Tropical Fruit Forum - International Tropical Fruit Growers



Author Topic: Policarbonate greenhouse recomendations  (Read 1160 times)

Plantinyum

  • Member
  • ***
  • Posts: 143
    • Bulgaria , near Sofia city , planting zone 7
    • View Profile
Policarbonate greenhouse recomendations
« on: August 28, 2020, 01:27:30 AM »
Hello , finally I have some more $$$ and will be baying a greenhouse . I only have space for a smaller one like 4 on 3m , and 3m high. Now ,the decision on having one was way easier as we all know ,  compared to that which particular one  to buy 😅😅. There are different thicknesses of metal parts and policarbonate, most of the time the policarbonate sheets are with a thickness of 4 mm ,is that the best I can do ? .I am planning to make it heated in the future and in a perfect world would be happy to be able to grow my tropicals in there all year round. Should I search for a thicker polycarbonate ??
 Now I want  to make it as heat retentive as possible in the winter ,and was thinking if I dig a trench all around the perimeter of the greenhouse and use house isolating styrofoam sheets to manage to cut the coldness that passes thru the ground outside the greenhouse, into the ground inside ? Most of my plants will be potted ,I am not going to be planting them in the ground in the greenhouse,BUT am wondering if a can grow citrus ,feijoa, srawberry guava and such more cold hardy plants planted in the ground inside ?? There are so many variables ,my head will burst from so much posabilities 😅 . As for the heating in winter I am striving for the most cost effective way possible, but still dont want to find my plants frozen due to a burned out wood stove . Thanks for any recomendations and for any other tips for the mounting of the greenhouse, and any other tips are very welcomed. As for the temp I think in winter I dont need more then 15-20 c in the night for not so fragile tropicals ,and citrus I know will handle even subzero temps, correct  me if im wrong .
Thank u all once again ,and greetings from Bulgaria 😅🙋

Jaboticaba45

  • Sr. Member
  • ****
  • Posts: 327
  • Matthew 7:16-18
    • Ooltewah Tennesee, USA zone 7b
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #1 on: August 28, 2020, 08:22:07 AM »
For smaller greenhouses I use plastic covering as it is cheaper. I also use small heater to keep the greenhouse above freezing. This was for a 6x6 ft greenhouse with subtropicals.
chempedak cheena breadnut breadfruit kwai muk pedalai marang jackfruit I love artocarpus-Ryan

Mark in Texas

  • Hero Member
  • *****
  • Posts: 3956
    • Fredericksburg Texas, (central TX), zone 8a
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #2 on: August 28, 2020, 09:02:22 AM »

Plantinyum

  • Member
  • ***
  • Posts: 143
    • Bulgaria , near Sofia city , planting zone 7
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #3 on: August 28, 2020, 03:00:24 PM »
For smaller greenhouses I use plastic covering as it is cheaper. I also use small heater to keep the greenhouse above freezing. This was for a 6x6 ft greenhouse with subtropicals.
tanks, I already have one greenhouse with plastic covering ,but I have read that the nylon does not retain the warmth anywhere as good as policarbonate. Can you say more about your heating eguipment for winter. Also what are your lowest temps in winter, I see you are in zone 7b, Im also in zone 7. What subtropicals were you growing and what temp were you maintaining in the greenhouse, the lolest that did not couse problems ?? Tanks for any guidelines .




Dynaglas palram.

http://tropicalfruitforum.com/index.php?topic=7511.0
thanks ,I did find the bulgarian name of the product, palram is the factory making it, but I cant find the product for sale .....

Plantinyum

  • Member
  • ***
  • Posts: 143
    • Bulgaria , near Sofia city , planting zone 7
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #4 on: August 28, 2020, 03:04:51 PM »
Does anyone have experience with the 4mm thick ,policarbonate, with air between the layers ?

brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #5 on: August 28, 2020, 03:05:06 PM »
Here's the thread from when I built my greenhouse:  http://tropicalfruitforum.com/index.php?topic=18512.75

Insulating the foundation properly is a lot of work.  You not only need to dig a perimeter trench to put foam in, but you need something rigid to affix it to as the earth will move and break it apart.  If the foam boards are all cracked they won't provide much insulation.  If you *do* insulate the foundation and heat the greenhouse yeah you can plant tropicals right in the ground.  I did just that.

