Need Recommendations on point of use electric water.heaters

Mad Dog_2

Hey You'll. I have a situation where we don't have the amps for a Stiebel Eltron (Which i gave had great success with).  I love Bradford White so I am looking at the quick shot model.  Any experience?  Thank you . Mad Dog

hot_rod

Looks like the KwickShot needs a 30A circuit, what do you have available? I doubt you get much capacity with any less than a 30A?
Unless you go with a 2.5 or 6 gallon tank style, those run on a 20A 120V circuit.

Jamie Hall

It's all about watts and flow... unless you can have a small under sink tank, but they don't have a whole lot of capacity (like 3 to 7 gallons... Navy showers, anyone?). It's going to come down to the flow rate of the fixtures vs. the electric power you have available (and possibly the voltage).

Mad Dog_2

Thanks HR & Jamie.  Yep we got 30amps alloted for that.  That will be fine. Its a simple country cottage KS, Lavatory Shower none of which will be used more than 2 out of 3.  Mad Dog

Larry Weingarten

Hi, I've known people to get by just fine on a 120 VAC, ten gallon tank. Low flow showerhead (like 1.5 gpm) helps!

Yours, Larry

hot_rod

Is space at a premium? If not the larger the tank, the more run time. If a small tank is the only option, run it hot, maybe 150 and use a thermostatic mix valve 

30A can run a 5500w element 
5500 x3.41= 18,755 btu. Probably not going to get you much in a tankless type DHW unit 

500.flow. Delta T, is the math

so about 1/2 gpm at a 70 degree rise in a tankless

Mad Dog_2

This is the option boys:

1) just use existing 3/4" X 50 feet  insulated Pex that is buried 4 feet down from the main house to the guest cottage off of existing Propane-fired 65 gallon tank.  This was done 20 years ago and I would have insulated even better with today's products .
I could do a HW return to save on water waste emptying out the 50 foot cold slug in the hot water supply when faucet is opened. But I'm concerned that the frigid Catskill Mountan Permafrost will cause a lot of unnecessary heat loss and fire the tank too much.  However, the new HW load is only a Shower, KS and Lav, so I have the tank capacity..
2) Do a Small Stiebel Eltron (which I have had great success with, but will need to do wire and panel upgrade with the great amp load. $$$)
3) 3 small individual point of use elec water heaters  or one under KS and one for shower and Lav.  Just not impressed w the quality of the units I have seen..
4)Yes. Space is a premium.   I could put a 5 or 10. Gallon electric in the loft.   

Need help deciding guys.  Its basically a Year round Catskill Rental property we own for skiing and Hunters, Trout fisherman so, were trying to stay simple, easy to maintain and reliable in this cozy cottage. What would you'll do?  Thanks so much. Mad Dog

yellowdog

im a huge fan of the stibel eltron's. i would do the electrical upgrade so you could use one.

Robert_25

How about a compromise? A tank you can fit in the loft, run it hot and mix down to 120F, and supply it with water from the remote propane water heater.  The kitchen and bathroom sinks will get hot water quickly from the small tank, and the remote propane unit will ensure your guests won’t run our during a period of high demand.  

Jamie Hall

I really think I would run probably two of the little 4 gallon 110 volt water heaters like this one: https://www.amazon.com/dp/B07RS4VL8L/ref=sspa_dk_detail_0?pd_rd_i=B07RT71RYH&pd_rd_w=VIXSW&content-id=amzn1.sym.9f074495-da4d-4e1c-b407-69e85fa47fdb&pf_rd_p=9f074495-da4d-4e1c-b407-69e85fa47fdb&pf_rd_r=P9DDCBE6T0ZQYFHBPRGB&pd_rd_wg=gDmIP&pd_rd_r=d0f96855-a521-4fa2-81ab-3e7980ee8ce2&s=hi&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzU1MwUUgwMDdJVkk2JmVuY3J5cHRlZElkPUEwODQ3MjEyMUpTREQ0TzVUQ0M0USZlbmNyeXB0ZWRBZElkPUEwMDU2MTE2MlBSN1k4TFFVVEVNUiZ3aWRnZXROYW1lPXNwX2RldGFpbF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1
You're not be boing to take long showers, but it would be ample for a short shower. I've used them and they seem to last well.

Jamie Hall

Same company also makes a 7 gallon size -- better for showers, perhaps.

Larry Weingarten

Hi @Mad Dog_2 , A thought. Run water and measure how many gallons you need to run out before hot water arrives. Triple that number and then install a tank of that size. For example, it you need to run out three and a third gallons, put in a ten gallon tank. This way, the dip in temperature is hardly noticeable to the one taking a shower. Also, if you have the choice, based on available pressure and desired flow, install the smallest line you can. Anything you can do to reduce the number of gallons between heat-maker and point of use will make things work better and faster. So, if you can put in, say a half inch line because you have sixty psi, the amount of cold water will be roughly half of what it would have been with a 3/4" line. A one, or one and a half gpm showerhead will help. Appendix M of the plumbing code might help. Look up the "Water Demand Calculator" app too!

Yours, Larry
ps. A crazy thought. If you've got the pressure, you could pull a 3/8" line through the 3/4" one!

hot_rod

Only YOU can decide how much dhw capacity is adequate. Or how much time and effort you want to spend for "more than enough:)

What I have learned with water and hot water, in some cases you learn to live with what you get.

We lived in a cabin in Montana and hauled all our water in 5 gallon containers. You can shower with just a few gallons when you are trudging through feet of snow with 42 lbs of water.

And it build character for you and the family, learning to live with the least amount of DHW.

The kids, grandkids will talk about the cabin with 2 gallons of hot water for the rest of their lives. Hopefully in a bragging way.

If it is a summer cabin, an outdoor solar shower can be fun.

Mad Dog_2

Thanks You'll ...great ideas. Larry you should be granted a PE from somewhere!  Those charts have stared me in the face for years..time to use it.  Tanks Hot Rod...I agree.."Navy showers" is what we got in our summers up with The Racetrack  🐎 in  Saratoga , August Rental with well water and a very small electric HWH.  We made do!  Mad Dog

hot_rod

decades from now the family will talk about the time that old man M-dog put the 2 gallon WH in the summer cabin. With fond memories and a smile on their faces.