btuh, the system flow rate is only 2.1 gallons per minute at a 20°F. drop.

I think you are trying to take a shortcut here, and I don't think it will work. You need to know heat loss for your home's construction, insulation, etc, and the area that you live in, and then factor in the output temperature of your boiler, and the flow rate, before you can determine how much baseboard heating surface you need.

There are programs out on the web that will help you determine what your heat load is. But I don't know of any shortcuts.

[WorldBuilder]

I'm not looking for shortcuts, but I see what you're saying.

I just heard that basically you have to size your rooms and get baseboard, then size a boiler depending on that. Guess I was wrong. Thanks, guys!

Chris