Are computer fans enough for air movement in a non-enclosed area? - Orchid Board

camille1585 · #1 01-09-2019, 04:39 PM

I guess the thread title says it all.

I never had much mold issues with my orchids, until I acquired some more Dens a year ago. I have lots of issues with spotting and rotting leaves. I know that Dens like good air movement, and my racks don't get much. My plan was to wire up an old computer fan at the end of each shelf and put them on a timer to turn on at regular intervals during the day. However, while computer fans are more than enough for a terrarium set-up, do I need something more powerful for an unenclosed living room set up?

rbarata · #2 01-09-2019, 05:15 PM

It depends on how far it is from the plants...if their leaves move gently, that's enough.

wisdomseeker · #3 01-09-2019, 05:25 PM

You can certainly try out a computer fan, but I don't think it will provide the results you are looking for. Another option might be a small a/c fan like the one in the photo below. It has a small profile (6 inch diameter) and pushes out a fair amount of air.

I use these above my aquariums in the summer when temperatures start getting extreme. These fans were purchased at Walmart for about $8 US. Easy to mount and connect to a timer. Don't know what your a/c voltage is where you reside, but residential a/c in the 'States' is usually around 120v (what the fans are manufactured to run off). Most computer fans are d/c (usually 12v).

Paphluvr · #4 01-09-2019, 07:53 PM

What size computer fan were you thinking about. I think a lot of computer fans are only a bit over 5cm. I would think you would want one more on the order of 10cm or more but it would actually depend on the m³/min. I am also a windowsill grower and use a fan like Wisdomseeker. It has two speeds and moves a decent amount of air. I think you should be able to find something similar in Europe. Is the voltage in the Netherlands 220v/50hz?

estación seca · #5 01-09-2019, 08:36 PM

Could it be they are too far outside the temperature/humidity range they might prefer?

camille1585 · #6 01-10-2019, 05:50 AM

I decided to go with computer fans for now because I wanted a low cost option (can get everything at a second hand shop), and something compact enough that I could mount to the shelves directly. There is no space on/near them to put a small stand-alone fan.

I have one old computer fan laying around, so I can always give it a try. It’s a ‘large’ fan, about 12cm diameter. But if the general consensus is that it’s probably not enough, I’m not sure what else would fit in my space. As the stands are in the living room I try to keep the grow area esthetically pleasing.

As to the conditions not being ideal, it could be. I only grow orchids that do well in intermediate conditions (my grow area is generally in the range of 18-24°C), and most thrive. However this summer we had an exceptionally long and hot heat wave where it was 35°C in my living room for close to 3 weeks, and over 30°C for several more weeks. (Dutch heat waves usually last a couple days at most). I was already getting spotting and rot on my Dens well before that. When I first tried Dens 2-3 years ago, my Den Micro Chip became heavily spotted, dropped all the leaves, and never recovered. Humidity is in the 40-70% range, depending on the season and weather.

katrina · #7 01-10-2019, 07:23 AM

If the computer fans don't work out, check into what they call "personal desk fans" or "clip on fans". They can be clipped onto the shelf so no floor space needed. I don't have any in use right now but have used them in the past and they worked great.

Ray · #8 01-10-2019, 09:31 AM

No timer. They should be operated constantly.

The idea is gently moving, tumbling air, not a hurricane.

camille1585 · #9 01-10-2019, 02:37 PM

Quote:

Originally Posted by katrina

If the computer fans don't work out, check into what they call "personal desk fans" or "clip on fans". They can be clipped onto the shelf so no floor space needed. I don't have any in use right now but have used them in the past and they worked great.

Thanks for the suggestion, I never heard of those, but I'm sure I can buy them online here!

Quote:

Originally Posted by Ray

The idea is gently moving, tumbling air, not a hurricane.

I was already aware that gently moving air is all that's necessary, but I was concerned that PC fans wouldn't be enough to do even that, when you consider that they provide exactly that in terrariums, which is a far smaller volume of air to move around.

orchidsarefun · #10 01-10-2019, 02:57 PM

I've wondered about air circulation in a room. For example if you have plants under lights in a small corner of the basement - say 5% of floor space - is there sufficient air circulation in that grow space? Plus with hot air rising and cold air settling. People and pets moving. Laundry going. I've never used fans, and haven't had the necessity too, indoors.