Boiler System Improvements

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Countryboy1966

Member
Jan 17, 2011
57
NE, Ohio
I still remember the night last year in January where it was 15° out and my house temperature was plummeting past 50° because my boiler system was in a catastrophic failure. Thanks go you guys I gained the knowledge to realize I did a lot of things wrong.

This year I have moved my OWB 100ft closer to address a few issues and I currently experience minimal T Delta between the boiler and my heat exchanger where last year the delta was as great as 40°. I can now achieve 190° temp at my HX should I want it. Shoulder season was awesome. We enjoyed some really nice comfortable internal climate. Each of the last three years I have gone through 12 tightly packed cords by volume and this year I have gone through maybe 2-3 max so I’m expecting at least 30% less wood consumption.

I still believe I’m not getting the optimum heat exchange into my process water. I believe my delta is as much as 25° and I will admit I have a tough time gaining accurate readings since my only method to monitor is shooting copper pipe surface with an IR or the oil boiler temp gage in the house. I think I have two major issues being process water circ pump sizing and also my process water goes through the oil boiler prior to returning to the HX causing heat loss up the chimney.

I’m at the point where I want to invest in updating the process water system. My long term plan is to install storage, but it isn’t happening as soon as I thought, but I believe I can move forward with a system like shown in the sticky above while gaining efficiency and add storage later.

I’ve attached my current system along with two options I think are good options that I would like feedback on if you don’t mind. I will be more than happy to provide any additional information. Please keep in mind I did not add on all details like mixing valve for return to boiler.

Thank you in advance for your time!
 

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If you think one of your problems is circ pump sizing, I would address that issue first and foremost, before you go through the expense and hassle of re-piping the system inside your house. Since thats something that would need to be fixed eventually anyway, why not address it now? Is that something that folks here can help with?

As far as piping designs, I think you should lean towards the second one, since that would allow for the use of storage in the future fairly easily. You will need some more circ pumps, but I think that offers the flexibility you are looking for.
 
You have a bit of a mixed message there in your post. On one hand you said that moving the OWB closer gained a big improvement at the HX and the early season results were good; but also said you think there still may be an issue (based on uncertain temp readings). So, is there currently any problem heating the house when it's cold outside? If not, maybe you don't have anything to worry about. What you really need to know is how that 190* water coming into the HX is doing as it makes it's way through the rest of the system. I've found it extremely helpful having a bunch of cheap "frothing" thermometers at key piping points in my system. I can tell at a glance how the water temp changes as it goes from WB, through the OB (series), through the zones, returns to the OB, and then returns to the WB. You could set something like this up for small $$, or go higher tech and use one-wire sensors. Or, for a quick check, paint some black spots on the copper/pex and use your IR (you'll need to be fast on your feet and quick on the trigger for that). If you can get those temps (accurate relative to each other), you will know what changes (if any) you will need to make. Lastly, based on temp readings into and out of my OB, I don't believe there is a huge loss going up the stack (some yes of course). There is definitely a standby loss radiating from the OB, but that goes directly toward heating the house. If I have to cut wood for an extra day or so to offset the heat up the stack, that's no big deal to me ;-)
 
Thanks for the responses so far.

I have not gone trough the circ pump calculation, but I'm concerned about the circ pump in the house and if it matches right for the OWB supply.

No doubt what I am saying may be confusing. I'm a newb trying to learn this process a bit. The contradicting statement regarding temp readings: I have a boiler clean on my OWB supply in right before the HX. I burp it and take a temp reading of the water itself. I'm confident of this reading and my gages on my OB and OWB, but not so on any others because of the inaccuracies of the containing medium I.e. copper.


I know the system is far more efficient compared to years past, but I would like to think I can squeeze more out of it from the thinking I can't have dumb luck that everything else in the balance of the system is optimal.

My biggest indicator is my boiler temp gage right before going into the HX(see current). It reads 140° when I know my boiler water is and has been a constant 180°. All cirulation pumps are constantly on at this point.

On a continuous system I'd like to think that the temperature deltas should be much closer. I've ran my boiler up to 180° for a constant length of time and the best temp I've found in my oil boiler is 150°. I know I lose a certain amount into the house in the form of heat and I don't have all the pieces to the monitoring process, but there is enough to tell me something is up. Perhaps I'm expecting more than I should?

I'll stop at the store and get some thermometers. More info tonight.
 
If you buy some type of cooking/frothing therm with a dial and a stem, make sure to sync them all up using boiling or ice water (ambient temp probably also works ok). After the sync, be careful not to twist the dial after anchoring the stem on the pipe - they move out of adjustment very easily. You can tape the stem tip area directly onto the pipe with a hi-temp tape - I use ASJ which is great stuff, but other tape would also get the job done. Then, after taping, cover as much of the stem as possible with pipe insulation, adding duct tape to seal the whole thing up (but the entire stem doesn't need to be insulated). The dials stick out from the pipe at an odd angle, but they do give very close, accurate readings if the insulation job is consistent. Hope these therms provide you with enough additional information to figure out what's going on.
 
willworkforwood said:
If you buy some type of cooking/frothing therm with a dial and a stem, make sure to sync them all up using boiling or ice water (ambient temp probably also works ok). After the sync, be careful not to twist the dial after anchoring the stem on the pipe - they move out of adjustment very easily. You can tape the stem tip area directly onto the pipe with a hi-temp tape - I use ASJ which is great stuff, but other tape would also get the job done. Then, after taping, cover as much of the stem as possible with pipe insulation, adding duct tape to seal the whole thing up (but the entire stem doesn't need to be insulated). The dials stick out from the pipe at an odd angle, but they do give very close, accurate readings if the insulation job is consistent. Hope these therms provide you with enough additional information to figure out what's going on.
Click to expand...

Thanks for the tips. I mocked up with electrical tape but will have to go back later with high temp. It just wasn't doing the job. I hear you on the syncing. I have an aluminum anodizing line and I didn't realize those things were adjustable. Talking about varying process parameters.

I then performed the spraypaint suggestion and on my 2" copper pipes it was a perfect fit. Learn something new every day.

So while my boiler running a constant temp:

OWB Supply in: 169°
OWB Supply out: Unknown could not get good reading will need to get probe on it.
Process water supply out: 167°
Process water supply in: 158°

It appears I may not have any problems. Those numbers seem acceptable.
 
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