Gasifier making dhw in the summer?

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thearvman

New Member
Hearth Supporter
Nov 26, 2007
3
Northern Me
I am just setting up my Tarm Solo 60 with 1200 gallon storage. I would like to know if people fire their boilers in the summer to make domestic hot water? Also what are the concerns or pros/cons?
 
thearvman said:
I am just setting up my Tarm Solo 60 with 1200 gallon storage. I would like to know if people fire their boilers in the summer to make domestic hot water? Also what are the concerns or pros/cons?

just fired up mt system on jan 17th, but this is why I did what I did. I plan on using my system for dom water. I see no disadvantages in doing this. Right now I try to keep the storage up to 170ish, but when the heating systems over, I won't need to keep my tank up to 140ish? I'm making water to shower with as low as(tank temp) 120ish. I'm hoping only have to build a fire every 3 to 5 days in the summer.
 
I don't use dmw during the summer because I worry about the standby heat loss of my storage and piping. If I need to run the AC 15 minutes a day to overcome the heatloss, then i am likely not coming out ahead. BTW I haven't dialed in the total loss indoors yet, but much of my insulated pipe will lose > 20btu/h/ft and the storage is more difficult to figure, but Nofossil has an utility online that really opened up my eyes to possible losses from storage. I am working to make sure the heat storage room is well insulated and no subject to bleeding heat into the rest of the house.


Cali
 
I fire my boiler about every 5 days in the summer for DHW, usually with just limbs down around my woods(16 acres). I've got a 120' 3/4" copper domestic coil in my 957 gallon unpressurized storage. Family of 3 that other than me is not bashful about using hot water. I need to insulate my storage better and I know I could go at least a couple days longer.
 
DHW in the summer is definitely one of the best advantages of gasifiers with storage. Heatloss would have a minimal affect on the house temp because the water in the pressurized part of the heating system would need to run minimally or not at all to keep you in hot water between fires. Once my unpressurized tank is up to temp my DHW flows right through a coil in the tank. I can't imagine that my basement picks up even a degree of temp when the storage tank is charged, otherwise the heat wouldn't last long at all. (Besides, with my OB DHW coil that boiler was up around 150* all the time and it doesn't nearly have the insulation value my tank does. It probably added quite a bit of heat to the house.) If you run an indirect HW setup, then the only time pipes are hot are when reheating the indirect tank which is not very often. Just do it, it will save you a ton of money!
 
I have an EKO 60 w/ 800 gallons of storage in an open system. I have a side arm on my domestic hot water heater so it is pretty much off during the heating season. I really don't think I have an excess of DHW with this system, it works fine, but I question how well it would work during the summer. I only burn once per day 6-8 hours and rarely do I have to keep my fire going around the clock even when it's -15 degrees F. Some solutions that I am considering for summer DHW might be adding a smaller tank (maybe 200 gallons) and by-passing the large tank. I wouldn't think it would take long at all to charge smaller tank and keep it up to a 190 degrees of so. Any comments or ideas. Thanks. John
 
Like flyingcow, I'm new to this game, but plan on making hot water all year. My heat exchangers are plumbed with heat traps above the tank, so I don't really anticipate losing much heat at all. In fact, when I first fired my boiler all I had plumbed was the loop to storage and I heated it to 160 at the top of the tank and 112 at the bottom. A week later, the top and the bottom were within a degree or so of each other around 133, so I think all it did was mix.
Bub from Revision Energy, who recently made his first post here, says he's talked with several people that build fires less than once a week for their DHW in the summer.
 
thearvman,
This is the third winter season of use for my EKO40. The last two summers my dhw has been supplied by the EKO40. Currently we do not have storage so I have had to learn the "heat" cycle properties of my dhw tank which is propane. During the summer I fire the boiler in the evenings with about a half load (est. 3.25 cu. ft. of wood) and we're good until the next day. Storage may help me get to one extended fire per 5-9 days. When you can get wood at a good price you can save all year long. Otherwise watch the books. From what the paper said the other day energy prices are slated to go back up so summertime boiler-dhw may be something we all learn to like.
 
GibsonGuy said:
I have an EKO 60 w/ 800 gallons of storage in an open system. I have a side arm on my domestic hot water heater so it is pretty much off during the heating season. I really don't think I have an excess of DHW with this system, it works fine, but I question how well it would work during the summer. I only burn once per day 6-8 hours and rarely do I have to keep my fire going around the clock even when it's -15 degrees F. Some solutions that I am considering for summer DHW might be adding a smaller tank (maybe 200 gallons) and by-passing the large tank. I wouldn't think it would take long at all to charge smaller tank and keep it up to a 190 degrees of so. Any comments or ideas. Thanks. John

I solved this problem by putting a copper coil in my open tank for DHW. In the summer I burn about every 6 days and heat my storage to 170*. Then that hot water just sits nicely stratified and my DHW pulls heat from it through the coil until it gets down to about 130* and then I build another fire (6 days later).

Some people use indirect hotwater tanks or a plate hx to transfer the heat in storage to the DHW tank. With this method circulators must run every so often to reheat the DHW tank from the stored heat. This method may be a little less efficient as you would get some heat loss (but not much) from the piping between the two and turbulence in the tank can disrupt the good stratification. However, I think it probably works just fine with very minimal loss.

So your options are probably a coil in the tank or replacing your side arm with a plate hx. Or even replacing the DHW tank with an indirect one. I hope that helps.
 
When burning in the summertime... do your fires take right off?.. I mean.. is there a difference in the way your chimney works due to the different temps outdoors?(70 degrees instead of the -5 F I had this am).. or humidity? I do not have storage.. but would like 500 gallons pressurized. I think the attached garage will have to be built before the storage though. I think i can heat my hot water using a tank ( 250 gallons) of oil during the non heating season which is not too bad ? So it looks like 500 dollars of oil for the year.
 
Birdman said:
When burning in the summertime... do your fires take right off?.. I mean.. is there a difference in the way your chimney works due to the different temps outdoors?(70 degrees instead of the -5 F I had this am).. or humidity? I do not have storage.. but would like 500 gallons pressurized. I think the attached garage will have to be built before the storage though. I think i can heat my hot water using a tank ( 250 gallons) of oil during the non heating season which is not too bad ? So it looks like 500 dollars of oil for the year.

There is a little less natural draft due to the temp difference. Mine works fine in the summer, though it is subtly different to burn when it is hot out. Something always seem a little strange about it. It heats the basement up a little too while the fire is going, but it doesn't last long.
 
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