How many kW/BTU's aircon for greenhouse?

euser1984

Hi,
Its 1.8 x 3.0 x 1.5 height.

i've been told a 5Kw/18,000BTU system should do the job?

Appreciate any help on this - thank you very much

my3cents

Bit of an overkill most would use a 2kw fan heater.

It depends however what temperature you are trying to maintain in the greenhouse and the temperature outside, frost free is all that many people would aim for.

euser1984

if the greenhouse is too hot the plants won't grow to their potential - so you waste the suns energy. basically, i want to be able to control the environment in the greenhouse

my3cents

euser1984 wrote: »

if the greenhouse is too hot the plants won't grow to their potential - so you waste the suns energy. basically, i want to be able to control the environment in the greenhouse

Open the doors and windows.

Not kidding but most greenhouses don't have enough opening windows so you normally need to buy extra. Automatic vents (when it gets hot they expand) will sort out the window opening for you.

euser1984

it has to be sealed because i will be pumping co2 gas into the greenhouse. plants are capable of using a lot more c02 than the atmosphere provides....3 times in fact for many...

avg 400ppm co2 in the atmosphere....plants can use up to 1500....while the planet gets warmer the plants grow faster

my3cents

euser1984 wrote: »

it has to be sealed because i will be pumping co2 gas into the greenhouse. plants are capable of using a lot more c02 than the atmosphere provides....3 times in fact for many...

avg 400ppm co2 in the atmosphere....plants can use up to 1500....while the planet gets warmer the plants grow faster

Don't forget to talk to them

euser1984

my3cents wrote: »

euser1984 wrote: »

it has to be sealed because i will be pumping co2 gas into the greenhouse. plants are capable of using a lot more c02 than the atmosphere provides....3 times in fact for many...

avg 400ppm co2 in the atmosphere....plants can use up to 1500....while the planet gets warmer the plants grow faster

Don't forget to talk to them

playing music works better and is there all the time

antoinolachtnai

euser1984 wrote: »

playing music works better and is there all the time

I just looked at the irradiance figures and it looks like it might be fine most of the year. But I don’t think it will really keep the place cool on the hottest days of the year.

That might not be a problem though, there aren’t that many really sunny days. But you might be putting the compressor under a lot of strain on those very sunny days. The compressor will be running continuously and with a fair amount of heat applied.

Really you need the advice of someone who fits air con in that type of situation frequently.

euser1984

doesn't matter too much if the air con is turned off on the really hot days

antoinolachtnai

euser1984 wrote: »

doesn't matter too much if the air con is turned off on the really hot days

Then it will get really hot on those days. Like well over 50, if the greenhouse is in the sun at all.

euser1984

antoinolachtnai wrote: »

euser1984 wrote: »

doesn't matter too much if the air con is turned off on the really hot days

Then it will get really hot on those days. Like well over 50, if the greenhouse is in the sun at all.

the plants wont die if they get really hot for a few days - i can manage that. do you mean 50c?