Humidity in basement

[Chameleon]

Not sure where to post this but here looks good...

So in my new house I put my sump and frag tank in the basement. Basement is only about 400sq/ft or less total and as you can imagine humidity is a concern. My initial thoughts were to get a dehumidifier, however I have since started leaning towards removing the humid air with some well placed duct fans.
Here are my questions:
In Alabama it is very humid in the summer outside. To prevent a negative pressure from fans blowing out I need air to come in from somewhere.
My options are:
outside
main floor
crawl space adjacent to partial basement

Which option makes the most sense given the high humidity levels outside?
I wanted to use outside air but am concerned it wont eliminate the problem.

What is the best way to put a 6 inch duct through concrete block?

Would it be a good idea to enclose off the portion of the basement with plastic vapor sheet to form kind of a tent eclosure around the frag tank and sump?


I have already covered the floor joist with vapor sheeting mostly to prevent wood particles or the like from falling into the open top tank.

Thanks for any advice

 

[Reef Pets]

You will great a negative pressure throughout your entire house. In the winter you will be pulling warm air from your house and in the summer cool air. A dehumidifier would be the way to go. There would be no negative or positive pressure. Another option would be to cover your sump to avoid evaporation which would lower humidity.

 

[Chris Aldrich]

You're definately thinking along the right lines with the dehumidifier and vent fan. I personally use a combo of both for my basement.

In the actual fish room, I have a vent fan that's originally intended for a bathroom and vents out of the house. It utilizes a sensor/switch which is activated automatically when humidity raises to a certain level. Otherwise you can turn it on manually at which point it runs for around 30 minutes and then turns off. Initially, I thought that length of runtime wouldn't suffice but it has worked quite well. Whenever I'm in the fish room throughout the day, I'll turn the fan on (ranges from 1-3 times per day typically).

For the more humid days of the year, I'll also run a dehumidifer. I don't find this nessesary to run all the time to maintain a humidity level under 60% (what I typically shoot for in the fish room). As you might expect, running one full-time would amount to a decent increase on your electric bill, which is part of the reason I use it only as a supplement to the fan when needed.

 

[Planedoc]

An air conditioner and a dehumidifier are basically the same thing. They compress freon (which makes it hot) and run it through a radiator/cooling fins devise called the condensor to cool it off. Than they drop the pressure to make it super cold and run it through another radiator/cooling fins device that cools the air and removes the moister. The difference between the two is an air conditioner vents the hot air from the condenser outside and a humidifier vents it inside. So a humidifier will remove the moister and heat up your room while an air conditioner will cool the room and remove the moister. They make portable AC unites that can vent to the outside with vinyl dryer type hoses. Another solution is to build a canopy on your sump and frag tanks and installe an inlet and out vent line to the outside. Make the fan blow fresh air in vs sucking out salty air. It will last longer and make sure air from the room is not sucked outside. If you vented the entire area it would get pretty hot in the summer. If your house, including the basement has AC it should do the job all on its own.

 

[Chameleon]

basement does not have ac currently. may have to try a portable ac unit...too bad there are no windows for easy installation

 

[twelvefive]

~!!~LG 10,000 BTU Window Unit~!!~

 

[Chameleon]

~!!~LG 10,000 BTU Window Unit~!!~

thanks mate...so when are you coming by for frags? never heard from you the other day

 

[Chris Aldrich]

Per what I would expect for many [fully underground] basements, mine stays cooler and more constant than the rest of the house year round. So the temp increase from running a dehumidifier is negligible. My basement does have a larger footprint which helps dissipate the effects, though.

At 400 sq/ft, I would expect the warming effect of a humidifier to be more noticeable. In the warmer climate of the southeast, that's probably not as welcomed. So you'd probably be better off with an A/C, as Planedoc suggested.

 

[twelvefive]

thanks mate...so when are you coming by for frags? never heard from you the other day

Wife had other plans for me. What are you doing tomorrow night?

