Intellifaucet flow rates?

I'm looking at buying a used Intellifaucet, a K500SS, which specifies a flow rate of 2 to 15 GPM. Is that too high for darkroom use? The commonly-recommended D250 is rated much lower, at 1/4 to 5 GPM.

On the other hand, the K500 specs say it can adjust flow down to 15% of capacity, so doesn't that mean I could lower the output to .3 GPM, anyway? Or am I misunderstanding how that works?

Thanks!

Michael R T said:

the K500 specs say it can adjust flow down to 15% of capacity

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15 * 0.15 = 2.25. Coincidence?

Michael R T said:

I'm looking at buying a used Intellifaucet, a K500SS, which specifies a flow rate of 2 to 15 GPM. Is that too high for darkroom use? The commonly-recommended D250 is rated much lower, at 1/4 to 5 GPM.

On the other hand, the K500 specs say it can adjust flow down to 15% of capacity, so doesn't that mean I could lower the output to .3 GPM, anyway? Or am I misunderstanding how that works?

Thanks!

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just go with the D250. it works great.

RalphLambrecht said:

just go with the D250. it works great.

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+1 Mine just works and is very stable. One caveat; be sure your water pressure is in range of the specs of the valve or if you are over pressure, it can cause leaks and prematurely wear out the seals.

I had to install a whole house water pressure regulator to lower my incoming pressure, but after that, it was happy.

Is the flow rate specification for input or output?
One partially related caution, which is based strictly on memory - which we all know can certainly be faulty!
My recollection is that water temperature control systems work better with hot water sources that use a boiler or tank than ones that use a "hot water on demand" approach. So I would check that as well.

MattKing said:

Is the flow rate specification for input or output?
One partially related caution, which is based strictly on memory - which we all know can certainly be faulty!
My recollection is that water temperature control systems work better with hot water sources that use a boiler or tank than ones that use a "hot water on demand" approach. So I would check that as well.

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Good point. The tankless systems I've used at other houses do seem to require a high enough flow rate to activate. I know because I typically like longer showers but turn the pressure down to minimize my water usage. It was not a fun shower when I visited my parents and ran out of hot water very quickly. I've confirmed this at a friend's house after they installed a gas tankless heater as well.

Another point is, if you live in a climate where your house water becomes warm during the Summer months, a chiller may be required to do precision B&W processing. Mine is around 74.5F at the moment and the valve can't make it any colder!

Kino said:

Another point is, if you live in a climate where your house water becomes warm during the Summer months, a chiller may be required to do precision B&W processing. Mine is around 74.5F at the moment and the valve can't make it any colder!

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That's why I settled on 75F for my processing temps. I can get to that year round without a chiller.

Wow, thanks for all the replies!

koraks said:

15 * 0.15 = 2.25. Coincidence?

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That's an interesting observation. But looking at the specs for other models, the pattern doesn't hold. For the standard K500 (i.e. brass parts rather than stainless steel), the flow rate is listed as 2 to 21 GPM, "selectable from 15 - 100% of capacity." 21 * 0.15 = 3.15. So I'm not sure that the flow range is the same as the selectable range.

Maybe I need to call Mr. Hass again to ask. I feel bad bothering him, considering I'm only looking at secondhand units!

RalphLambrecht said:

just go with the D250. it works great.

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If I can find one used at a decent price, I will! Brand new at $900 is too much for me right now. I am setting up my first darkroom (having used a community one for a few years), so there are a number of expenses to consider, and I still need some key items, like a sink.

A related question about flow range on the D250, though: does it matter if I find an older model that doesn't have the "low flow" capability? It sounds like originally the lowest rate it could handle was 1 GPM, but newer models can run at 1/4 GPM. Does anyone know when this changed? Another question for Mr. Hass, I guess.

Kino said:

+1 Mine just works and is very stable. One caveat; be sure your water pressure is in range of the specs of the valve or if you are over pressure, it can cause leaks and prematurely wear out the seals.

I had to install a whole house water pressure regulator to lower my incoming pressure, but after that, it was happy.

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Thanks for the tip! They all seem to specify an "inlet pressure" of 10 to 100 PSI. I'll ask my plumber about it.

MattKing said:

Is the flow rate specification for input or output?

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I think that is the key question. I had originally interpreted it as the output rate, but given there is a separate adjustment range (15-100%) specified, I started to think it might be the input. Then there is also the inlet pressure specification! There must be some formulas about water pressure and flow and whatnot that explain this; I will consult m'colleague Google.

MattKing said:

My recollection is that water temperature control systems work better with hot water sources that use a boiler or tank than ones that use a "hot water on demand" approach. So I would check that as well.

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Thanks! I believe mine is a tank - the hot line certainly takes a little while to warm up.

Kino said:

Another point is, if you live in a climate where your house water becomes warm during the Summer months, a chiller may be required to do precision B&W processing. Mine is around 74.5F at the moment and the valve can't make it any colder!

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Good point. I'm in New England, so even during the summer I don't think this will become a problem!

Michael R T said:

Good point. I'm in New England, so even during the summer I don't think this will become a problem!

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I’m in southern NH and my tap water is 74 right now. In the summer I think our municipal water is pulled from lakes and reservoirs but other areas mostly pull from wells. That will affect the temp. The good news is this is the time of year it’s the warmest so it’s a good time to measure it so you know for sure.

My experience with the 250 model, has been that if I am running with just a trickle of water it does a lot of “hunting” with the stepper motors going constantly. but even with all its activity, the temp stays pretty close to the setting. I don’t know if that increases wear, or risks a premature failure. I’ve had mine for 10-ish years, it works fine, and I bought it second hand.
More because of the noise, when it starts doing I often increase the flow slightly to let it settle down. I haven’t tried measuring the flow.
You could check with Haas and see if it’s possible to reduce the minimum flow on the 500 by swapping parts. Depending on the asking price of the one you’re looking at, it might still be cost effective vs a new 250 model.