If don't feel it is necessary to plant in ground then you can save yourself a ton of time and expense by just using concrete footers to hold the frame and insulate the whole floor so it doesn't leak heat horribly.


brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #6 on: August 28, 2020, 03:08:55 PM »
I've used 6mm and 8mm dual-wall polycarbonate for my greenhouses.  They are much better than single-pane anything, but they still don't insulate much compared to something opaque like foam board or fiberglass (which you can't use for a greenhouse, obviously).  Stopping air infiltration is much more important than the glazing material.  I chose polycarbonate because it looks nice and lasts long.  If I lived in a rural area I would probably do dual-wall inflated polyethylene and replace every couple years.

You will have to heat it, and your heating bills may be expensive unless you have a very cheap heat source.  I have natural gas which is dirt cheap.

Jaboticaba45

  • Sr. Member
  • ****
  • Posts: 327
  • Matthew 7:16-18
    • Ooltewah Tennesee, USA zone 7b
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #7 on: August 28, 2020, 03:11:24 PM »
I've used 6mm and 8mm dual-wall polycarbonate for my greenhouses.  They are much better than single-pane anything, but they still don't insulate much compared to something opaque like foam board or fiberglass (which you can't use for a greenhouse, obviously).  Stopping air infiltration is much more important than the glazing material.  I chose polycarbonate because it looks nice and lasts long.  If I lived in a rural area I would probably do dual-wall inflated polyethylene and replace every couple years.

You will have to heat it, and your heating bills may be expensive unless you have a very cheap heat source.  I have natural gas which is dirt cheap.

To set natural gas up did you need a permit? Also does the gas company charge you money? Dont know if I should use propane or natural gas.
chempedak cheena breadnut breadfruit kwai muk pedalai marang jackfruit I love artocarpus-Ryan

brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #8 on: August 28, 2020, 03:12:33 PM »
Can you say more about your heating eguipment for winter. Also what are your lowest temps in winter, I see you are in zone 7b, Im also in zone 7. What subtropicals were you growing and what temp were you maintaining in the greenhouse, the lolest that did not couse problems ??

If you heat to 55F (???C) you can grow anything.  If you heat to 35F (~2C?) you can grow almost anything.

Jaboticaba45

  • Sr. Member
  • ****
  • Posts: 327
  • Matthew 7:16-18
    • Ooltewah Tennesee, USA zone 7b
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #9 on: August 28, 2020, 03:14:21 PM »
For smaller greenhouses I use plastic covering as it is cheaper. I also use small heater to keep the greenhouse above freezing. This was for a 6x6 ft greenhouse with subtropicals.
tanks, I already have one greenhouse with plastic covering ,but I have read that the nylon does not retain the warmth anywhere as good as policarbonate. Can you say more about your heating eguipment for winter. Also what are your lowest temps in winter, I see you are in zone 7b, Im also in zone 7. What subtropicals were you growing and what temp were you maintaining in the greenhouse, the lolest that did not couse problems ?? Tanks for any guidelines .




Dynaglas palram.

http://tropicalfruitforum.com/index.php?topic=7511.0
thanks ,I did find the bulgarian name of the product, palram is the factory making it, but I cant find the product for sale .....

Platinyum, the subtropicals were citrus and guavas. The lowest temperature they went to was about 28 and were fine. I use a cheap electric heater from local store.
chempedak cheena breadnut breadfruit kwai muk pedalai marang jackfruit I love artocarpus-Ryan

brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #10 on: August 28, 2020, 03:15:32 PM »

To set natural gas up did you need a permit? Also does the gas company charge you money? Dont know if I should use propane or natural gas.

Yeah I had to get a permit.  I didn't have to pay extra to the gas company, only call them and telling them I was adding demand (I guess so they can tell me if they can't supply enough)  Propane is far more expensive than piped natural gas.  Choose natgas if it is available.  If your fuel source is expensive you will gain more from better insulation.  At some point if fuel is expensive enough it probably makes more sense to build a highly-insulated non-glazed structure and use grow lights.  I had dreams of making an automatic removal insulation blanket that would be pulled over the greenhouse at night, but I realized it wasn't worth the effort for me because natural gas is so cheap. 
« Last Edit: August 28, 2020, 03:21:54 PM by brian »

Kevin Jones

  • Hero Member
  • *****
  • Posts: 911
    • Alabama - USA
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #11 on: August 28, 2020, 03:45:34 PM »
Plastic house with small electric heater for me as well... has worked well for years!

