Greenhouse ventilation

Hi everyone...in about 7wks I get my first greenhouse, a Hercules Trafalgar 6ft x 10ft, it comes with 3 roof vents and 2 louvre vents.

But, from what I have read, the more ventilation you have the better it will be, so I was thinking of adding an extra louvre vent to the order, or maybe even a second door so I can have the front door open and covered with fly screen and then exit through the backdoor.

So, which would be better for ventilation, a 3rd louvre vent or a 2nd door?

 

I have an 8ft x 8ft double door, two roof vents and one louvre vent. We get high winds coming down the Rock Mountains and I get good air flow. I would still put in another roof vent to help heat escape. I do shade the GH everyday during the hottest part of summer.

I think it would depend on the location of your GH but adding another door can't do any harm and I like keeping one end of my GH totally open all summer.

 

3+2 sounds good and if positioned with a little thought you should achieve good air flow.

If you want to add a 3rd louvre ok, but another door ? probably quiet expensive.

Are the vents and louvres using automatic openers ? a real necessity imho.

A fly screen does help keep out the bugs still they still get in via all the other vents.

In high summer you need to add some shading which will keep the temps down, just as important as ventilation.

What are you intending to grow in there ?

Using benches ? having slatted ones help the cool air get around the plants better.

What end of the country are you ? (can you update your profile location box) as that can affect how much ventilation you need .

Seven weeks sounds a long time to order a ghouse ?

 

I have a 6x8 (48 sf floor area) with one automatic vent. I just added a louvre on the opposite side from the vent. Tested it during our one nice day a few weeks ago and the air flow was quite impressive.

I also have fans but they are to keep air moving inside, not for ventilation. And I think because of those, I have no problems with mildew etc.

I would think an extra opening would be overkill. 3 vents and 2 louvres in 60 sf is lots. That would be triple what I have for those extra 12 sq of floor area. Really, lots! And yes, @JWK is correct - a door would take away lots of growing space.

 

Thanks for the advice, Johnny and JWK

Hi Ricky...all vents and louvres will be on automatic openers and I will be making some external shading, green mesh / shade fastened to wooden frames which I can throw up when needed.

I intend to grow Tomatoes to start off with, and then maybe some Peppers and Cucumbers.

One side of the ghouse will have some integral staging, the type on cantilevers that gives you loads of room underneath.

I'm in West Yorkshire, so probably about smack bang in the middle of the UK.

I ordered the ghouse in February, but delayed delivery until mid June, this gives me some time to sort out the chap for the base, which is being done mid May and start to collect all the bits and pieces that Ill be needing.

If 3+2 sounds OK I might not bother with the 3rd louvre, I just thought an extra one would improve ventilation?

 

Thanks Lori...it sounds like 3 vents and 2 louvres is going to be adequate, I think you have just saved me £85

Thanks for the explanation re the sf floor area, it's starting to make sense now

 

Looking at the Hercules site seems they do not do a metal base plinth for it, unlike many others ?

Does tend to make installation a bit easier and add extra height to the eaves.

What kind of base are you having made, just a concrete ring for the frame to sit on, a dwarf wall or a full concrete base / flags ?

If doing a solid concrete base or pointed in flags, one thing I found handy was to have a shallow channel running down the middle so that any excess water and muck can be easily brushed away.

 

Hi JWK...after thinking I'd be too late this year to grow Toms, my local garden center have told me to buy the plants in mid May and grow them on and then transplant them to the ghouse.

Hi Ricky...yes, there is no base plinth, but the Hercules Trafalgar is a High Eave ghouse, so it should be plenty high enough.

The base will be as below, using 600mm x 600mm x 50mm paving slabs

 

Thanks for the advice, Shiney...I have decided to scrap the extra door / extra louvre idea and stick with what the ghouse comes with.

 

The base layout looks fine, provided they are laid onto a properly prepared area / sub base if the site is now just lawn or a soil plot.
Its going to be there for many years so it will settle if the sub base is not sound.

A bit concerned about your water buts being on the same flags, when full its a big weight that will probably settle the flag down after a year or two ..perhaps have those apart from the main base by a few inches so they don't spoil the effect if they do sink a bit.

If this helps, if I was putting up another ghouse I would have these 4 items to hand.
A 5mtr steel tape measure for checking the diagonals.
A pack of plastic spacer for packing where the greenhouse base meets the flags.
A set square 24" or bigger, bought or DIY to ensure the frame sections are square etc. and a reasonably long spirit level for checking its all vertical.

 

Thanks Ricky...the site of the ghouse is going to be leveled first as it's a lawn, then a hardcore base will be laid and compacted and then the ghouse base laid on top.

I like the idea of having the water butt bases slightly apart from the main base, I might even have a couple more flags laid, then I can have 3/4 water butts connected.

Once the base is down I'm not going to touch it for a month or so, then hopefully it will be rock solid for when the ghouse goes up.

Thanks for pictures of the kit, but I'm taking a big short cut and having a ghouse erector put it up for me, that way it should be done right first time.