Choosing a greenhouse heater - which one is right for you
Winter is coming, which means its time to start moving your tender plants into the greenhouse to protect them from the elements. Youll also want to invest in a greenhouse heater, so you can keep growing and make sure that your plants survive during the cold nights ahead.
In this post, we look at the different kind of heaters available and their benefits, before examining a small selection of some of the best greenhouse heaters on the market.
Before you invest
Before you invest in a greenhouse heater, its important that you take steps to ensure that your greenhouse is properly insulated and free from draughts “ otherwise, youll lose most of the benefit of heating your greenhouse, and it will end up costing you a lot more!
Seal up any cracks using a flexible sealant, and make sure that all the seals on your doors are fit for purpose. Replace any broken panes of glass, and make sure your vents and doors fit snugly and close properly.
The right output
Its also important to consider what your goals are “ and asking yourself whether you are trying to provide your plants with frost protection, or want to heat your greenhouse will help you to purchase a model with the correct output.
Measure your greenhouse, then use this rough guide to help you choose the greenhouse heater thats right for your space:
1Kw - Heat 4.5m2 - Frost Protection 7.5m2
2Kw - Heat 5.6m2 - Frost Protection 11.25m2
3Kw - Heat 11.25m2 - Frost Protection 24m2
4Kw - Heat 14m2 - Frost Protection 32.5m2
6Kw - Heat 18.5m2- Frost Protection 46.5m2
The different kinds of heater
There are three main kinds of greenhouse heater: electric, paraffin, and gas, and choosing the right kind for your needs will pay dividends over the long term. Whilst some if it comes down to personal preference, they all deliver different benefits.
Electric greenhouse heaters are cost-effective to run, and there is no need to provide ventilation, so none of the warmth you produce will escape. Often, electric models are fan assisted and have a thermostat, which helps to provide an even distribution of heat, and minimises running costs. Many electric heaters have a fan setting, which can also be used to help circulate air during the summer months.
The downsides are that theyre only suitable if you have access to mains power in your greenhouse, and they are also more expensive to buy than gas or paraffin heaters.
Gas heaters are typically cheaper to buy than electric heaters and more flexible, as they dont require mains power. Unfortunately, they produce fumes, which need to be vented, which raises running costs and has an environmental impact.
Paraffin heaters are cheap and reliable, but theyre only really suitable for small greenhouses, cold frames and frost protection or as a back up heater for if your main heater fails. They will need topping up with fuel regularly, and the wick will need maintenance from time to time. Typically, they dont offer the same level of heat control that you get with a gas or electric heater.
Our pick of the best heaters
For the serious grower
Electric
Flexible, powerful and reliable, the electric Bio Green Phoenix is one of our favourite greenhouse heaters. Featuring a built in thermostat and fan, it will deliver easily controllable, consistent heating and great air circulation to prevent mould.
The Bio Green Phoenixs 2.8Kw output means that its big enough for the vast majority of growers - it can provide effective heating in spaces up to 100sq ft, and frost protection up to 180 sq ft. For added adaptability, the unit comes with suspension chains, so it can be hung from the ceiling, and sturdy feet for floor standing use.
Gas
Attractive, efficient, and with great output, the Bio Green Black Forest is a great alternative to the Phoenix if you dont have access to mains electricity.
Designed to be hyper efficient, it features thermostatic control and a catalytic burner that delivers a thermal efficiency of over 99%! The catalytic converter also keeps carbon monoxide production, reducing the need for ventilation.
The 3.5Kw output is suitable for the heating of spaces up to 100sq ft, with frost protection up to 180 sq ft.
For the Everyday Grower
Electric
The ideal heater for small/medium sized greenhouses and conservatories, the Bio Green Tropic features a fan and thermostat for control and air circulation, as well as a handy ˜frost-watch setting for added protection. Rated for use in spaces up to 60 sq ft (heating) and 140 sq ft (frost protection), the Bio Green Tropic also comes supplied with a full two-year guarantee for extra peace of mind.
Gas
Reliable, dependable and built to the highest standards, the Lifestyle Eden 2Kw is designed to deliver maximum performance, and provides effective heating in spaces up to 60 sq ft (frost protection to 140sq ft). With easy ignition and thermostatic control, its a great alternative for those without access to mains electricity.