[Shop-talk] Shop water heater

[Scott]

So my new garage has a bathroom in it. I like the feature very much, 
with one exception: it's on the opposite side of the house from the 
water heater.

It takes a few minutes of running the water to get hot water.  I don't 
want to run a pump, or plumb a loop, so I thought I'd install a water 
heater near the faucet and shower.

What I'm wondering is what kind and capacity I should use. My first 
thought was a small 6- or 10-gallon tank heater, and plumb it to the 
existing hot water line. I'd bet there are no more than two gallons of 
water in the lines, so by the time the small heater is out of hot water, 
the hot water from the main tank would be there. But then I wonder if I 
should go with a larger capacity second heater to minimize any 
temperature changes, etc.

Then I considered a tankless heater for the energy savings and felt a 
bad case of shipwright's disease kicking in...

I'm putting this thing in the attic and I'd like to get this project 
done. What do you guys think? A small tank heater, 6 to 20 gallons? What 
size? Or should I go for the tankless?

Thanks.

Scott