Possibillity of Hot Weather Greenhouse

[Tahir Khan]

Have you thought of a lacal MIST FAN ?
I am thinking of making an Orchid house useing one I already have.

Quite right brig sb, the local room cooler works on the same principle
These days the manufacturers which they call as 'Lahori room cooler' are using a synthetic material on the sides of the cooler to cut costs that can be replaced with Khas ki tatti and in this way it will mostly give the same effect..

[rafique]

Following are images of a nusersery at Patoki.
My observations

1. Black color of sheet results good UV filteration added advantage with shade.
2.Larger Mesh Size, resulting good ventilation(felt no suffocation while standing underneath).
3.Angular spread of sheets(High at center and lower from side) , may be for better air flow?

[Farhan Ahmed]

Lovely....what was the temperature outside and in comparison inside?

[M Farooq]

Following are images of a nusersery at Patoki.
My observations

1. Black color of sheet results good UV filteration added advantage with shade.
2.Larger Mesh Size, resulting good ventilation(felt no suffocation while standing underneath).
3.Angular spread of sheets(High at center and lower from side) , may be for better air flow?

That is an amazing structure. How do they cool or regulate the "green" house temperature?

[Farhan Ahmed]

@ Sir Arif...........Mist fan is another good option for temperatures and humidity both.

How to tackle load shedding, i guess Lahore is the most affected city.

[rafique]

How do they cool or regulate the "green" house temperature?

These images are of last month when i visited. At that time there was not any device like fans or air blowers. I am not sure but they were not using any device for artificial venting at that time (economically not feasible for such a large set up).

I think large mesh size of sheet and angles are not hindering the natural air flow.

There might not be strict temp control but there would be difference in temperature aprox. 6-8C underneath+UV protection. Average high temp in this region is around 45-48C in hot months and lowering to around 40C with UV filteration would be quite enough to save plant in those hot months. These are my assumptions.

[M Farooq]

How do they cool or regulate the "green" house temperature?

These images are of last month when i visited. At that time there was not any device like fans or air blowers. I am not sure but they were not using any device for artificial venting at that time (economically not feasible for such a large set up).

I think large mesh size of sheet and angles are not hindering the natural air flow.

There might not be strict temp control but there would be difference in temperature aprox. 6-8C underneath+UV protection. Average high temp in this region is around 45-48C in hot months and lowering to around 40C with UV filteration would be quite enough to save plant in those hot months. These are my assumptions.

Goodness, 45 to 48 oC!! This is good enough to roast any plant. So I guess, the mesh serves to provide dappled shade and lower the UV flux. Interesting design. As I realized now, we are ignoring evaporation effect in high ambient temperature. That could be a major contributor to the internal cooling of this green house. If you recall water in "matti kay bartan" is cool like refrigerated water on super-hot days when hot wind is blowing around.

[Farhan Ahmed]

I think 35 is the temperature we should be looking for

[rafique]

I think 35 is the temperature we should be looking for

I agree with you 100%. But you are talking to ideal state which is not impossible but difficult.
Efforts plus resoures for only May-June(cost and benefits).
In July and Ausgust temperature would be in the range you are saying.

This can be achieved for limited scale but for a lawn it would be quite difficult and for commercial it would be even more difficult.

There are options of automated misting devices which are activated with temperatute/humidity/moistrue/...........but again it is good to get it at for our two harsh months?

For experiment and study we can try it at limited scale with mist fan.

[Farhan Ahmed]

That is agreed that it is 2 or maybe three months....and there is no harm even in stopping the gardening activities fully in these months...BUT

Lets say i have a costly, tropical, less heat resistant perennial which i have got with difficulty from abroad, etc etc.....That plant will die in few days in such a hot weather. For instance Jade Vine. Untill and unless we look for a way to rescue such plants in these two months, we can not attempt them.