Point of Use Water Heater

[Rob Bodenschatz]

I want to install a point of use water heater for the future sink in my shop. Basically, this sink will just be used for cleaning brushes, watering plants, washing hands, etc. This will not be inline with another water heater; it will be the sole source of hot water. I don't know anything about these heaters but I see they come in different sizes, 2, 4, 6 gallon. Could I get some advice on these things? What size do you think I'd need for what I'd be using it for?

[Al Willits]

Generally the larger the gallons the more it cost to run, with that in mind I'd lean towards one of the larger sizes you mentioned, I assume your going electric so I might add a timer to the circuit if you keep somewhat regular hours in the shop.
Other wise find out what the recovery rate is and maybe just turn the water heater on when you just use the shop.
Or...if you just won the lottery or make enough money it doesn't matter, I'd get the 6 gallon unit and just leave it on.:)

Personally I'd lean towards the 4 gallon version, hard to think of when you'd use more than that much at one time.

Al

[Matt Meiser]

I just put in an Aristron (sp?) 4 gal unit. Recovery time is too slow to just turn it on when you want, but they are supposed to be quite efficient. For a sink, I recommend a laundry tub--plenty of room for a bucket or whatever.

[Tom Hamilton]

Hi Rob:

An alternative might be the solution I used: an "Eemax" electric coil water heater.

It has no tank, just heats the water as it passes by the coil. It will raise the temp enough for washing hands, brushes etc., but not enough to make instant coffee. The plumber tapped into an adjacent cold water line for supply. 110v house current supplies the power.

I had a coil failure in the first six months and Eemax replaced the coil without hesitation.

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Eemax is in Oxford, CT, at 203/267-7890. All usual disclaimers apply.

Hope your new project goes well,

Tom, in Houston, with abundant warm water in the shop.

[Rob Bodenschatz]

Matt, that's the one I'm looking at. How long does the water take to get warm? Also, how long does the warm water last? In other words, lets say I were going to be washing a bunch of brushes/paint supplies, would it stay warm for ten minutes or is that too much to expect?

This is a utility sink so I'm not looking for perfection, just want it to be serviceable.

[Rob Bodenschatz]

Thanks for the info, Tom. I'll check it out.

[Jim Becker]

For my shop, I'd use a small electric point of use heater under the sink. May not be the speediest, but it would be fine for the intended use.

[Russ Filtz]

I would check the specs thoroughly if going to one of the "instant on" type coil heaters (tankless models). They typically don't give much temperature rise with a decent water flow, esp. the 110V models. Count on 40-60 degrees rise max. You're not going to get anywhere near a normal tank-based heater level.

To get any really usable temp out of them, you typically need to go to 240V or even higher to make it usable. Here's a link to a chart for temp rise vs. flow that shows amps needed, etc., for one vendor.

http://www.hotwaterheater.com/access.htm

[Matt Meiser]

Rob, you get a couple minutes of hot water max on a faucet with no flow restrictor. I haven't figured out yet how quick it takes to reheat if you run it all the way out, but definitely > 1/2 hour. I turned up the heat to get longer run time of mixed cold/hot water but don't want to go further for safety.

[Rob Bodenschatz]

Half hour. Hmmm. That would take some planning then for when I wanted to use it. Still might be ok for the limited number of times I'll need hot water.

[Matt Meiser]

So far I've found it to be.

Think about it this way: would you use a 5 gallon bucket full of hot water (4gal of hot and 1 of cold?)