Humidity Control?
 

How does everyone with 100+ gallon tanks control the humidity in their houses?

I know there are many options, and I need to choose one.

1. De-humidifier - expensive
2. De-humidifying bags - do they work well? I dont mind hanging bags in my fish room.
3. Fan - would need to create a vent to the outside, or hook into dryer hose which is FAR away
4. Other options?

4. Other options - HRV

I had way too much humidity in my house until I installed an HRV to remove the excess. I typically had over 60% humidity last year, now it is less than 40%. The HRV is more costly to install, but it is much more energy efficient than de-humidifiers or simple exhaust fans. Basically an HRV is an exhaust fan, but it uses a heat exchanger core to warm the incomming air with the heat from the exhaust air thus preventing a lot of wasted heat energy.

My humidity is about 70% right now, and I am adding more tanks so I need to do something fast. I will check out the HRV, where did you get it from?

I run a dehumidifier but it's not enough -- on a cold night my windows will get serious condensation. I evaporate a solid 5g per day amongst all my current tanks so it's a serious issue for me.

I'm now having an HRV put in (just signed the papers this morning in fact). Myself (and a couple others from Calgary) had the work done by Air Pro Heating. I don't know if there's one in Edmonton but I must say I highly highly recommend these guys. Did a fabulous analysis and engineering approach to the amount of turnover required balanced against volume of evaporation, volume of my (eventual) tank room, volume of turnover for the rest of the house, etc.

Actually if you read the specs on HRV's -- I think I would consider getting one even if I didn't have fish tanks.

How/where are you venting to the outside of the house? My fish room is in the basement, I was thinking of renting a giant drill and going through the cement foundation at about the level of the basement windows.

Wouldn't it be easier to cut through the wood and siding just above the concrete? I think if I was doing it that's what I'd do.. I think the current vents in my house are all above the concrete. There's about a foot or two below the ceiling before the concrete foundation. I guess if your basement is really deep that wouldn't be an option but I'm thinking there is likely some wiggle room there.

I didn't know there might be some space there, my basement has a finished roof, but I have some access panels, I will poke my head in there tonight and see what I can see.

I would need a reciprocating saw to do that job, one of the few saws I dont own yet, but could probably buy one for the same price as renting the drill I thought I would need.

I bought my HRV, A Venmar Hepa 3000, from Home Depot along with the installation kit which contains the ducting and vent hood among other parts. It cost about $1000, plus I had to move a few other things in my furnace roiom to clear space for the unit. I did the installation myself, tying it into the existing HVAC ducting rather than installing all new stand alone vent ducts for it. That was not feasable to do given that the house is a two story with a fully finished basement (well almost). I put the vent hood out through the rim joist as Tony suggested. The venmar unit has a combined hood for both exhaust and intake, some units just use two seperate vents which will require you to cut two openings. The entire job took me less than a day to do, but I am fairly proficient at DIY stuff.

If you do decide that you'd rather take the vent out through the concrete wall, you can get a contractor to core the hole for you. I did that for my basement fireplace. It cost me $100 and took the guy less than an hour to do. Just look in the yellow pages under "concrete cutting and coring".

No water in my new tank, but I installed a bathroom fan in the fishroom in the basement. Just went to HD and picked up a dryer vent hood and punched a hole through the rim joist with a 4" hole saw.

If I can do most of my cooling (evap) with the sump, keep the humidity in the FR, the fan plus a de-humidifier I had already have, I'm hoping...


Rona also carries some low cost HVR units, looks like could be a weekend DIY.

Wow $1000 and that is doing the labor yourself, pretty $$$ for me right now.

I think I am going to try and install a bathroom fan, and if need be then add some de-humidifying bags in my fish room and furnace room.

I think I will need one of these dryer vent hoods as well then, and a 4" hole saw, I dont have one that big in my set.

Mark, did you drill from the inside out, or outside in?

HRV is the way to go. Whole house ventilation, unless one has lots of air leaks and the such.

www.lifebreath.com

Great link, thanks!

Humidex

http://www.canreef.com/vbulletin/sho...hlight=humidex

Cheers,
Vic [veng68]

Pilot hole from the inside, holesaw from the outside.

Mark, think I can make a pilot hole through one of my access panels in the roof.

The dryer vent hood goes into the 4" hole from the outside then?

$1000.00 bucks might seem like a lot and it is but not compared to your house. Thats one of your biggest investments and you don't want it rotting and getting mold. I did the HRV like Tony is going to do from Air Pro, it's the way to go.

When you get 200-300+ gallons of open water in your house you have to do some thing or it will be a problem.

Dave

Will a bathroom fan in my fish room vented outside not work well enough?

My house is old, and crappy windows, so there are lots of air leaks in.

You could also look into these products:

www.humidex.ca

Yea, actually any form of ventilation will work. Just need some make up air coming in. Need to be careful of any heating device, like gas furnace or wood burning devices that require fresh air. One does not want negative pressure in the house.

As long as you vent out stale humid air and bring in some dry fresh air, the idea is the same. However in my climate, without the HRV, the heating bill would sky rocket from heating the cold outside winter air.

Do those units have an exchanger core? How do they warm the incoming air?

I'll chime in a bit here since I've been looking into this closely as I plan my 360 installation.