Just an update for anyone interested: I spoke with David Hass, and he said the flow rate specification describes the output from the valve. I'm not sure why the percentage-based "adjustment range" listed doesn't match up in some cases, but he said the flow rate is the range they've tested to work reliably.

Also, while he couldn't tell me what year the low-flow programming was introduced, he said that a 2004-manufactured unit that I was looking at would "probably" have it.

L Gebhardt said:

I’m in southern NH and my tap water is 74 right now. In the summer I think our municipal water is pulled from lakes and reservoirs but other areas mostly pull from wells. That will affect the temp. The good news is this is the time of year it’s the warmest so it’s a good time to measure it so you know for sure.

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As I'm also in southern NH, your post prompted me to check the water temperature, and it was indeed hotter than I had thought just from touch. About 74, just as you said. Have you found any issues with using 75 as your standard processing temp?

Michael R T said:

Just an update for anyone interested: I spoke with David Hass, and he said the flow rate specification describes the output from the valve. I'm not sure why the percentage-based "adjustment range" listed doesn't match up in some cases, but he said the flow rate is the range they've tested to work reliably.

Also, while he couldn't tell me what year the low-flow programming was introduced, he said that a 2004-manufactured unit that I was looking at would "probably" have it.



As I'm also in southern NH, your post prompted me to check the water temperature, and it was indeed hotter than I had thought just from touch. About 74, just as you said. Have you found any issues with using 75 as your standard processing temp?

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I have not found any major issues with using the warmer temp. The minor issues I have encountered are:
1) in the winter my darkroom is more like 68F and for long development in a metal tank the developer will cool off. I usually use a heated Jobo, so it's not much of an issue. When not using the jobo I use a water bath I periodically refill from the Intellifaucet.
2) times get a bit short, and I'm not entirely positive I trust the conversion charts like the ones Ilford puts out. So I tend to determine my own times. I'm testing out D23 1:1 on Delta 100. Jobo times are looking to be 4:20 to 4:50 depending on diffusion vs condenser heads. That doesn't leave a lot of room for N- (contraction) development.

Will Hass let people send in used models for repair/calibration?

Their website says they do, they also provide repair information.

We repair everything we sell. Please contact us for a Return Material Authorization number before sending anything back to us.

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They do, but David Hass did say to me that they have such a manufacturing backlog that anything sent in for service now would be looking at a long wait. On the order of 1-2 months, I believe.

Good to know. These seem like an interesting piece of kit.

Can I ask if it was established whether a hass 500 unit would work for darkroom work?

Ie a 2gpm flow rate?

Can anyone explain what is wrong with this? (Other than paying and wasting water if used in a print washer.

Is there anything else that would stop someone buying a much cheaper second hand 500 rather than a full price 250 unit.

Also has anyone ever used the Batch version of the unit?

I can see real advantages being able to set the quantity of liquid when filling trays.

Also was it established that a 500 unit can be turned down to 15% having read the answers I'm not sure if this was established.

Should i buy a $600 BC500 or $$1600 for the BC250 ???

I think a high flow rateay be worth it?

Michael R T said:

I'm looking at buying a used Intellifaucet, a K500SS, which specifies a flow rate of 2 to 15 GPM. Is that too high for darkroom use? The commonly-recommended D250 is rated much lower, at 1/4 to 5 GPM.

On the other hand, the K500 specs say it can adjust flow down to 15% of capacity, so doesn't that mean I could lower the output to .3 GPM, anyway? Or am I misunderstanding how that works?

Thanks!

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My takeaway is that you should go by the flow rate number. i.e., if it says it does 2 GPM minimum, that is the lowest flow it will reliably work with. Everything I've read says that darkroom work generally uses 1/2 to 2 GPM, max. That's probably why the Intellifaucet D250, which is specifically for darkrooms, covers that range well, with a little extra on either side.

Although I was looking at a K500 model, I ultimately went for a D250 because of the more appropriate flow rate. It cost me $300 shipped, and I have seen a couple others for sale for a similar price just in the month or two that I've been looking. So unless you have a particularly compelling reason, it seems like you could look for a D250 and save yourself some money.

Very kind Michael.

Appreciate the explanation. I'm over in the UK and have been looking for a second hand k250 or BC250 for about 3 years. NOT ONE has come up on eBay, recently I searched Google and found a whole load listed in the US, (of the 500 series) it turns out we don't see your listings this side of the pond, when looking gat ebay directly. (I never knew)

I just thought it would be prudent to get a 500 series while I can, rather than paying for a brand new one at trippple the cost. (Pluss shipping plusses 20% import duty)

If you tell me that they do come up fairly regularly, I can wait another 6 mths in the hope one comes on line.

Not yet installed, I decided to spend a couple of hundred extra to get the K250. I like the idea of setting my own temperatures, versus relying on presets. I also wanted a unit capable of low flow rates.

According to the specifications, this unit is capable of 0.5 gal/min up to 4.2 gal/min.

Hey Neil, did you consider the BC version to allow setting specific water batch sizes?

I'm guessing this could be very useful when developing film or filling trays?

Also why is having a low flow rate so important?

Is this for when connected to a print washer, or is there another reason I haven't figured out?

Jamie A Cowan said:

Also why is having a low flow rate so important?

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Washing film or paper requires very little water/very low flow rates.
If you are forced to use higher flow rates, you waste water and energy.