View Full Version : Pump setup question

10/03/2017, 08:16 AM
So I have a problem that's not reef related, but does involve pumping water and setting up a sump so I think it's still pretty relevant and you guys might be able to help.

I have a commercial steam humidifier supplying a cleanroom, and part of it's cycle is to drain the water from it's water chamber and refill with fresh water. When it drains, all of the water (about 5 gallons) is drained into a sump pump which pumps it up 2 stories to a drain. The issue is the sump pump is a heavy duty condensation pump like you would have on an AC unit in your home, but even it can't keep up when the system drains 5 gallons at a time. It pumps the water too slow and cannot keep up with the drain rate of the humidifier.

What I'd like to do to fix this is build a sump that can handle the full 5 gallons drained all at once, and a pump that will then drain that 5 gallons more slowly to the drain. I am imagining a 10-12 gallon container with a high head pump and a couple of float valves and a check valve for this, but I'm not sure how to go about plumbing it or wiring it to work. I also don't have any idea where to find a suitable pump with higher head pressures (50' of head or more) that could be used. The flow rate wouldn't have to be very high, maybe 12 gallons/minute or something like that.

If anyone has any advice on how to set the system up, places to look for components to buy, or even specific pumps they'd recommend I'd appreciate it. I'm used to much smaller scale stuff for my reef tank, so i'm at a bit of a loss here.

10/03/2017, 08:38 AM
Check out the Reeflo Power pumps, they definitely have one that will suit your needs.


10/03/2017, 10:09 AM
Why not just get a larger pump and replace the one you have?

10/03/2017, 11:22 AM
Personally, I would just buy a larger purpose-built sump pump, versus trying to rig something yourself in terms of valves/switches/etc.

How often is the 5g volume cycled through? What's the norm for this sort of humidifier installation? Is there really no closer/lower drain than the one that's 50ft of head pressure away?

10/04/2017, 06:41 AM
I would buy a premade sump pump that is purpose built, but cannot find any that are capable and less than $2,000. Seems everything that has the capacity is very expensive. The one I have now cost $300 and it still isn't close to enough. It's more intended for a constant trickle of water, rather than all at once.

https://www.mcmaster.com/#3198k42/=19ny8mi This is the pump I have now. Item#3198K42 from McMaster

It dumps the full 5 gallons once every 3 days or so. The situation with the drain is difficult because it's in the middle of our laboratory, and i have to pump the water up to the ceiling, and then it travels horizontally and then back down to a drain in an adjacent room. I can't have the drain anywhere else because it would cause a tripping hazard.

I imagine the norm for this is to drain straight to a drain without the use of a sump pump, but that's not an option for my situation. Our cleanroom was put together piece by piece, and not contracted out to a single contractor, and the only person in the company that knew about the system left without documenting much.

Vinny Kreyling
10/04/2017, 08:10 AM
How about a 2 sump system?
One on each floor with a suitable pump in each for a 1 story rise.
You don't say what the drain rate of the humidifier is but in my mind a system with 55 gallon barrels & a float valve should do it.

10/04/2017, 08:46 AM
If it's 5 gallons every 3 days, you really don't need much of a flow rate at all. Just a large enough container to hold 5 gallons (how about a 5 gallon bucket?) and just about any pump - maybe even the one you currently have?

If I'm reading your description correctly, the pump is on or near the floor of one room. The plumbing goes straight up in to the ceiling, travels horizontally to another adjacent room, and then goes back down to the floor? So, in reality, there is no net elevation gain - just a lot of friction loss? That's a very different situation than how I'd first read your post where it sounded like there was a huge net gain in elevation.

Also I'm curious who did the install? Is this an application where any codes apply? I'd hate for you to do something based on our advice that caused a compliance issue.

10/04/2017, 08:58 AM
A 2 sump ssystem wouldn't work. What I ment by 2 stories is it is 2 stories high, however there is not a floor above us. It's just a very tall room. Like a manufacturing plant.

The drain rate is probably 10 gallons/minute, dumping the 5 gallons in 30 seconds or so. However, once it dumps that, it stops draining for a while, so if the sump pump is slow, as long as the sump itself can handle a full 5 gallon dump without overflowing, the pump will have time to catch up before another drain cycle.

I found this pump on amazon. seems like a good option I think as it has a high head, and lower flowrate, which is fine if the resivour is large enough.


I'm thinking take that pump, plumb it into a 10-15 gallon resivour with 1 or 2 float switches and set it up to pump in cycles. Say let the resivour fill up a few gallons, then pump it all out at once. I think I'd be fine with the pump working more frequently as well if I can't set it up with a high and low setting. What I mean is only have the pump kick on when the water level reaches 3 gallons, then when it does kick on, drain the tank down to nothing, but then not turn back on again untill it reaches 3 gallons again. That way the pump is not constantly cycling very small amounts of water.

I forgot to mention that the 5 gallons at once is the worse case senario and what is currently causing flooding. The humidifier also does drain constantly at a very slow rate, maybe a gallon every 10-15 minutes.

10/04/2017, 09:17 AM
What you're describing is a latching circuit, which is how most sumps work by default - they don't start until full, and then pump until empty.

A diaphragm pump like you linked would probably work, but that one (and most) are meant to be pressure boosters on a line that's already pressurized. It has a built in pressure switch. You could bypass that if you wanted to use that specific pump. Diaphragm pumps are very good at high pressure, lower flow applications. You don't really need pressure in this case but it wouldn't hurt, and it would solve the head problem.

10/05/2017, 12:17 PM
As far as the pressure switch goes, it really wouldn't do anything in my situaiton as I would never have that much backpressure on the pump, right? I should be able to just plumb the pump in normaly and not worry about the pump having a pressure switch I think.

For the latching circuit, do I need to wire up anything special, or use multiple float valves, or is the tolerance in a normal float valve enough to work as a short range latching circuit already?