So, how much heat will your greenhouse need during winter? This is a question you have to first answer before introducing a heater into your structure….and that’s where a greenhouse heater calculator comes in.
The secret here lies in figuring out the number of BTUs required to sufficiently heat the space.
As you may know, these calculations are so crucial.
Otherwise, chances of installing an improperly sized heating device are high.
And you know what that means: potentially big losses in harvest and damaged plants
To begin our greenhouse heating calculations, we will need some basic data:
Well, these calculations are pretty simple.
Here are the rest of the steps
Start by capturing the following data
Now find your green house’s surface area (S.A.) as follows:
Let’s assume your answer comes to 600 square feet.
The next step in this greenhouse heating calculation is to find what we call temperature differences (for lack of a better word)
Here you take the ideal temperature you need in your greenhouse then subtract from this the lowest temperature possible in the region where your greenhouse is located.
Assuming you need a temperature of 70 °F& the lowest possible exterior temperature is 30 °F, you would get this…
Ideal greenhouse temperature: = 70°F
Coldest outside temperature: = (30°F)
Now, to get the BTUs, you’ll need to multiply your surface area by the temperature difference:
i.e.BTUs =Greenhouse Surface Area X Temperature differences
Using the figures in our example, you would get 600 x 40 = 24,000 BTU’s
Your heater will, therefore, require 24,000 BTU’s to adequately warm your greenhouse.
And so, 24,000 BTU’s would be my magic figure when shopping for a greenhouse heating system!
The following variables will affect your calculations:
Some glazing materials are better. For example, if your greenhouse is built with polycarbonate or double glazed glass, your heat requirement will be 30% less
This means it’s safe to take 30% of your BTU value as your heating requirement.
Walls made of brick or cement barely lose heat.
Thus, if that’s the walling in your greenhouse,you will need to go back to your surface area calculation stem and reduce it by ½..
Yeah. That’s right.
For step iii, take ½of your surface area value.
So, if my greenhouse is made of cement, my BTU value would be: (½ of 600)= 300 x 40 = 12,000 BTU’s !
Expert Greenhouse Heating Tips
This will help you avoid the losses that arise with insufficient warming, for example, lower yields and huge energy costs.
And as you have seen, the steps are so basic.
So, try it and let us know if it helps!