DHW during summer from Tarm Solo 60 w/500G storage and 60 Gallon super-heated superstor tank.

[MrEd]

Hi all.

I am wondering what the likelihood for success of getting my DHW off of my Tarm Solo 60 with (just) 500G of heat storage? I am thinking of buying the Superstor SSU-60, and am confident that during my normal heating months this will give me the hot water I need. Especially if I go the route of superheating the superstor and using a mixing valve.

What I am curious about, is how much of a hassle am I going to have heating DHW for the summer months. I really don't want to build a fire everyday in the summer, maybe 2 per week max is what I would want to lock myself into, but with a family of 6, a washing machine that probably runs at least once a day, and a dishwasher that runs twice a day on normal occasions, anyone care to venture a guess on how happy I would be with the described setup? and how long I would be likely to be able to go between fires.

I really don't have a good sense of how many usable gallons of hot water I will get out of a fully charged, superheated 60 G superstor, with 500G on tap to replace some of the lost heat....

Opinions?

 

[chuck172]

Ed,
I have the Solo40, 500 gallons of storage. 30 gallon superstor
Family of three. Large amount of hot water use. Average 2 whirlpool tubs, three showers and 1 load of dishes a day.
I'm starting a fire every 3-days. I bring the storage up to 190-195*
Bring the superstor up to about 160*

 

[MrEd]

Ed,
I have the Solo40, 500 gallons of storage. 30 gallon superstor
Family of three. Large amount of hot water use. Average 2 whirlpool tubs, three showers and 1 load of dishes a day.
I'm starting a fire every 3-days. I bring the storage up to 190-195*
Bring the superstor up to about 160*

Thats good to know. Every 3 days isn't bad, and with a superstor twice as big it should make a difference with my bigger family size. Are you superheating your superstor or keeping it more like 115?

 

[chuck172]

I superheat the superstor when I charge the storage tank, then I turn it down to about 120*

 

[Nofossil]

I have the 40 gallon Superstor and a 50' preheat coil in my 880 gallon storage tank. With a family of four (including a teenage girl) I get up to three days on a 160 degree charge, without the storage being particularly hot (around 120 at the top).


I like the Honeywell AM101 mixing valve for this application because it allows an output that's as close as 3 degrees to the hot inlet. I use two of them to get maximum mileage out of my preheated water: http://www.nofossil.org/site/index.php?choice=hotwater

 

[flyingcow]

I don't have a superstore, but I'm able to go 3 days pretty easily on a fire.2 adults, 3 kids, 15yrs/13yrs/10yrs old. Figure at least 4 showers a day plus loads of clothes/dishwasher etc. I only bring the tank temp up to about 165, once in a while 170. If i wanted to take the time and reload about another 1/3 of a load of wood and drive the tank up to 180, which should bring the middle up to 175, I should be able to get 4 days between fires. I suspect once the kids are out of school, less uniforms from ball games and a little less showering I'll be pushing 4 days with the same amount of wood.

 

[pybyr]

I don't have a superstore, but I'm able to go 3 days pretty easily on a fire.2 adults, 3 kids, 15yrs/13yrs/10yrs old. Figure at least 4 showers a day plus loads of clothes/dishwasher etc. I only bring the tank temp up to about 165, once in a while 170. If i wanted to take the time and reload about another 1/3 of a load of wood and drive the tank up to 180, which should bring the middle up to 175, I should be able to get 4 days between fires. I suspect once the kids are out of school, less uniforms from ball games and a little less showering I'll be pushing 4 days with the same amount of wood.

flyingcow-- so you're doing that just based on the hot water coil in the 820 gallon square tank? and do I recall that the 820 gal square tank comes with a a 'tempering valve' to blend to a consistent, non-overheated DHW temp regardless of what the temp in storage is?

thanks

 

[chuck172]

Sorry for the mistake, like nofossil I have the 40 gallon superstor, not the 30 gallon.

 

[Chris Hoskin]

Mr.Ed,

I think you are a bit optimistic about firing frequency given that you 'only' have 500 gallons of storage. Based on our experience and what the other posters have said I think every couple of days you will need to re-fire.

Five hundred gallons is a bit small for the Solo Plus 60. What you would like to see in a perfect scenario is that the boiler runs out of wood JUST as the tank gets up to say 185 or 190 degrees. The Solo Plus 60 has quite a large firebox, so i think you will have to experiment with different sized fuel loads to get close to this ideal situation. In other words, I don't think a 500 gallon tank will be able to absorb all the heat generated by a full fuel load in the Solo Plus 60 (assuming you are only letting your tank temps get down to around 140 or 150). Don't be afraid to 'over-insulate' the tank too, especially if you are aiming for very high tank temps.

The main thing you want to avoid is long periods of time when there is a partial load of wood in the firebox and no load (smolder, smoke and creosote build up leading to premature boiler rot).

One thing you might aim for too is to time laundry and hot tub use with firing of the boiler. Again kind of an ideal scenario that is easier said than done! Life does get in the way, eh?!

Bottom line, I think if you play with the fuel load size this is going to work great for you.

 

[flyingcow]

I don't have a superstore, but I'm able to go 3 days pretty easily on a fire.2 adults, 3 kids, 15yrs/13yrs/10yrs old. Figure at least 4 showers a day plus loads of clothes/dishwasher etc. I only bring the tank temp up to about 165, once in a while 170. If i wanted to take the time and reload about another 1/3 of a load of wood and drive the tank up to 180, which should bring the middle up to 175, I should be able to get 4 days between fires. I suspect once the kids are out of school, less uniforms from ball games and a little less showering I'll be pushing 4 days with the same amount of wood.

flyingcow-- so you're doing that just based on the hot water coil in the 820 gallon square tank? and do I recall that the 820 gal square tank comes with a a 'tempering valve' to blend to a consistent, non-overheated DHW temp regardless of what the temp in storage is?

thanks

Yes I'm doing that with the DHW coil only. And yes it has an anti-scalding valve that has a maximum output of 120 degrees. According to my temp gauge just a few feet from the coil, it's closer to 115(very hot if you run just the hot water tap wide open). When the tank gets down to 120 or less, I'll get a DHW temp of about 110. If you try to take a shower and run the dishwasher or clothes washer at the same time it'll drop down to about 90 pretty quick. This is not a problem when the tank temp is medium/high, the coil handles the volume pretty good. As i said before, these coils are another generation ahead of the old designs. I've taken a shower when the tank is at 102/105/115, it was comfortable. The women thought otherwise...............
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When the system was just started, I heated my DHW thru an Amtrol boilermate(30 gals?) that was set up with my oil system. Wouldn't have good water temps if tank got down below 140ish. Only did this for a few weeks, than the installer came back and finished the job. A lot better use of the system.

 

[Rory]

Like flying cow, my DHW coil is in my tank, in my case 180' of copper inside a homemade 670 gallon tank which also houses two 120' coils hooked up in parallel as a heat exchanger. It's just my wife and I, and so far my best stretch was a week between fires. This cool weather keeps getting in the way of repeating that, though.