Venting to outside

[Swingline77]

I've decided to vent my tank to the outside. I'm going to fully encase the top of the tank in epoxy-coated plywood. I'll have a little "tower" with a removable lid that the skimmer can extend into from below. There are two ways to vent, and I'm not sure which would be best.

The first way would be to have a hose come in from outside, go through the plywood, and hook to the air intake of the skimmer. The exhaust hose could be mounted anywhere in the plywood, and lead back outside.

I've read of others doing things more-or-less this way, but it seems there are some potential issues in my case, considering distances involved. One is that the longer the hoses are, the greater the pressure that must be overcome in order for air to circulate. If one hose were hooked up to the skimmer, I have no idea how well the venturi would pull air from four feet away. I also don't know if this would harm the skimmer motor, though my gut feeling is that this arrangement would put no additional strain on the motor, since if the negative pressure becomes too much to overcome, the venturi would simply stop working.

The second problem with this method is that I wonder if I'd need to increase the diameter of either the intake or the exhaust tube to deal with pressure issues.

The second method is not to hook the air to the skimmer, but to instead vent air to and from the underside of the plywood via an inline fan. The disadvantage here is that immediately, I'm looking at a noisier and more complicated solution. If I go this route, I'd be forced to use thicker tubing/ducting. At least in the first scenario, I can potentially get away with hose that's 1" OD. In the second, I'd probably be looking at 3" ducting at a minimum.

So, I guess all this comes down to whether the skimmer could really not only pull air from 4 ft away through a 1/4" ID tube, but whether air could vent well through such a tube over 4 ft as well. Any ideas? Thanks.

 

[Johniejumbo]

I get the problem you have. Unfortunately I don’t have much knowledge on pressures and vacuums. I personally think 4 ft is an inconsequential distance for a skimmer to pull from. As long as the tube is clear. But if I were asking. I would post again if no one else has better advice. Tough topic for a layman like me

 

[Mark Bianco]

I've decided to vent my tank to the outside. I'm going to fully encase the top of the tank in epoxy-coated plywood. I'll have a little "tower" with a removable lid that the skimmer can extend into from below. There are two ways to vent, and I'm not sure which would be best.

So, I guess all this comes down to whether the skimmer could really not only pull air from 4 ft away through a 1/4" ID tube, but whether air could vent well through such a tube over 4 ft as well. Any ideas? Thanks.

I am no expert but perhaps I can share some things I know to be facts when it comes to skimmers and flow of gases ( yes air is a gas).

I work with plasma systems and after the gases pass thru the mixing then the metering counsel they are supplied and vented to and from the torch by 1/4" tubing. I know for a fact that changing the length of any of tubing results in a poor quality cut. In other words manufacturers design products to operate a certain way and changing that could have a negative outcome. Skimmers are fussy!!!

I had my sump in the basement in an enclosed room I insulated it and ran a small heater in the winter to keep the temperature constant. Long story short the heater failed and the difference in air temp effected the way the skimmer worked and it overflowed. How much a temperature change will you see? It may or not make a difference.

Is your intent to enclose to remove the smell? If it is then there is two ways one very inexpensive and one costly.

The first would be to throw a bag of carbon in the flow system somewhere this works surprising well.
The second is to enclose the system like you are talking except make some vents on top of the tank lid and in the face of the lid then run a small exhaust fan to the outside. This will add to your heating / cooling bill.

As stated I am no expert just providing information from my experiences in the hobby.

HTH
Mark

 

[ca1ore]

If extending the length of the skimmer airline, I think it is always a good idea to upsize the tubing.

 

[Swingline77]

Thanks for the replies. For now, I think I'll just use oversized tubing hooked up to the skimmer. If this is insufficient, I can always add something more complex later.