05 March 2012 By Billy Hawkins
It is the time of year when nature starts waking up and we all turn to our seed packets to find out what worked well last year and what we need to learn from.
Traditionally it is also the time when people who have spent winter poring over Greenhouse brochures decide to take the plunge and armed with ideas and hopes they come to Alitex to discuss how to realise their dreams.
Structural details help with optimising the growing environment for your plants, and obviously siting your structure thoughtfully ensures you utilise the sunshine. However, in order to run a greenhouse for twelve months of the year, you will need to think about heating and what your requirements might be. It is better to do the job once correctly than to revisit the subject later, when certain choices would be unavailable and impossible.
Heating, ventilation and humidity are all related; at Alitex we work on ventilation being equivalent to 17% of the floor area of your greenhouse. The humidity needs of your plant collection will depend on the temperature management and there are a number of options available to you, although essentially they run along the cold/frost-free/temperate (under which most plants flourish) or tropical categories. Obviously different zones work in larger greenhouses where temperatures can be carefully regulated with the introduction of internal walls and doors.
Aside from thinking about your plant needs and the size of your proposed greenhouse, you should look outside – what is the lowest temperature your local weather sinks to? Armed with all these factors we are then in a position to begin making appropriate recommendations.
Working in partnership with greenhouse heating experts Harrier Heating, we are well placed to share the benefits gained from years of experience of what will work for you. Generally speaking, for a greenhouse with an area of less than twenty metres squared, an adequate, cost effective and low maintenance option is the electric heating system, usually a fan heater. Fan heaters can however lead to dry heat and hot spots, but are great for frost prevention. You may prefer tubular heaters, which heat through convection, which does not dry out your plants and gives good temperature distribution. The downside to both tubular and fan heaters is that it does not modulate the heat, meaning that once the optimum temperature is reached the heating switches off and then does not switch on again until the temperature has dropped.
Tubular heating can be used for greenhouses up to forty square meters, anything larger than that you need to look at the premier system - the hot water heating option where water is pumped from a nearby boiler through pipes which run in channels underfoot. These channels are protected by stylish iron panels. The heat in this system is modulated and controlled by an outside head and provides the ideal growing temperature for your greenhouse. Thermostatic and environmental controls can be supplied from the very simplest to the most sophisticated. The added benefit with the premier system is continually circulating water in the pumps during the summer months which allow the greenhouse to cool evenly.
We have all the bases covered for artificially heating your greenhouse and we also have renewable options available. We can speak with authority and experience in our advice to you. Give us a call on 01730 826 900