http://www.nora-oilheat.org/site20/uploads/FullRe ... cyTest.pdfrberq wrote: What I am trying to figure out is, what percentage of my oil bill is going purely to the boiler standby losses.
Check out page 7.
http://www.nora-oilheat.org/site20/uploads/FullRe ... cyTest.pdfrberq wrote: What I am trying to figure out is, what percentage of my oil bill is going purely to the boiler standby losses.
Wow! Thank you, Rob, that is exactly what I was looking for. If I am interpreting it correctly, my whole-house boiler with indirect Superstore tank for DHW is TERRIBLE when providing only DHW in the summer. It looks like it is only 38% efficient in terms of hot water delivered vs. oil burned. In the Winter, some of the standby loss could be captured to heat the house, though right now that is not happening except by accident. So at least for Spring/Summer/Fall, an electric heater would be an improvement. Not cheap, but an improvement.markviii wrote:Check out page 7.
rberq wrote:No, my boiler is cold-start, so if there is no call for heat from the Superstore tank the boiler itself can go stone cold. But in a sense you are correct, because during daylight hours there is often enough hot water use that the boiler never cools down completely. Therefore I have more or less continuous standby losses from the boiler and piping, except at night. What I am trying to figure out is, what percentage of my oil bill is going purely to the boiler standby losses.traderfjp wrote:You are keeping a boiler at 160/180 to heat water to about 125.
Makes sense to me, IF the boilers had been the same in both #1 and #2. With indirect, there are standby losses from the boiler AND the storage tank AND the piping in between. With tankless standby loss would be only from the boiler.SMITTY wrote:#1 & #2 comparisons on that link made no sense to me. #1 was cast iron boiler, tankless. #2 was cast iron boiler, indirect. In that chart, #2 is less efficient & wastes more oil than #1.
rberq wrote:Makes sense to me, IF the boilers had been the same in both #1 and #2. With indirect, there are standby losses from the boiler AND the storage tank AND the piping in between. With tankless standby loss would be only from the boiler.SMITTY wrote:#1 & #2 comparisons on that link made no sense to me. #1 was cast iron boiler, tankless. #2 was cast iron boiler, indirect. In that chart, #2 is less efficient & wastes more oil than #1.
In your situation, where you swapped out the boiler AND went from tankless to indirect AND put coils in the coal stove, it may be hard to tell which change(s) contributed how much to your savings.
The water usage pattern is also a factor. With frequent use, the indirect system will call on the boiler more frequently so it will never cool down all the way, therefore will have constant standby losses. In my personal circumstances this does appear to be true. Additionally, because my boiler can heat the whole house it is way over-size for heating just DHW, so there is all the more boiler and water mass suffering standby losses. And the long run of pipe between my boiler and the storage tank is lots more surface area producing standby loss.
Ahh ... now it makes sense!markviii wrote:Smitty, tests #1 and 2 did not use the same boiler. Note that the second one was not as efficient even in steady-state operation.
More $$$ for the plumber? More $$$ for my oil company which sold and installed the system, and more continuing $$$ for the excess oil burned? Ignorance on the part of the plumbers? Or just enthusiasm -- after all, if what you do is solder pipes, then the more pipes the better!traderfjp wrote:I could never understand why anyone would choose a boiler and indirect storage tank over a dedicated oil fired hot water heater. 99% of plumbers suggest the indirect system.
If installing a new system, an oil boiler installed with an indirect water heater would be cheaper to install than an oil boiler and a separate oil fired water heater when taking into account all aspects of piping, controls, venting, etc. Also, there is only one oil burner to maintain, not two.rberq wrote:More $$$ for the plumber? More $$$ for my oil company which sold and installed the system, and more continuing $$$ for the excess oil burned? Ignorance on the part of the plumbers? Or just enthusiasm -- after all, if what you do is solder pipes, then the more pipes the better!traderfjp wrote:I could never understand why anyone would choose a boiler and indirect storage tank over a dedicated oil fired hot water heater. 99% of plumbers suggest the indirect system.
I don't know how high your electric rates are. Ours are about 16 cents per kwh. So you made hot water for only $16 for the month. I'd be happy with that too.traderfjp wrote:I just received my first electric bill with the new hybrid electric heater. My usage was 100kw over last year.