Would it be possible to use a 120V compact Water Heater For temperature control?

Would it be possible to use a 120V compact Water Heater, like around 6 or 10 gallons, For temperature control? I know that you would probably have to change the thermostat out with one that could go down to 80F, and I know you can do it with mixer taps, but it would be easier if you didn't have mess with adjustments.

The voltage matters not. It’s the power (wattage) that’s important. Too much and the temperature will overshoot its aim point and oscillate for some time before stabilising. Too little power and an inflow of cold water will drop the temperature for a long time.

 

IME a heater power between 150 and 200 watts/gallon or 30 to 40 watts per litre is about right.

 

Efficient mixing _ i.e stirring _ of the water volume is also needed for temperature constancy. Relying on convection turbulence won’t be good enough for process control.

 

What exactly are you trying to achieve Bob? Wash water, for example, doesn’t need a constant high temperature. As long as the water temperature only changes slowly, it can be brought down to ambient for the majority of the wash time.

 

OTOH an immersion water jacket doesn’t usually need as large a volume as 6 to 10 gallons but does need a very responsive thermostat.

Edited May 29, 2017 by rodeo_joe|1

The voltage matters not. It’s the power (wattage) that’s important. Too much and the temperature will overshoot its aim point and oscillate for some time before stabilising. Too little power and an inflow of cold water will drop the temperature for a long time.

 

IME a heater power between 150 and 200 watts/gallon or 30 to 40 watts per litre is about right.

 

Efficient mixing _ i.e stirring _ of the water volume is also needed for temperature constancy. Relying on convection turbulence won’t be good enough for process control.

 

What exactly are you trying to achieve Bob? Wash water, for example, doesn’t need a constant high temperature. As long as the water temperature only changes slowly, it can be brought down to ambient for the majority of the wash time.

 

OTOH an immersion water jacket doesn’t usually need as large a volume as 6 to 10 gallons but does need a very responsive thermostat.

 

Fixing and development,not wash water.

I made a tempering bath using a tapered flower trough - about 9" wide by 24" long by 9" deep. At one end I fitted a 500 watt laboratory heater/stirrer. The whole thing only takes just over 2 gallons of water, since bottles and tank displace quite a volume of water.

 

The lab heater has a built-in thermostat, and apart from making a simple platform to hold it in place, it provides a ready-to-go solution. The heater/stirrer is something like these.

 

If you can't source a used lab heater cheaply, then fish aquarium heaters, pumps and thermostats are an easily found alternative. However, they do need some assembly skills to utilise.

 

Domestic water heaters are generally too powerful and too cumbersome to incorporate in a small water bath. Unless you're heating 3 gallon dip'n'dunk tanks, which it sounds like you might be.

 

This is on fleabay right now.

Edited May 30, 2017 by rodeo_joe|1

Years ago when I did E6, the hot water supply I had was close to 100F, so not good for making a

bath to warm up the chemistry. I used an immersion heater, sold in grocery stores for instant

cups of coffee, to warm up a bowl. I kept one warm bowl, and one cool bowl, so I could quickly

adjust the temperature.

 

I put 240ml in plastic containers, again from grocery stores (like for storing food in the

refrigerator) with lids, one for each chemical step. That allows for fast pour in and out,

and also quick temperature adjustment.

 

I now have a little water heater like you mention (someone was giving it away) but

haven't gotten to use it yet.