IS 740 GALLONS ENOUGH STORAGE FOR A SOLO 60?

[jimdeq]

Glad to see you jump in here Jabatty. I dont understand what you meant by 80* stored heat? My 70,000 btu heat loss was on my house. I also have 1200 sq/ft of shop with infloor tubes. The shop is very well insulated with 3 inches of spray foam and then a 2 x 4 fiberglass batt in a 2x8 exterior wall. The slab has 1.5" high density foam under it and around the perimeter.
1 1/4 " thermopex will feed the shop from 150' from the boiler. So thats the deal and I hope that 1110 gallons of pressurized storage will be the right fit for my setup?

 

[jebatty]

I dont understand what you meant by 80* stored heat?

What I meant was, if tank at 190F, and in-floor usable at 110F, then delta-T=80, and 80 x 8.33 x 1000 = 666,400 stored and usable btu's before the the tank needs recharging, and at 40,000 btuh heat loss, that's 16.66 hours of heat from storage at coldest conditions.

 

[jimdeq]

Awesome explanation. I get it now.

 

[RobC]

Dogwood, After burning for my DHW for a month or so ( superstor on it own zone ) 1 thing I noticed is that when the top of storage is 130 and needing a boiler fire the bottom of storage is 115 or so. With that cold water going back to the termovar mixing valve the boiler will cycle for much of it's burn.
What I'm getting at is that with my 1000G pressurized set up and needing 150 water for my fan coil during the winter the bottom of storage never gets that cold and the tremovar is open shortly into the boiler burn cycle.
My last DHW water fire I opened the ball valve ( allow more hot to mix ) on the tremovar and turned my circulator from speed 2 to 3. I haven't had time to stand around and look for an extended time but it looked to help get the boiler off idle some.
Conclusion is that having my 5 X 500 gallon stacked works well from a couple of different points of view.
As far as time between burns 90% of the time it's 1 to 1.5 loads a day in one burn. This forces me to have a fire every day which is good for me because I like consistency in my schedule. I'm not sure there would have been any benefit to having more storage.
Hope that helps. Rob

 

[jebatty]

1 thing I noticed is that when the top of storage is 130 and needing a boiler fire the bottom of storage is 115 or so. With that cold water going back to the termovar mixing valve the boiler will cycle for much of it’s burn.

I'm not clear on this, meaning, yesterday I fired my Solo 40, bottom of tank/supply to boiler was 95F, Termovar return to boiler was 150F, and the boiler was burning full out constantly, no boiler cycling. What was cycling is my circulator, which is set to "on" at 165F, "off" at 160F. With the 95F return water, the boiler could not maintain constant 160F+ output at the flow rate of the circulator, causing the boiler water to cool down, circulator "off," boiler water back up to 165F, circulator "on," repeat, etc. I had the balancing valve open enough to ensure at least 150F return water to the boiler; circulator flow rate to storage (flowmeter reading) was 3.5-4 gpm (120-140,000 btuh boiler output).

 

[RobC]

Jim, I need to play with settings more during the next couple of burns but I never seem to be able to pump the heat away from my Tarm 60 fast enough, even in winter. I am aware that higher circulator settings doesn't necessarily mean your pumping away more BTU's but I thought that was something to try and opening up the tremovar to allow more water to mix maintaining the 150 return temp.
During the winter I run with the balancing valve closed more than 1/2 way and circulator on 2, right now I have it set open more than 1/2 way and the circulator on 3.
Any way I haven't really had enough time to play with settings for summer use to make improvements.
Rob

 

[dogwood]

Thanks RobC. Guess I'll stick with the thousand I've got and see how it works out.

Mike

 

[heaterman]

1 thing I noticed is that when the top of storage is 130 and needing a boiler fire the bottom of storage is 115 or so. With that cold water going back to the termovar mixing valve the boiler will cycle for much of it’s burn.

I'm not clear on this, meaning, yesterday I fired my Solo 40, bottom of tank/supply to boiler was 95F, Termovar return to boiler was 150F, and the boiler was burning full out constantly, no boiler cycling. What was cycling is my circulator, which is set to "on" at 165F, "off" at 160F. With the 95F return water, the boiler could not maintain constant 160F+ output at the flow rate of the circulator, causing the boiler water to cool down, circulator "off," boiler water back up to 165F, circulator "on," repeat, etc. I had the balancing valve open enough to ensure at least 150F return water to the boiler; circulator flow rate to storage (flowmeter reading) was 3.5-4 gpm (120-140,000 btuh boiler output).

?? What particular circulator was cycling? Would this be between the boiler and storage? If so, I'm curious as to what the advantage or purpose of setting it up that way is.

 

[jebatty]

Rob C: with you circulator settings, you might have a 15-58. I also have that, and leave it on #2, plus I have a booster 007 in series which kicks in at 188F to increase flow and reduce possible idling. With the flow meter, there is a pretty good increase in gpm moving from 1 to 2 on the 15-58, but very little increase moving to 3, due to increase in pump head as flow increases. A 60 likely needs 1.5" piping, and a flow of 17 gpm to handle full output at high burn. I doubt a 15-58 will provide that flow, and if it does, head has to be really low and you are operating at the extreme of the curve; not the best scenario. I strongly recommend some homework to do a pump head calc at various flow rates and see if you can diagnose why you can't pull full output from you 60. I went down the road of hard knocks a couple of times before I really began to understand the relationship between piping size, pump head, and gpm flow. It's a moving target, but it can be done.

 

[jimdeq]

Rob ? When I was designing my storage loop, I was told to use a Grundfos 26-99 3 speed. I have very low head with my storage tanks directly below the boiler within 10 feet. Bioheat suggested this pump due to being able to move BTUS to storage. I dont have it installed yet,but I hope it's the right pump?

 

[RobC]

26-99 is a conclusion that I'm coming to on my system. I have the 15-85. It was on my unit, I bought stove plumbed and wired. My storage isn't directly next to my boiler which would amplify problems due to head etc. Honestly the calculation end of things isn't my best input for this forum but the 26-99 is likely where you want to be. Nothing wrong with running it on speed 1 either.
Are you going to be using the 1.25" tremovar and did they recommend that or did they set you up differently ?
Rob

 

[jimdeq]

Yes I will be using 1.25" termovar. I purchased a boiler package so it came with the package. I was going to order the termovar loading unit ,but it was suggested I didnt due to the pump size. They said they dont suggest the TLU for a solo 60 ( Too many BTUS).