I've been using a "laundry tub" pump for a few years now with no problems. When I asked around this was what was recommended.
Over the years I've had good luck purchasing items from Northern Tools (no connection except as a customer). Never had a need for a sump pump - but here's a link to their selection:
How much lift and how many gallons? Dan
Originally Posted by brYan
My first reaction is to be a bit surprised that the upper end temperature is so low. Obviously, the temperature at which the pump will fail has to be somewhatly higher than 70 deg F (the manufacturer has to have some margin between the rating he applies to the pump and the actual failure point), but we have no way of knowing what that margin is. As a "sump pump", the water temperature in the intended application will almost certainly be below 70 deg F.
Originally Posted by brYan
I have a couple of sump pumps that I used as lift pumps - one for gray water from my darkroom, and one for the drain from a sink in my basement workshop. Frankly, the last pump that I bought (about two years ago) came in what struck me as an amazingly cheesy plastic housing. The older pump is also in a plastic housing, but it appears to be a more robust "engineered plastic" than the newer pump.
I have never measured the actual temperature of the water that I put through my darkroom lift pump. I capture the gray water in a reservoir (actually, a large Rubbermaid bini), and use a float switch to start the pump when the level reaches a critical point. I only do black and white, and with the exception of some toning, everthing is done at or near "room temperature". So I suspect that the actual temperature of the gray water in the reservoir never actually exceeds 70 deg F.
My basement was first finished to include a bathroom. We cut a hole into the basement floor and set a 20 gal. abs plastic holding well; into which we piped the potty and the sink. It uses a small grinder typer sewerage pump to send the waste water up to the septic tank.
When I constructed my darkroom, directly adjacent to the bathroom, I simply ran a drain pipe to holding well from the sink. Works like a charm...
So the short answer is...either will propbably work for you. I don't think the water temps that you'll be using in your dark room are hot enough to cause stress on the sump.....jmo.
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I use a sump pump to raise the sink's waste 2 meters above the darkroom floor into the sewage pipe.
When I was in the purchase, I was told to carefully check for one whit extended corrosion resistance because the pump has it's component submerged all the time and whe dump acid and.or basic effluents. Some, like the Ilfochrome or E6 stuff are corrosive.
So the main concern here is corrosion, not temperature. Sump pump not able to manage 70 °C water are cheap chinese product better avoided into a darkroom. What about a pump failre when you dump the 50 Liters+ of your washer ? What about a pump failure splashing the floor with a mix of DEV, Fix and stop bath or selenium toner ???
The guy selling sewage pump specifically stated that their models where unsuitable because gaskets won't handle acid waste. (as it was a French model, in France, your milleage may vary) And the manufacturer of the sump pump I bought said to me that, even if made of stainless steel, I'd better rinse with plain water AFTER dumping acid waste, in order to have the pump staying immersed into non acidic waste...
Hope this helps !
George, thanks for the link.
I have some questions if I may... What is the general way of installing one of these pumps if I were to install a darkroom sink?. Do you need to punch a hole in the concrete to house it or will a large plastic tub do? No solids will be dumped.
I will be attaching to a higher drain pipe (My darkroom is in the basement). Another concern is with it being able to keep up and not overflow. Any recomendations for pumping rates or models would be apreciated.
I hope I am not diverting from the original poster's questions.
As noted above, I have two, one in the darkroom and one for a sink in my workshop. In each case I have a reservoir under the sink to catch and hold the graywater before pumping it up to the household sanitary drain - which runs just below the basement ceiling. In both cases, the units are the fully submirsable design with a float switch that pivots at the end of a short length of cable.