 

[Chameleon]

Wife had other plans for me. What are you doing tomorrow night?

nothing much..just painting and working on installing baseboards and window and door trim. I should be around feel free to come by

 

[Chameleon]

Per what I would expect for many [fully underground] basements, mine stays cooler and more constant than the rest of the house year round. So the temp increase from running a dehumidifier is negligible. My basement does have a larger footprint which helps dissipate the effects, though.

At 400 sq/ft, I would expect the warming effect of a humidifier to be more noticeable. In the warmer climate of the southeast, that's probably not as welcomed. So you'd probably be better off with an A/C, as Planedoc suggested.

Do you tend to have to run it 24/7?

 

[twelvefive]

nothing much..just painting and working on installing baseboards and window and door trim. I should be around feel free to come by

Sounds good, I'll give you a call. Hopefully 530-6ish.

 

[Chris Aldrich]

Do you tend to have to run it 24/7?

During the warmer, more humid times of the year (currently), I usually leave it plugged in 24/7, but it isn't running full-time. I can dial mine in for the humidity threshold it will turn on at and I've found about half (5) is the trick for my unit. I hear it run a handful of times per day, but it kicks off when humidity is back in check. It's noticeable on the electric bill, but not nearly what could be expected if it were running constantly. In the colder, less humid times of the year, I only plug it in as needed.

The thing to remember is the lower the humidity in the room, the higher the rate of evaporation. So if you use the dehumidifier too aggressively all you're doing is exacerbating the problem, racking up your electric bill, and using more water for top-off. I only use it as a supplement when my vent fan isn't able to keep humidity levels in check. You still want humidity in the air, but I try to keep mine below 60% (it typically ranges between 52-60 this time of year).

I also have an inexpensive, digital humidity and temp monitor which is great for keeping an eye on things. I keep it in the fish room because, as you'd expect, that's where the highest humidity levels are found in my basement. Here it is: Purchase the AcuRite Digital Humidity and Temperature Monitor for less at Walmart.com. Save money. Live better.

 

[Chameleon]

During the warmer, more humid times of the year (currently), I usually leave it plugged in 24/7, but it isn't running full-time. I can dial mine in for the humidity threshold it will turn on at and I've found about half (5) is the trick for my unit. I hear it run a handful of times per day, but it kicks off when humidity is back in check. It's noticeable on the electric bill, but not nearly what could be expected if it were running constantly. In the colder, less humid times of the year, I only plug it in as needed.

The thing to remember is the lower the humidity in the room, the higher the rate of evaporation. So if you use the dehumidifier too aggressively all you're doing is exacerbating the problem, racking up your electric bill, and using more water for top-off. I only use it as a supplement when my vent fan isn't able to keep humidity levels in check. You still want humidity in the air, but I try to keep mine below 60% (it typically ranges between 52-60 this time of year).

I also have an inexpensive, digital humidity and temp monitor which is great for keeping an eye on things. I keep it in the fish room because, as you'd expect, that's where the highest humidity levels are found in my basement. Here it is: Purchase the AcuRite Digital Humidity and Temperature Monitor for less at Walmart.com. Save money. Live better.

thanks!
any suggestions on a dehumidifier if I go that route?

 

[Chris Aldrich]

Not a problem, glad to offer some insights.

In terms of a dehumidifier suggestion, I don't have anything in particular to point you towards. Mine is an older model that I keep using because, well...it keeps working. However, if it kicks the bucket, I'll definitely be after an Energy Star certified model. Dehumidifiers are known for being energy-devouring monsters, so they need all the help they can get. As with other Energy Star certified home appliances, they're more energy efficient. I think that's something the 'ole wallet and environment can appreciate. :smile:

 

[Chameleon]

Not a problem, glad to offer some insights.

In terms of a dehumidifier suggestion, I don't have anything in particular to point you towards. Mine is an older model that I keep using because, well...it keeps working. However, if it kicks the bucket, I'll definitely be after an Energy Star certified model. Dehumidifiers are known for being energy-devouring monsters, so they need all the help they can get. As with other Energy Star certified home appliances, they're more energy efficient. I think that's something the 'ole wallet and environment can appreciate. :smile:

thanks!