Kevin jones


Plantinyum

  • Member
  • ***
  • Posts: 143
    • Bulgaria , near Sofia city , planting zone 7
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #12 on: August 28, 2020, 03:59:30 PM »
Thanks for the replies guys !!

Brian , tomorrow I will take a look  at your tread for the greenhouse, lots of info there I,m sure ! Now as for the ground insolation ,I am planning to plant in the ground only relatively hardier plants, think citrus, which do not need very warm soil temps, was thinking just to make this insolation just to gain some more warmth so the ground does not freeze. I have some really thick styrofoam peaces ,like 25-30 cm thick which I,m thinking will do a good job , but since u say its not so easy to do, and just burying the styrofoam will not work ...do u think if I make a sand layer on both or only on one side of the buried thing , will help with the ground shifting and possibly that way it will have some give in the process of moving dirt. Seems like the ground insolation will be the heaviest rock from the batch 😀

Plantinyum

  • Member
  • ***
  • Posts: 143
    • Bulgaria , near Sofia city , planting zone 7
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #13 on: August 28, 2020, 04:10:21 PM »
Plastic house with small electric heater for me as well... has worked well for years!

Kevin jones
I will be baying a electric heater too, but imagine if the electrisity went out in those -17c nights which I have here almost every winter, that is my main concern. And will have to have a plan b ...which will be either a gas fuel heater or a wood stove or something. Maybe I can use charcoal since it burns very slowly and releases more heat, so I have heard and witnessed .

brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #14 on: August 28, 2020, 05:56:17 PM »
Thanks for the replies guys !!

Brian , tomorrow I will take a look  at your tread for the greenhouse, lots of info there I,m sure ! Now as for the ground insolation ,I am planning to plant in the ground only relatively hardier plants, think citrus, which do not need very warm soil temps, was thinking just to make this insolation just to gain some more warmth so the ground does not freeze. I have some really thick styrofoam peaces ,like 25-30 cm thick which I,m thinking will do a good job , but since u say its not so easy to do, and just burying the styrofoam will not work ...do u think if I make a sand layer on both or only on one side of the buried thing , will help with the ground shifting and possibly that way it will have some give in the process of moving dirt. Seems like the ground insolation will be the heaviest rock from the batch 😀

The reading I have done on insulation says that relatively small gaps in insulation have major effects on its effectiveness.  I am doubtful that you will be able to maintain a continuous insulation envelope using panels end-to-end as you describe.  Water should fill the gaps between the sand and freeze, so I don't think it will prevent heaving.  If you can find some way to firmly attach the seams of the foam panels it might work... look into "H-channels", so they could warp somewhat without breaking free at the seams.

Also, on sunny days even in the middle of winter a greenhouse will become very warm, however the soil might take time to warm up if the previous night was cold.  This imbalance could cause major issues as plant roots would become inactive and unable to feed the leaf activity. 

I am only speculating.  If you want to try you could put your insulation in, leave the greenhouse floor as dirt, and when winter comes use a meat thermometer to test the soil temperature.  If it keeps warm enough try planting into it.  If it is too cold, give up on in-ground planting and instead insulate the floor and use containers.


brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #15 on: August 28, 2020, 05:59:19 PM »
I will be baying a electric heater too, but imagine if the electrisity went out in those -17c nights which I have here almost every winter, that is my main concern. And will have to have a plan b ...which will be either a gas fuel heater or a wood stove or something. Maybe I can use charcoal since it burns very slowly and releases more heat, so I have heard and witnessed .

When I was using electric heaters in my old much smaller greenhouse it was very expensive.  Also, in the US you can only run a single heater per circuit so I had to run a second circuit.  In your country you may be able to pull more heat from a single electrical run, but I bet it will still be expensive.

Johnny Eat Fruit

  • Member
  • ***
  • Posts: 175
    • So. California, Huntington Beach. Zone 10b
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #16 on: August 28, 2020, 08:10:12 PM »
My small 6 X 8' greenhouse. It has two windows on the top. Total cost $425 including lumber.






« Last Edit: August 28, 2020, 08:11:43 PM by Johnny Eat Fruit »

brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #17 on: August 28, 2020, 08:47:54 PM »
In zone 10b, what are you keeping in the greenhouse?