The question of reservoir volume is important. You are concerned about both depth and the cross-section dimensions. In the darkroom in our former home, I used a 5 gallon plastic pail (from driveway sealer). The depth of that pail was just barely sufficient - the float switch on the pump caused it to start when the liquid level was only about a 1/2 inch from the top of the pail. When we moved to the new place, I shopped around for a container that was deeper than the driveway sealer pail. The Rubbermaid bin in the darkroom is about 2" deeper, so there is about 2" of "freeboard" when the pump starts. Incidentally, an advantage of the Rubbermaid bin option is that they come with lids. On the other hand, the Rubbermaid bin is rectangular, and for mechanical reasons, round containers are stronger when it comes to holding fluids. As a result, there is a pronounced bulge when the liquid level nears the point when the float switch kicks in.
For the shop, I chose a round laundry tub. It has 3-4" of freeboard, but it doesn't have a cover.
In my current setup, I have never had a problem with the float switch not starting the pump when the reservoir was full. That was not the case in the former arrangement using a plastic driveway sealer pail. What happened was that the float switch would touch the side of the pail, previent it from freely following the liquid level. I had a couple of instances when the pail overflowed - what a mess! When I chose the new reservoirs, I also made sure that they were large enough to not interfere with the float.
I will say, however, that in both instances I can visually check the liquid level, and subconsciously I do that frequently to make sure that the reservoir doesn't overflow.
I would be very hesitant about penetrating the concrete floor of the basement. Around here, there is a concern about the subsurface water level and wet basements, and poking a hole in the floor will aggravate that problem. In fact, when I built my darkroom, I used construction adhesive to attach the sole plates for the walls to the floor rather than cement nails to avoid any form of penetration of the floor.
There is one other option that you may have. If your home has a basement sump, and if it's convenient to the darkroom space, you could drain into the sump, and then rely on your sump pump to remove the graywater along with other seepage into the sump. Before taking that option, it would probably be wise to make sure that your normal seasonal flow into the sump can be readily handled by the sump pump - you don't want to be putting more volume into the sump than the pump can handle.
And to Georges' point, I think the key to both the temperature problem and the problem with darkroom chemicals attacking the pump is to make sure that there is enough volumn to dilute undesirable elements in the darkroom effluent.
One other point: for safety reasons I have both pumps on electrical circuits with GFI protection. Last year, I noticed that the darkroom pump (which is about 10 years old at this point) was tripping it's GFI. I suspect that a gasket is leaking and that I will need to replace the pump sometime soon. The pump on the shop sink is much newer, purchased whenI set up the shop when we moved three years ago, and I've already had to replace that pump once. As noted above, the newer pump has a much cheaper feel than the old darkroom pump, so either they have been cost-reduced or else the first unit I purchsed for the shop had an "infant mortality" failure. Having them on a GFI circuit provides a sense of security, but it also means that the ability to visually check the liquid level occasionally is important since you never know if the circuit has tripped.
Incidentally, sump pumps come in two designs - there are also models in which the motor is on a pedestile, and the float switch rides vertically on a rod. If you have enough clearance above the reservoir, these may be preferable to the fully submirsable design.
Originally Posted by JHannon
My basement darkroom sink drains into a big rubbermaid type tub. The sump pump is in the tub. I have two holes in the tub lid, one for the sink drain going in and one for the waste water that the sump pumps out. I have a check valve in the 'out' line. The waste water is pumped up as high as I could get it in the darkroom and then falls towards the sewage connection.
To size the pump you need, you'll need to figure out how much lift you'll have. This is how many feet of piping from the pump to the point where there is natural fall/slope towards the sewage connection. In my case, the lift is only about 6 feet from the sump pump to the darkoorm ceiling, where the pipe turns and falls/slopes the rest of the way out.
You'll also want to figure how many gallons per minute you'll need to pump out. I have the float on my pump set so that the tub fills about 3/4 of the way before the pump kicks in. It takes about 5 or 10 seconds for the pump to pump it down and then shut off again.
I think I bought something about like this:
Louie and Matt, Thanks for your reply.
Originally Posted by Monophoto
This is also my concern and I plan on doing the same with construction adhesive. I have enough leaks without starting new ones
My drain to the laundry tub is 8 feet away and only 2 feet off the floor. I am hoping I can tap into this.