Goin' green in the darkroom!
Cautionary tale. After ten years of the wife turning the gas-powered hot water heater up to that notch just past VERY HOT (yep, ours goes to 11!)
it finally crapped the bed in grand fashion. Much to my delight, because now we can get one of those tankless heaters. No more watching my wash temperatures bounce between 59f and 95f in a matter of seconds when someone wants to take a bath!
Developed my first films today. Turned the hot and cold knobs, figuring it would warm up pretty quick, then adjust from there.
Five minutes later, no warm water. Shut the cold off. Five more minutes, no warm water. Me very confused. I just used hot water half an hour ago in the kitchen. Go to the kitchen, and immediately there is hot water.
Turns out that my darkroom tap doesn't draw water fast enough to activate the heater. So, here in the land of unintended consequences, in order to develop and wash films using my government subsidized green tankless water heater, I need a hot water tap turned on somewhere else in the house. Who'da thunk it?
Anybody with an idea or resource for solving this problem that doesn't involve plumbers, I'd love to hear about it.
Most all of the tankless heaters work on a flow rate, and some times it is just to low to work. I looked at this for my new darkroom/studio. What did we do a small electric unit (we have an all electric house). It work just fine. In the winter the ground is at 20 to 30 degrees and the cold water is just that cold!
Ok fixing the problem you may need to have a hot water holding tank so you can control temps.
I had this problem when I tried to use a tankless heater in the darkroom; you also have the issue of the high electrical load, my unit was 9.5 kW.
Yes..... Do your own plumbing!
Originally Posted by Rich Ullsmith
Perhaps one of the pumps which is used to increase the flow rate for showers. Do you have those in the US? (the pumps, not showers!).
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.
For films use the Ilford method of soak and dump. I use this for both film and paper. I use more water changes than they recommend. The results are great.
Your experience is precisely why I won't get one of these heaters. I experienced one at my parents' house. I usually take a long low flow shower, turning up the flow just for the final rinse. Their water heater would cycle between hot and cold at anything other than full water flow.
My next heater will be one of the heat pump units. I'll get free dehumidification in the summer which should cut the electric bill greatly. My gas heater costs almost as much to run as the prior electric one, so the heat pump should save at bit.
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I have a tankless water heater, and hot water for the darkroom is a PITA, for the reasons mentioned. I worked around it to a degree by running the hot water full blast until it got the pipes between me and the water heater full of warmed water, then switched to the tempered water for the film or print washer, or whatever. Another possibility is to do laundry or run the dishwasher or something while you're doing your darkroom thing.
The real answer which is what I did a few months ago is to install a small point of use water heater under the sink, plumbed into the hot water. Not quite as green, but functional, they heat quickly, so you could turn it off when you won't be doing DR stuff for a while.
I've also seen recommendations to expand from that and install something like a 10 gallon tank water heater on the hot water line following the tankless. You don't spend the money to keep 30+ gallons hot, but it bridges the gaps and provides hot water in the low flow situations.
There are many things I really like about our tankless heater, but this is one of the weak areas.
Go ahead and replace the house tank with whatever you want, and put a 4 or 5 gallon point of use electric tank in the darkroom for your own use. They are small enough to fit under the counter and for what little bit you use, will work out perfectly.
I had this problem in my darkroom, after I installed a tankless water heater. I solved it by replacing it with a regular tank water heater.
Some tankless water heaters allow you to dial down the hot water temp, such that you could use more volume running through the heater to get the temperature you need without the heater shutting off.
I've never been able to make a tankless heater work in the darkroom. Modern archival washers work with flow rates far below the tankless heater initiation point. Nothing beats a nice hot water reservoir.
Install an 80 gal. GE Smart electric water heater. If possible partition the hot water lines in your home so the tankless supplies the baths and other high demand areas like dishwasher and laundry.
Originally Posted by Rich Ullsmith
The electric smart water heaters don't heat the water all the time but have 2 5000W elements (only one turns on at a time) to produce a constant source of hot water when demanded by the flow rate of cold water entering the heater. We don't miss our gas heater at all. It does require a dedicated 30AMP circuit.
I was never sold on the tankless systems for a number of reasons. I also recommend a whole house filter and an incoming filter for the hot water heater. It's amazing to see how dirty tap water is. I live in a fairly young home about 2 miles away from a new 4 billion (yes that's billion with a B) dollar county water processing plant. In my darkroom I have additional filtration on the hot and cold incoming and a chlorine filter on the outgoing water. This really helps reduce crude on film after washing.
Last edited by donbga; 07-17-2010 at 07:11 PM. Click to view previous post history.