Froling Add-on Install

[Marshy]

Water is flowing and will be filled tonight.

The plumbing was pressure tested with air and is tight. I'm finishing up some wiring to the BLT controller and the boiler pump behind the tank then should be able to fill the boiler water jacket.

The well is taking it like a champ. Plenty of water in the ground this time of year. Mighty tasty too.

 

[brenndatomu]

 

[Marshy]

Just a little tease.

 

[maple1]

I think this is the longest tease I've seen on here - been a long winter, lol.

 

[Marshy]

I think this is the longest tease I've seen on here - been a long winter, lol.

Absolute truth.

 

[Fred61]

Going to be difficult to access the performance 'till next winter. Another long waiting period.

 

[Marshy]

I only have about 1/2 to 3/4 a cord of dry wood right now. Going to be burning lots of ash this coming winter.

I'll post some learnings thst I had about the BLT controller. It may benefit @jpelizza with his storage tank hes trying to install.

 

[Bad LP]

Why did you choose to use the BLT controller?

 

[Marshy]

Why did you choose to use the BLT controller?

Two main reasons;
1) Its a seamless way to integrate the wood boiler/storage bank system and the existing oil boiler with the ability to put the wood boiler in lead with automatic transfer to the oil boiler for backup.
2) I purchased the wood boiler through Tarm and I'm not capable of building a control scheme by myself. Their product is tried and true and has instructions and is built to be used generically with any kind of source for a backup.

The Froling boiler does not have the ability to provide the BLT function. Maybe in the future they will but not this model.

Now if theres some sort of emergency and I cannot get home to load/fire the boiler the house will stay warm with the oil as backup when the storage tankndroos below a certain temperature that I can set.

 

[Highbeam]

Two main reasons;
1) Its a seamless way to integrate the wood boiler/storage bank system and the existing oil boiler with the ability to put the wood boiler in lead with automatic transfer to the oil boiler for backup.
2) I purchased the wood boiler through Tarm and I'm not capable of building a control scheme by myself. Their product is tried and true and has instructions and is built to be used generically with any kind of source for a backup.

The Froling boiler does not have the ability to provide the BLT function. Maybe in the future they will but not this model.

Now if theres some sort of emergency and I cannot get home to load/fire the boiler the house will stay warm with the oil as backup when the storage tankndroos below a certain temperature that I can set.

Plus BLT makes everyone think about a bacon sandwich and that makes us happy.

 

[Marshy]

Bacon is cooking.

 

[Marshy]

My lower tank sensor is still reading 50F and the upper is 163F last I check about 20 mins ago. I put a little more wood in the boiler to finish charging and run for the night. Anyone have advice on what I should do about the sensor? Hard to believe 50F is accurate. For that matter, I hope it's not the top one that's faulty and I have top and bottom swapped.

@Chris Hoskin, can I take a resistance reading on the temp probe and determine if it's good?

 

[jebatty]

If those were the sensors on my 1000F pressurized horizontal storage tank, and I just filled the tank with 50F well water, and then started the boiler, that bottom sensor would stay at 50Ffor a long time as the hot temperature level gradually moved down the tank. So, you just may have excellent stratification which is desirable in most situations. Adding a middle of tank sensor would show the stratification more clearly, as it would start to rise while the bottom stayed at 50F. In fact, unless you have mixing occurring in the tank, I am not surprised to see top of tank at that much higher temperature while bottom of tank still remained at 50F.

 

[maple1]

Do you have any more temp readings? Like boiler in & out? Have an IR gun or other thermometer with probe/sensor you can get some pipe temps with? Pipe temp coming out of storage back to boiler return should tell a tale. I would think it would rise pretty gradually as the stratification layer falls.

Also you should be able to rough in an approximate time to charge your storage based on wood load and/or burn time. It will take a fair amount of burn to charge things all up from all cold, and stratification like that is likely what you should see until the tank gets fairly full of BTUs - although I don't have a coil setup so no direct experience watching one of those charge up. It might take a while for bottom temp to rise and that cold slug at the bottom to get mixed in - vs. a pressurized direct hook up pulling that slug right into the boiler. How close to the bottom sensor location is the bottom of your coil? How far off the bottom is the bottom of the coil? Vertical separation, that is.

 

[Marshy]

Do you have any more temp readings? Like boiler in & out? Have an IR gun or other thermometer with probe/sensor you can get some pipe temps with? Pipe temp coming out of storage back to boiler return should tell a tale. I would think it would rise pretty gradually as the stratification layer falls.

Also you should be able to rough in an approximate time to charge your storage based on wood load and/or burn time. It will take a fair amount of burn to charge things all up from all cold, and stratification like that is likely what you should see until the tank gets fairly full of BTUs - although I don't have a coil setup so no direct experience watching one of those charge up. It might take a while for bottom temp to rise and that cold slug at the bottom to get mixed in - vs. a pressurized direct hook up pulling that slug right into the boiler. How close to the bottom sensor location is the bottom of your coil? How far off the bottom is the bottom of the coil? Vertical separation, that is.

Great insight, I wish I knew the dimensions for the coil relative to the tank like you are askin. I know one thing for sure, I filled the tank with water then realized I should have lengthened the pipe so the boiler would sit lower in the tank. There is about 1/2 of a coil sticking out of the water line, so about 3" vertical above water line. There was no way to remove the coil without getting in the water unfortunately.

The sensor appears to be fine, its reading and I can see I underestimated the amount of time it takes to get that stratification layer to sink. Maybe I should put the pump on medium speed?

The last picture I posted was with the boiler only into the first 3 or so hours of the very first burn. I had my wife do a hot reload last night before she went to bed and she loaded it up to the bottom of the loading door to get the tank close to fully charged. Here is is this AM.