The humidex basically a combination of a vent fan and a humidistat that turns the fan on/off based on humidity. It vents out of the house only, and depends on "leaks" in the house to bring new air in. That would be a concern in a very new, tight house due to negative pressure.

A good vent fan to the exterior attached to a humidistat would do about the same thing. I would guess it would cost less, but require a bit of DIY.

Finally, the last thing I'll mention is that it would be good to control the space where the humidity accumulates. If you can get good containment of the tank and fish room, you have a smaller air volume to deal with.

I was just going to run the bathroom fan 24/7. This winter is crazy warm, so I am not too concerned about the cold air coming in. Next winter might be different.

How effective are de-humidifiers?

For de-humidifiers take a look at sears.com for an idea. They're rated in pints/day and come in differents sizes (up to 70).

Thanks mark, will do.

my dehumidifier works OK. not the greatest. we're having a HRV installed sometime in the near future to deal with the mugginess of the house. the humidity heightens the smell of the pets, it's unbearable some days.

Would an HRV be very portable between houses do you think?

For my 375 I started out with a bathroom fan in the fish room, and found that it was noisier than I liked given its capacity, and salt creep became a problem.

Eventually went with a Vortex inline squirrel cage fan like the attached.

http://http://cgi.ebay.com/ws/eBayIS...tem=7721464970

Much quieter (also due to being placed remotely in the finished basement ceiling) and more powerful. Vented out the wall, with a fresh air supply provided to avoid any negative pressure situations.

I got mine from the local hydroponics store ... they even accepted a charge card :razz:

I bought a bathroom fan and a control to turn the fan on when it reached a certain tempature in the fish room. My plan was a hole out for the fan and a hole in for fresh air. As far as heat I thought the cold air being drawn in the room from the in in hole would keep the temp. down in the fish room.

Then I read more and did the HRV route.

Dave

Caution note.

Before anybody goes punching holes in their houses I thought I would let you know that there is a "minimum distance" to things like air inlets vrs. outlets. You would need to refer to local building control regulations for the exact distances. For example; you don't want a furnace fresh air intake too close to an exhaust outlet. It's like smoking cigerattes:mrgreen:

"Outlets" include clothes drier, furnace, fireplace, washroom and stove exhuast vents.

:smile: That will remove humid air alright. Just remember the negative balance thing. Good thing its warm there. :smile:

One could take an HRV unit with them but depending on how its installed, a lot of structure will be left. It should enhance the value of a house, enough to cover the cost.

De-humidifiers work fine. Just not the most energy efficient things. I depend on one during the summer however, along with AC. Units like HRV,s are not the best in the summer when the outside air is very moist also. However most people with decent central air units seem to have no problems, esp. the ones that have their hoods andso on vented outside. I know several that also vent their large beckett skimmer outside also.

Venting with a bathroom fan will work as long as the humidity level outside is lower than the humidity in your house. Being in Edmonton this is probably your case, but for those of us in more humid locals this simple fix can actually make matters worse. For example, here humidity outside right now is 86%. If I ran a bathroom fan 24/7, I would be exchanging humid indoor air with outdoor air that is even more humid, not a good trade.

The HRV will work the same as a exhaust fan to lower the relative humidity, the HRV just recovers most of the energy used to heat the air in the house before it is exhausted while using no more energy to run. Even here in Calgary the outside humidity is 60% but that is at a temperature of less than 5 degrees. That same air at 20 degrees would be less than 10% relative humidity. Warm air has a greater capacity to hold moisture, Thus, it would contain 10% of the total capacity of water that it could hold before the water condensed out once warmed to room temperature. So even at 86% RH outside, you would gain significant drying of the inside air.

Here is an interesting chart to see just how much change in relative humidity warming the air makes.

http://www.skuttle.com/humid.html

There is nothing close to where I would be punching the hole, so I think I am safe there.

With a HRV , but not with a bathroom fan when the exchange, is, already heated drier air going out for cold, more humid air coming in. I agree a simple bf will help in many situations but not for all.

I'm with Ed on this (my weatherguy training), point to remember it's relative humidity.

Exhausting indoor moist air helps, all basically a HRV does is warm in the incoming air with the out going so you're not dumping (wasting) the heat outside. A bathroom just isn't a efficient way to do it.

The point I was making is that even though the outside air has a higher relative humidity, it actually has less moisture in it. The term relative humidity refers to the amount of moisture relative to the temperature of the air. Cold air can't hold as much moisture as warm air so even though it would seem to be more humid it actually is less so. Calgary can actually reach near to 100% relative humidy in very cold temperatures, but trust me, it is still really freaking dry.

It is irrelavant how you are making the air exchange, the colder outside air still has less moisture. The bathroom fan will work, its just that you'll be pumping all your expensive heat out with it.

Ok I went to the hardware store and got a bathroom fan, the tubing, and a 4" outside vent with a flap so that I dont lose heat when there is no air blowing.

Now, I found a humidistat, but that is to turn a humidifier on, I want the reverse. The only way I know to fix this is by installing a relay switch so that when the humidistat is on, the bathroom fan is off. Is there an easier way though?

I remember someone posted they have a bathroom fan with a humidistat, maybe they can chime in with how they did it?

You technically want a "dehumidistat" not a "humidistat" (they exist, the HRV's come with them).