Indoor growing rack - covered or uncovered?

[Foogoo]

I all, I'm considering expanding my windowsill setup to a rack and possibly adding lights. Here are the two setups I'm thinking of using:

Looks like I can't post URLs. From Harbor Freight, one is titled "4 Tier 5 Ft Greenhouse" and the other is "4-Tier Shelf Rack".

Would the covered or uncovered rack be better for an indoor setup? I'm thinking the covered will keep humidity, but may stop air circulation. Does anyone have a similar setup?

[Leafmite]

Depends on what you are growing. Some orchids need more air circulation than others. I have some orchids on shelves under a clear plastic drop cloth for humidity while other orchids hang freely for maximum air circulation. One orchid, haraella rectrocalla, lives in a little enclosed clear plastaic box with no air circulation at all. Research your orchids before making a choice.

[Foogoo]

Originally Posted by Leafmite

Depends on what you are growing. Some orchids need more air circulation than others. I have some orchids on shelves under a clear plastic drop cloth for humidity while other orchids hang freely for maximum air circulation. One orchid, haraella rectrocalla, lives in a little enclosed clear plastaic box with no air circulation at all. Research your orchids before making a choice.

Good point. Primarily Phals is my plan!

[Ray]

And how is your humidity? If it's a typical low level seen in households, a cover may be a big plus.

[Foogoo]

Originally Posted by Ray

And how is your humidity? If it's a typical low level seen in households, a cover may be a big plus.

I'm in Southern California so I'd say typically the low side. I guess my question is which is more important: humidity or air circulation? Because it seems like it'll be one or the other with or without a cover.

[Leafmite]

Phals should do fine covered.

[naoki]

I agree with Ray and Leafmite, covered is probably a better choice.

I would say that there is almost no disadvantage for enclosed growing space. One possible disadvantage is that if you put a small enclosure exposed to direct sun, it will overheat and kill plants. Also if you start to put artificial lights inside, you need to deal with heat issue. Other than that it is much easier to control the environment (mostly humidity), and you'll be surprised how well orchids respond to high humidity (>70%). I grow mine in 4x2x5' reflective grow tent (probably similar to the indoor greenhouse you are considering, but the grow tent doesn't let light in).

I don't know why you think that indoor greenhouse will cut off the circulation. If you are thinking about CO2 deprivation, it is unlikely that your enclosure is too tight.

There are several function of air circulation, which can be easily provided by putting small fans in the enclosure. It breaks boundary layer of air around the leafs and roots, so it can help gas exchange. Similarly, it also affects the evaporation of water from leaves (transpiration). Then transpiration drives the absorption of water/nutrients from the roots. For this function, you do need slight air movement (especially at night for Phals). But one of the practical functions of air circulation is to control the drying rate of media. I gradually increased the amount of air movement by adding more fans. Finally, some people say that air movement prevents deposition of fungal spores/bacteria on leaves. I'm not completely sure if this is really an issue in indoor enclosure.

[Foogoo]

Thanks for the replies. My concern was that being covered, it might not let the medium dry quick enough and lead to rot. Good point about heat (I'm planning for artificial lighting). I'm hoping to alleviate that by using lower wattage bulbs, since phals are less demanding and they will be in very close proximity.

This is what I'm looking at:
4 Tier 5 Ft. Greenhouse

[Jayfar]

Originally Posted by Foogoo

Thanks for the replies. My concern was that being covered, it might not let the medium dry quick enough and lead to rot. Good point about heat (I'm planning for artificial lighting). I'm hoping to alleviate that by using lower wattage bulbs, since phals are less demanding and they will be in very close proximity.

This is what I'm looking at:
4 Tier 5 Ft. Greenhouse

I have that greenhouse and I use a smallish fan placed on the bottom shelf blowing upward for air circulation.

[naoki]

The lighting could be tricky because the distance between the shelves seems to be pretty short. I guess you are thinking of CFL or household LED bulbs?