Pushing the limits

[peakbagger]

-18 degree F overnight. I was definitely pushing my 500 gallon storage capacity overnight. I maxed it out before bed and was still running on storage this AM but temp was low so my standard baseboards were having a tough time bringing up the house temp. It has warmed up to a balmy -11 at 11 AM and the house is finally up to temp, storage is at max and I have my dump radiator running in the basement to use up some extra heat so the boiler doesn't overheat. I could have pushed all the heat to the house and skipped storage but expect my lack of baseboard would probably require more baby sitting then just letting it run.

Nice when a system runs as designed.

 

[velvetfoot]

It was-19 here this morning. I let my buffer tank cool off overnight so the top was at 140 before the boiler started. With the 4 degree setback recovery and the cold return temp from the bottom of the tank, it took a while to heat up the zones. I am thinking of putting a motor valve bypass around the tank, keeping the supply temp at a set value, with the excess going to the tank until it gets charged up.

To short of simulate, I've valved off the tank manually with the zones running and things heat up a lot quicker. Even though we have different boiler types, I can't see why a tank bypass wouldn't make getting more heat to the house quicker and more automatic for both of us.

 

[Fred61]

I need these -18 degree mornings every now and then to re-assure myself that my system is up to par and that my burning regimen is working as planned. Shut down boiler at 8:30 PM with the storage temperature at 182. This morning I made the rounds checking the three zones and storage temperature which was at 142 degrees. Couldn't wipe the smile off my face.

 

[wolfe64]

-18 degree F overnight. I was definitely pushing my 500 gallon storage capacity overnight. I maxed it out before bed and was still running on storage this AM but temp was low so my standard baseboards were having a tough time bringing up the house temp. It has warmed up to a balmy -11 at 11 AM and the house is finally up to temp, storage is at max and I have my dump radiator running in the basement to use up some extra heat so the boiler doesn't overheat. I could have pushed all the heat to the house and skipped storage but expect my lack of baseboard would probably require more baby sitting then just letting it run.

Nice when a system runs as designed.[/QUOTE

Sounds like your dump radiator is similar to mine. I don't currently have storage. My dump radiator is a bypass loop from the supply line running through a garage heater. It is controlled by an aquastat set to turn on the garage heater when the temp at the boiler is 185. Will be installing storage this spring. At what point in your system and at what temp do you set your dump radiator to turn on?

thanks.

 

[tom in maine]

-19.6F this morning on the Glorius Maine Coast. Big sea smoke!

 

[maple1]

It was-19 here this morning. I let my buffer tank cool off overnight so the top was at 140 before the boiler started. With the 4 degree setback recovery and the cold return temp from the bottom of the tank, it took a while to heat up the zones. I am thinking of putting a motor valve bypass around the tank, keeping the supply temp at a set value, with the excess going to the tank until it gets charged up.

To short of simulate, I've valved off the tank manually with the zones running and things heat up a lot quicker. Even though we have different boiler types, I can't see why a tank bypass wouldn't make getting more heat to the house quicker and more automatic for both of us.

I accomplish the same thing, if I want to, just by turning up all my thermostats (4 of them, 4 zones) at the same time.

That gets my load pump pumping its max flow, which is pretty close to or maybe even a bit more than my loading unit pump. Which means the load pump is pulling in all of what the loading unit is putting out, and very little is going to storage. Once return temps get above 140 (fairly soon, since no cold storage water is coming in, just return from zones), the loading unit stops bypassing and all flow is going through the zones, and since at that point the pumps are working in series, flow is greater than it normally would be through each. My boiler return temps will climb to 160, and supply to 180-185. Then as the zones drop out, less flow goes through the zones, the load pump slows, more flow goes through storage and boiler temps eventually settle to 140/160-165 for the storage charging.

 

[peakbagger]

I could do a lot of upgrades to my system but I am at the point where everything works as needed and would be hard to justify an upgrade as realistically until the boiler fails and I replace the boiler I cant justify it. I do have a manual switch that bypasses the storage. I use it on startup of the boiler. Its problematical as if I don't swap it over at the right time, the boiler get too warm and closes the air damper or even runs the dump loop. The boiler has a small firebox so normally I just swap it over to storage when I do the second loading after light off. I am pretty well resigned that if I ever move, the system is too complex as it is and most likely the recommendation will be to remove it as it would scare away most buyers. The oil boiler and its controls remain in place and act as a backup. I set it up that if the power is turned off to the wood boiler control, the oil system automatically reverts back to operating as though the wood boiler and storage was never installed. The biggest bang for my buck would be to replace or add to my radiation so that I can get away with lower supply temps but looking at cost/benefit including current NH incentives on minsplits I would be better off installing another minisplit and keeping the wood boiler as it has proven a couple of times that it can handle the really cold stuff.

I am in the same shape with solar electric and solar hot water both systems could have some changes or automation but they work perfectly well to cover my needs.

I guess the biggest project I need to do is make up a details owners manual of the household systems with lots of pictures and arrows.

 

[velvetfoot]

I accomplish the same thing, if I want to, just by turning up all my thermostats (4 of them, 4 zones) at the same time.

I've noticed the same, with my two zones. Thing is when one zone drops out the return temp plummets (still protected by the TermoMix) and supply temp also goes down, slowing down recovery of the zone that's on. Then, when all zones drop out, I'm charging storage at 100% with the low return them, which for you guys, is unavoidable, but by PB modulates down.