Plumbing for Water Temp Control + Darkroom Plans

[Rob Vinnedge]

Speaking of in-line water heaters, I just ran across the Rinnai units that are being promoted in the Seattle area as energy efficient alternatives to the traditional tank (gas and electric). A contractor friend of mine swears that a dishwasher, washing machine, and shower running simultaneously will not cause a hot water shortage. We plan to have two installed in our studios and one in our home.

see www.rinnai.us

[Nathan Potter]

OK, in my darkroom I develop color chromes and do Ilfochrome prints (yes still). So I need some pretty fine temp. control for reproducibility. Even in B&W when I make TMax masks for the Ilfochrome work I need to hit density value pretty exactly. So I want +/_ 0.5 degrees F.

For fall, spring and winter in Austin the incoming city water falls below my processing temps so all I need to do is heat the cold water a bit. To save money when I moved here I bought a couple of 500W light dimmer units; a couple of 500W water heater elements and some PVC pipe and fittings - all at Home Depot. I then simply used a section of PVC pipe with proper NPT end fittings that would accept the water heating elements and wired the elements to the dimmer controls. The water heating elements inside the 2 inch diameter PVC pipe is a bit scary but I make sure the water is flowing prior to turning on the heater power. Since the city water temp. is very stable I can dial in the heater to raise temp. to exactly the desired temperature. This is the arrangement I currently use until I spend more money on something fancier. Works just great.

BTW the whole house in line water heaters are great but need a gas burner to work fast and efficiently. I'm not sure you can even buy an electric in line heater.

Nate Potter, Austin TX.

[blevblev]

I use a Leedal temperature control unit which is mounted on a board and also has a filter. It has attachments for hot and cold, a mixing valve (2 in 1 out) with thermometer and the filter is on the output side. See:

http://www.calumetphoto.com/item/AY0434/

[Rob Vinnedge]

OK, in my darkroom I develop color chromes and do Ilfochrome prints (yes still). So I need some pretty fine temp. control for reproducibility. Even in B&W when I make TMax masks for the Ilfochrome work I need to hit density value pretty exactly. So I want +/_ 0.5 degrees F.

For fall, spring and winter in Austin the incoming city water falls below my processing temps so all I need to do is heat the cold water a bit. To save money when I moved here I bought a couple of 500W light dimmer units; a couple of 500W water heater elements and some PVC pipe and fittings - all at Home Depot. I then simply used a section of PVC pipe with proper NPT end fittings that would accept the water heating elements and wired the elements to the dimmer controls. The water heating elements inside the 2 inch diameter PVC pipe is a bit scary but I make sure the water is flowing prior to turning on the heater power. Since the city water temp. is very stable I can dial in the heater to raise temp. to exactly the desired temperature. This is the arrangement I currently use until I spend more money on something fancier. Works just great.

BTW the whole house in line water heaters are great but need a gas burner to work fast and efficiently. I'm not sure you can even buy an electric in line heater.

Nate Potter, Austin TX.

Nate,

I ran across several models of Bosch in line water heaters at Lowe's the other day and discovered that one of them is, indeed, electric.

[robert amsden]

A tankless water heater will not work for darkroom because it need a large flow of water to turn on.

[Turner Reich]

No one mentioned the older Kodak control units, I have one and it works fine, the temp is easy to keep steady but the water needs to run all of the time. It's a waste of water and if I add a hand washing take off the vacuum breaker goes off and I have to restart the unit.

I would like a water control unit that was on demand at the proper preset temperature. I have a 1" cold water feed to a 40 gallon water heater that is used only in my darkroom, I would have a controlled temperature for chemistry and a hand washing temperature drop with a hot and cold in a deep sink. I have the steel hard rubber chemical deep sink, two in fact, along with the main sink but haven't gotten around to replacing the Kodak unit. I have Powers unit but never tried it out, I heard that the inside therm needs replacing every year or two, that's too much maintenance. I"ll have to look at the Intelli-faucet and see if it needs to run all of the time. I have a control manifold from a lab set up in chrome that would be great to install.

[Clay Turtle]

A tankless water heater will not work for darkroom because it need a large flow of water to turn on.

Might be that flow rate is major factor in their use but I have seen individual instant hot water units [under the sink models, bottled water coolers, etc.] which operate with small flow rates.

[BigSteveG]

Haven't read the entire thread, but the Leedal company in Chicago still p
roduces mixing uints and filtration systems. I happened to get lucky and bought NOS setup from a photogrpaher who never installed it.

[Drew Wiley]

A recirculating thermoregulator will provide much more consistent and accurate temp control than any kind of mixing valve. An insulted outer bath and a stainless steel inner
are the ticket. I had an Accutemp that was wonderful for about 20 years until it burned out. LSS offers something similar for around $1200 which is efficient in the correct range, and accurate to about 1/10F.