Computer Controlled Inline Water Heater

[Slothman]

I am helping my girlfriend with an engineering project, and she needs an inline water heater capable of heating water up to 160' F. Not sure of flow rates, but probably using ~1/2" pipe for the inlet and outlet.

Any ideas on how we could build one of these?

We're currently thinking of using hacked aquarium heaters in series in 3" or so pipe, but this seems like it probably won't produce very good results.
Alternatively hacking a commercial electric inline water heater, but I'm not sure if these can produce the temperatures we require.
We have a fairly large budget but cheaper is better.

In terms of controlling it, I am thinking we should use a dimmer controller (http://www.inmojo.com/store/inmojo-mark ... er-module/) and a thermometer downstream.

Thanks

[adafruit_support_bill]

Flow rate is the primary question. Inlet temperature is important too. Take a look through the specs on these units: http://www.rheem.com/products/tankless_ ... s_electric
That will give you some idea of the energy required to achieve the desired temperature rise at a given flow-rate.

[Slothman]

I'm thinking that flow rate should be <1-2 g/m as it is for a forward osmosis project. will standard home water heaters get water to 160' ? Inlet temperature will probably be 50-60', whatever comes out of the tap.

[adafruit_support_bill]

will standard home water heaters get water to 160' ?

Not sure about domestic models. They may have temperature limiters on them. I have seen Japanese units with settings up to 80C (~175F)