hot or cold water to RO/DI unit?

[jacksonpt]

I don't have the option of hooking into a faucet for luke warm water, so am I better off hooking into the hot water line or the cold water line?

 

[zman1]

Cold

 

[chipmaker]

I would be very surprised if the instructioons that came with the unit did not specifically state what the operating temp was, and its always gonna be cold, not hot. HOt or even water that is just a tad bit too warm will ruin a membrane. Read the instructions. As fast as an RODI is using water thats warm with the pretense it will preheat it for addition to a tank is incorrect as odds are it will cool down to room temp pretty quick anyhow until yu get a gal or two or more made. Same for using what is specified, the cold will warm up to room probably just as quick as the hot or warm would cool down. IN either case a submersible or hob type heater will fix the temp variation.

 

[fender]

Also hot water will have alot more junk in it. Hotwater heaters have a tendency to collect garbage over time and release it.