Thinking about a tankless water heater in my barn.

[natto fire]

So, my wife and I have been going back and forth about turning the insulated part of our pole barn into a canning/event kitchen.

I have a 1" gas line there, which is teed down to 3/4" to a 60k BTU furnace. I definitely don't need crazy GPM or BTU for this water heater, as it will only be tied to a single commercial sink.

From my little research, it seems like 3.1 GPM is the low end. Almost overkill for me. I am on a well and doubt the stand pipe in the barn sees more than 2 GPM.

Hoping to get some suggestions on very low capacity vented or ventless gas fired tankless water heaters.

 

[echo4747]

any reason that you cant use a tank unit?

 

[natto fire]

any reason that you cant use a tank unit?

I suppose that is possible. Drain the tank after the season and use that stand pipe as it is meant to.

I feel like most tiny tanks are electric, and even though I have 100 amp service to the barn, I really prefer a gas solution.

 

[echo4747]

30 gal is the smallest nat gas I've seen ... you can drain it (or set it at the lowest setting) if you think it might sit idle and freeze. It would certainly cost less to purchase than a tankless. (often times scracth& dent units are available cheap) Not quite as efficient as a tankless but, for such a limited amount of use it will see, it may be an option for you.

 

[herm0016]

www.amazon.com/dp/B00388M4B4/ref=asc_df_B00388M4B44852674/?tag=hyprod-20&creative=394997&creativeASIN=B00388M4B4&linkCode=df0&hvadid=167126276842&hvpos=1o1&hvnetw=g&hvrand=18071626550864336348&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9028727&hvtargid=pla-275667025118#productDescription_secondary_view_div_1487816280314. Search for instant hot water heaters or point of use hot water.

 

[echo4747]

one thing that comes to mind is the temperature of the incoming well water. I have both well and municipal water at home.. my well water is a steady 52 degrees year round. My municipal water is much colder than 52deg in the winter and warmer than 52deg in the summer. with a tankless ... as flow rate increases temp rise decreases. with a tank (once heated) you will get the tank capacity at whatever temp you set it at regardless of flow rate. This may/may not be important for your canning projects

 

[NetWareHead]

One thing to keep in mind since you are on well water is the total amount of dissolved solids, water PH and overall hardness. A tank water heater is far more forgiving whereas a tankless will be more subject to fouling and reduction of performance as scale builds up on the heating elements.

Dont know how your gas lines are structured but you mentioned you have an inch gas line and tee'd down to 3/4. The tankless units I looked at wanted an inch line so you may add to expense to repipe your gas line. This all depends on how far the unit will be located from the pressure regulator or meter. Use this as a guide: http://www.endot.com/OpenFile.aspx?path=21eb7_0.pdf&Type=1&pid=34

Most tank water heaters can be supplied with a half inch line which will be easier to tee off of your existing setup. If you need large amounts of hot water at an "endless" rate than go tankless. But you may be able to satisfy your commercial demand with a simple 40 or 50 gallon tank heater from home depot. $500 + installl costs and you are done. Wrap it with a cheap insulating blanket for even more savings.

 

[NutBucket]

The 3.1 GPM rating is for a very low temperature rise...something like 30 degrees. We recently had to buy a new one and the effective GPM is about half of the inflated number they advertise.

 

[natto fire]

I forgot to mention in my OP that the water enters the barn in the non-heated portion, hence the self draining stand pipe.

It sounds like going with a tanked might be the way to go. I like the idea of gas for lower energy cost, but I think a little 7-10 gallon electric might be better for upfront cost. That would also make the draining at winter time less wasteful.

I have a 100A subpanel in the barn, so no problem with available electric.

Ned, that is a good point about the water quality. We have a softener and pre filter, and the rest of the plumbing fixtures seem to be in good shape. That said, the water to the barn and outdoor spigots bypass the softener, so it's hard to say how bad the water is sans softener.

Thank you everyone for your input. I am going to assess the options, but it seems like tankless is not worth the trouble in my scenario.

 

[Red Squirrel]

Honestly for a small application like that I'd probably look at an electric tank, have a switch/timer that you can turn on ahead of time before you want to use it. Then turn it off when not in use. That part is heated all the time right? So you could get away with letting the water get cold?

 

[Steve Logan]

For such a low demand you will be hard pushed to find a gas unit. Gas units are naturally higher capacity and more powerful. Would you be able to switch to an electric unit at all? They are much more energy efficient and come in smaller capacities with lower activation temperatures, they are also designed to be portable and many people use them in the RV's are other non residential ways. Have a look at this site http://tanklessheaterguide.com/ , its a review and comparison site which should clear up your options