Allotment Gardening Advice Help Chat

Growing => Growing in Greenhouses & Polytunnels => Topic started by: businessmonkey9 on May 06, 2020, 13:16

Title: Greenhouse too hot
Post by: businessmonkey9 on May 06, 2020, 13:16

Hi

I have a halls popular with a single roff window which opens when hot. But even with the door open, its over 35c

I am looking into options, but don't want to commit a lot of money for it not to work. (Louvre, shading blinds e.c.t)

any tips to cool the greenhouse down which have worked for people.

Title: Re: Greenhouse too hot
Post by: Plot 1 Problems on May 06, 2020, 13:56

My friend lays a sheet of enviromesh over the roof to difuse the intense sunlight during the summer, secured on with gaffa tape if needed.

Title: Re: Greenhouse too hot
Post by: al78 on May 09, 2020, 18:06

I have the same problem. I put a max min thermometer in there a couple of days ago and despite the door and roof vent open, the temperature peaked at nearly 45C on Friday and reached just over 37C today, with minimums around 21C. Unfortunately my crops in there are not native to Death Valley California, so I have ordered some shade paint to spray on the south facing glazing. With the outside temperature dropping considerably from tomorrow and cloudier weather, the greenhouse temperature should moderate over the coming week.

Title: Re: Greenhouse too hot
Post by: mumofstig on May 09, 2020, 19:15

I throw a length of debris netting over the ridge, from side to side, and use clothes pegs to fix the edges to the eaves gutters.  If it's a very hot summer I'll sometimes even double the netting up, for more shade.

Title: Re: Greenhouse too hot
Post by: Ema on May 19, 2020, 14:34

Having the same problem with my new lean too. It’s got cross ventilation as I put the louvers opposite the door and a roof light. A layer of scaffold netting in white over the front but it’s still regularly over 38.  I’m going to layer up some netting and put on the roof if that doesn’t work I’ll buy some bamboo blinds

Title: Re: Greenhouse too hot
Post by: jezza on May 23, 2020, 22:39

Hello  try something like Cool glass liquid  if available we use to use one  that went clear when it was dull and went white when the sun warmed up, 4 gallon knapsack sprayer did 2 sides of a 110foot greenhouse roof  jezza

Title: Re: Greenhouse too hot
Post by: rowlandwells on May 24, 2020, 19:29

we use like some have said on this site green mesh enviromesh we fix it right down the sides and found it helps keep those UV rays out if it gets to hot i take some glass out of the end of the greenhouse so it gets more air flow then replace when the weather gets cooler

i found that using cool glass was messy and we had to clean it of in the autumn enviromesh is much more cleaner