A decent greenhouse heater can make all the difference to your plants during midwinter to protect them from frost and ice. And the good news is is that you can pick up a decent heater for your greenhouse relatively cheaply.
Obviously, you need to assess your needs and relatively cheaply is dependent upon your greenhouse, it’s dimensions and what you’re growing. If you only have a smallish area to heat inside your greenhouse you can effortlessly pick up a greenhouse heater for the job for less than £30. If you have a larger greenhouse or need a bit more humph, then the price tag of a good greenhouse heater could run into the £100s. It’s significantly imperative, therefore, that you are sure of what you need for your greenhouse and your plants to ensure you get the right bit of kit.
The insulation on most plastic greenhouse have quite a low insulation value and so the purchase of the correct greenhouse heater is important to replace any lost heat. The use of either an electrical heating system, or paraffin heater, are in my view the best preference when looking to replace any heat loss. Furthermore, a thermostat is vital to make sure you can correctly control the temperature within your greenhouse and fortunately, most variants of heater come with one already installed.
If I stick my neck on the line, I’d advise against a propane gas heater – certainly if you’re just starting up – as you can spend quite an amount for a good model. Nevertheless, that’s just a subjective opinion on my part and I certainly won’t rule out a gas heater on the basis that it wasn’t up for the job (and gas heaters have potentially the lowest running costs). However, a decent paraffin heater doesn’t cost too much so they are worth looking at.
Talking of which, you do need to take into account the running cost of your greenhouse heating system. At the time of writing, the average electricity cost per unit is in the region of 15p (depending on your supplier and tariff) which means a 2000w heater will cost about 30p for every hour (60p for a 4000w etc). A paraffin greenhouse heater, however, could cost twice as much for the same length of time. That might have made your eyes swell – but the advantage of going with oil is that the heater will take time to cool and so you get “free” heat for a period of time after you’ve turned it off.
My own personal first choice is an electrical glasshouse heater as I like the “cheaper now” option as I don’t have avast budget and with the inbuilt thermostats on most products these days, I can keep the temperature within my own greenhouse just right, but don’t let that put you off a paraffin or gas heater if your need or budget stretches that far – each option does an excellent job of keeping the temperature of your glasshouse just right.