Heat Loss Calculator

Needy

I am going to replace my old oil boiler for a natural gas one. It seems like most of the HVAC people want to match, or increase, the BTU's of what I have. I do not think that should be the approach, so I want to do my homework, to see if what I have is realistic.



Some ask if the house heats up ok, and I am not sure that is logical question, or thought, as, I would think, any house would heat up ok if it were using a boiler that was twice the size it should be, for the house. Maybe I am wrong about that. Anyways, the previous owners took radiators out of about 600 square feet of the house, and replaced with electric baseboard. I am not sure if this was factored into the existing boiler, or not. I do want to put the radiators back. in.



I know about the heat loss calculator, but I have enough gray hairs, as it is, and I want to keep all that I have...PLEASE, is there anyone out there that can simplify this a bit. I found a simplified calculator, it basically told me to take the cubic feet in the room, and multiply it by 4 which was the factor for poor insulation. I did this room by room, added everything up, and the number I got was 69,740 BTUs. My existing boiler is 144,300 BTUs. I know this does not take into consideration window area and exterior door areas, and I am sure other stuff too. I am wondering how to factor that stuff into the equation.



I live in Delaware, and I have radiator heat, the old fashion floor models. This is a hot water system. The house is 1900 circa. There are 48 windows and 4 exterior doors. The house sits on a brick foundation, there are 7 small basement windows, the basement has a concrete floor under the main sections of the house, and a 4' dirt "crawl space" that runs about 10' x 60' under some one story bump outs. There is a walk up attic, the roof is new, and I have a high profile ridge vent plus all the necessary soffit vents. I think the insulation to be original in most the house, hence the reason for using the 4 insulation factor. I have only updated the insulation in the one story bump outs, but I still did my calculations with the 4 factor, for those areas. About half the windows are new, but that means, installed by the previous owners 20 plus years ago, they are wood clad and double pain, but certainly not the energy efficient windows, of today. The other half has the original, wood windows, with aluminum storm windows. The exterior doors are all new, within the last 4 years. The total square footage is 2200.



Any help in sizing the boiler would be greatly appreciated...Thanks