duncanheat wrote:can a person add up the radiators to get the btu requirement of a boiler needed?
duncanheat wrote:I had a heat guy come in to size my oil boiler before we put it in and he went around adding up the "cores" of the radiators. He said we can size the furnace to the size of the total heat that the radiators would supply. He came up with roughly 183,000btu, so we went with a peerless oil boiler wv-05 200 with a 1.75 nozzle(~186,000). The oil boiler does fine we use roughly 1400-1500 heating the house for the year and also we have an AERO oil hot water tank that burns in the summer. It seems now that I have a collection of efficient running oil burners that were fine when oil was $1.80 but not now. I just didn't know if changing to a continous burn hard coal boiler would I still need roughly 186,000btu or more or less. I would like to get a "Keystoker" because of the local dealer is right up the road but I saw on the Harman website the VF3000 will heat a 3000+ sq. ft. home with only 95,000btus???
Assuming your existing boiler and radiators provide the level of heating comfort you need you can use them to size a replacement boiler or an additional coal boiler. Use with caution. As stoker-man points out what you have is likely oversized. Largely because of the "rule of thumb" design rules used by plumbers and heating contractors years ago. They are over conservative guidelines. The contractor didn't want something that didn't work. Today with computers providing the computational power a much more accurate heat loss computation is easily done. You should do a "Manual J" calculation on your home. It's a room by room analysis of your heat loss (heating BTU) and cooling load (A/C BTU). It considers all the construction aspects of each room, insulation, windows, doors, adjacent rooms, etc. Totaling the room heat losses gives you the total BTU requirement. Do not oversize your coal boiler, it leads to inefficient, i.e. uneconomical operation. Since you have an existing oil boiler a good design approach would be to design for the average outside cold winter temperature. Then when the rare extra cold day comes along your oil boiler can make up the difference. Having a smaller coal boiler is also important if you plan to heat your domestic hot water with it in summer time. You can do this with your AERO hot water heater by plumbing it as another heating zone. In my opinion indirect how water heaters are more efficient that in boiler domestic water coils. It makes year round coal heating of hot water practical especially in a centrally A/C house.stoker-man wrote:duncanheat wrote:can a person add up the radiators to get the btu requirement of a boiler needed?
Yes, you can add up the radiators and determine the original BTU output sizing for your house, but most likely, extra radiation beyond need, was installed when the house was built.
Over radiation results in shorter runs of the stoker to fully heat the house, which is not as desired as proper burn time, but much better than being under radiated. Most likely you have plenty of radiation.
I'm still searching for my radiator sheets.
Given the likely oversizing of your initial radiators I think a 192,000 gross and 163,000 net boiler is too large. Look for something less than 144,000 BTUs.duncanheat wrote:I've done the radiator evaluation and it comes up to around 144,000 BTUs. I believe a stoker with a BTU supply of around 170,000 would work. I think Keystoker makes a model KB-8 (192,000 gross and 163,000 net). Now I need to see how much one cost and where to get one.
lincolnmania wrote:i cant speak for the efm boilers, but if one of their hot air furnaces can sit in a leaky tin shed for 20 yrs
cArNaGe wrote:stoker-man wrote:I have the sizing charts for cast iron radiators at work, but they will tell you the btu rating of any old radiator. The DF520 has a gross BTU of 215K and a net of 188K.
I'll look for them tomorrow.
So this confuses me. Gross verses Net. What does it but out? BTW: DF520 with oil back up in the PaperSHop for $950. Missed it!!!
billw wrote:.. I need to start reading the papershop online EVERY day.
Matthaus wrote:billw wrote:.. I need to start reading the papershop online EVERY day.
Not only every day but several times a day. I know who bought the EFM with the oil gun and he might be taking bids, we'll see if he shows his identity.