 

[Chris Hoskin]

Great insight, I wish I knew the dimensions for the coil relative to the tank like you are askin. I know one thing for sure, I filled the tank with water then realized I should have lengthened the pipe so the boiler would sit lower in the tank. There is about 1/2 of a coil sticking out of the water line, so about 3" vertical above water line. There was no way to remove the coil without getting in the water unfortunately.

The sensor appears to be fine, its reading and I can see I underestimated the amount of time it takes to get that stratification layer to sink. Maybe I should put the pump on medium speed?

The last picture I posted was with the boiler only into the first 3 or so hours of the very first burn. I had my wife do a hot reload last night before she went to bed and she loaded it up to the bottom of the loading door to get the tank close to fully charged. Here is is this AM.

View attachment 226307

Excellent. Those coil-type tanks set up a very, very sharp thermocline because there is no stirring of the tank from flow. You might find a couple of more mid-tank sensors eventually.

 

[Bad LP]

Excellent. Those coil-type tanks set up a very, very sharp thermocline because there is no stirring of the tank from flow. You might find a couple of more mid-tank sensors eventually.

So would that imply that there are not as many stored BTU's waiting to be released?

 

[Marshy]

Next time I fire the boiler I'll run the boiler side circulator on high speed and see what happens. I'm cerious if I can get the lower half of the tank closer to 100F while keeping the upper half less than the maximum tank liner temp.

 

[jebatty]

I have no experience with an open system and maximum temperature limit for an open system tank liner. I would think, however, that if the system is being actively used, hot water from top of tank to emitters and return water to bottom of tank, the tank will mix sufficiently to avoid the maximum temperature limit. Your immediate issue may be related to low use of your system. On the other hand, If during normal use sufficient mixing does not occur, then you may have to reduce your boiler firing as needed to limit top of tank high temperature. An alternative possibility would be installing a circulation pump for the tank to provide the needed mixing and reduce top of tank temperature. Other strategies may exist.

 

[Marshy]

I have no experience with an open system and maximum temperature limit for an open system tank liner. I would think, however, that if the system is being actively used, hot water from top of tank to emitters and return water to bottom of tank, the tank will mix sufficiently to avoid the maximum temperature limit. Your immediate issue may be related to low use of your system. On the other hand, If during normal use sufficient mixing does not occur, then you may have to reduce your boiler firing as needed to limit top of tank high temperature. An alternative possibility would be installing a circulation pump for the tank to provide the needed mixing and reduce top of tank temperature. Other strategies may exist.

I have a lot to learn about these unpressurized tank systems but from what I understand stratification is is desirable and because the water in the tank does not circulate they stratify well. I believe when there's is high demand the tank will not be stratified as much because the return water from my zones could be as high as 165 (max). Because the returning water enters the coil at the bottom of it the lower part of the tank will heat up to normalize ... I've seen this already.

First and only fire was 4/30. Her was the tank temps morning of 5/1.

Here is the tank temps this AM.

The returning water from the zones are heating the lower half of the tank when it was cold. I think once the system gets operated enough the lower temp will probably follow the returning water temps closely. A temp sensor on the inlet of the htx would tell the full story.

 

[Marshy]

Excellent. Those coil-type tanks set up a very, very sharp thermocline because there is no stirring of the tank from flow. You might find a couple of more mid-tank sensors eventually.

If I ever drain the tank I certainly will add some. I'll also lower the coil into the tank another 4". Until then I'll probably consider adding temp probes on the htx inlet and outlet.

 

[Chris Hoskin]

So would that imply that there are not as many stored BTU's waiting to be released?

No, better stratification means MORE btu's available. The higher the highest temp in the tank, the more btu you can extract from the tank. For example, lets say you have a tank that is well mixed and 140F top to bottom and a different tank that is 160F at the top and 120F at the bottom. Even though both tanks might have the same number of btu stored, the tank with 160F at the top can DELIVER more heat to the building. In this example I am assuming hot water baseboard or hydro-air and a traditional indirect water heater - if the house is all radiant floor, for example, there is probably no practical difference in the two tanks ability to heat in this example.

 

[maple1]

If I ever drain the tank I certainly will add some. I'll also lower the coil into the tank another 4". Until then I'll probably consider adding temp probes on the htx inlet and outlet.

I am thinking there would be a catch-22 with coil location? Like, if you lower it you might pull more BTUs out of the coil when charging - but flip side would be you wouldn't have as much of the hottest water at the top available to the coil? Might be a negligible thing....

 

[TCaldwell]

Not disagreeing with the above but why not mix the tank when firing and bring it all up to one temp, then allow the cooler return to create the stratification.

 

[Marshy]

I am thinking there would be a catch-22 with coil location? Like, if you lower it you might pull more BTUs out of the coil when charging - but flip side would be you wouldn't have as much of the hottest water at the top available to the coil? Might be a negligible thing....

I wouldn't lower it far, right now there is about half of a coil above the water line. That equates to about 3" vertical height above the water line at the top of the coil. The lost BTU's from that being above the water line is likely more significant that if the coils was already fully submerged and just was lowering an additional 3"... Not a huge deal in either case as explained by Tom from AST. I just didn't realize it wasn't going to be fully submerged until the tank was 1/4 to 1/2 full. All that copper work I did, it wouldn't have been anything to lower it had I know before hand.

Not disagreeing with the above but why not mix the tank when firing and bring it all up to one temp, then allow the cooler return to create the stratification.

The stratification of the tank is important for overall heat transfer reasons. The heated water enters the coil at the top of the tank and travels towards the bottom. The stratified tank ensures a high delta T for the best BTU transfer rate across the whole coil. If the whole tank is nearly the same temp the heat transfer rate will be poor at the bottom and reduce the overall heat added.

That's my understanding and "in a nut shell" explanation. Anyone feel free to chime in.