Epicatt2

  • Member
  • ***
  • Posts: 114
  • Starting a fruit forest
    • Tampa, FL / Zone 9b
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #18 on: August 28, 2020, 09:55:59 PM »
Plantinium,

I'd suggest that you might want to consider getting yourself a Mr. Heater.  It runs on lp-gas and a 20# tank will run it continuously on the medium setting for around 38 to 40 hours.  If you watch for them on sale you can pick one up for about twenty bucks.

It's a radiant heater and has near-complete combustion of the lp-gas and no open flame.  I used one for years in my orchid greenhouse and the orchids and tropicals in it never reacted badly to any combustion product. 

One year here (FLA) we had 1718F. overnight for two nights running which happened during an entire week during which the daytime temperature never went over 50F(!) and by setting two Mr. Heaters on MED they kept my 14x20-ft greenhouse at a minimum of 55F. overnight for the entire coldest two nights of the duration.

BTW, I always kept one full 20# tank of lp-gas as a back-up.

OK HTH

Paul M.
==

Johnny Eat Fruit

  • Member
  • ***
  • Posts: 175
    • So. California, Huntington Beach. Zone 10b
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #19 on: August 28, 2020, 09:57:03 PM »
I keep by Start Mangos and Avocado trees for winter. I had my mango trees flushing in January-February earlier in the year. I can more than double the growth rate of my subtropicals with a greenhouse.

brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #20 on: August 28, 2020, 09:58:32 PM »
I used those Mr Heaters in my greenhouse the first winter before I got piped heat into my greenhouse.  They work very well, though it was annoying to have to constantly light them every night and turn off every morning.  And yes, I was running them unvented with no issues.  My carbon monoxide alarm never went off.  I still keep them as a backup in case I lose power/gas.

Plantinyum

  • Member
  • ***
  • Posts: 143
    • Bulgaria , near Sofia city , planting zone 7
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #21 on: August 29, 2020, 12:39:01 AM »
BRIAN , I think I might fix the styrofoam peaces together with window mounting foam, the thing is very  sticky and expands when applied , do you think it will work that way ?? Also our winters in the past few ears seem to be more on the warmer side, last winter the ground did not froze, we had some very cold nights ,but still only on some places in my yard like raised beds the soil froze like 5 cm deep, for a short period of time . Now I know that this does not mean it will be always like that ....

JOHNNY EAT FRUIT , for me a greenhouse is needed mosly in spring and autumn when the temps are lower. In mid summer here we are HOT , so basically its not much needed . Till now, and for sure also this winter I will have my tropicals in the house next to windows cuz there,s no way I will finish the greenhouse fast enough before the frosts. Btw ,your greenhouse rocks !! Is it with polycarbonate or with glass, thought your in zone 10b ,so may not be a good comparison as to my case .


EPICATT2, I found them on amazon, they are expensive, but I,m sure I WIll find the thing way cheaper on other sites, like u suggested . Thought I will not be needing a heater this winter ,cuz my priority is first to build the greenhouse and maybe monitor the temps the first winter to see, what is the amplitude without warming it . Just wanted to hear what u all use as to heating..

Once again thanks for the great  conversation that is happening !!☺
« Last Edit: August 29, 2020, 12:45:42 AM by Plantinyum »

Mark in Texas

  • Hero Member
  • *****
  • Posts: 3956
    • Fredericksburg Texas, (central TX), zone 8a
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #22 on: August 29, 2020, 08:42:11 AM »
Does anyone have experience with the 4mm thick ,policarbonate, with air between the layers ?

In research yes.  You'll get good insulation value with sharply reduced light transmission.

Nothing's easy.  :D

Plantinyum

  • Member
  • ***
  • Posts: 143
    • Bulgaria , near Sofia city , planting zone 7
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #23 on: August 29, 2020, 11:03:15 AM »
Does anyone have experience with the 4mm thick ,policarbonate, with air between the layers ?

In research yes.  You'll get good insulation value with sharply reduced light transmission.

Nothing's easy.  :D

hahah was hoping that thing with the light, that I also heard was not true ... yet again people succeed growing plants in such environment so ....guess should be fine ? 😀

brian

  • Hero Member
  • *****
  • Posts: 1470
    • Pennsylvania (zone 6)
    • View Profile
Re: Policarbonate greenhouse recomendations
« Reply #24 on: August 29, 2020, 11:32:32 AM »
I thought 4mm light transmission was very high, like 95%?  I am using 6mm which is less, and previously used 8mm which is like 80-85% with good results.  I think you'll be fine

 

Copyright © Tropical Fruit Forum - International Tropical Fruit Growers