Excessive Polytunnel Heat Prevention and Irrigation

19th Jul 2022

With temperatures hitting a record high, being able to control the heat of your polytunnel is the second-best decision you could make, the first being the purchase of your polytunnel.

Our polytunnels come with many ventilation options, all of which can be fit retrospectively, or if you haven't as yet bought your polytunnel, they can be easily added on to the order during the configuration of your tunnel.

Ventilation


Side Vents

Over a certain length, some tunnels struggle with stagnant air in the middle where open doors cannot circulate. The best recourse for this is to opt for some side ventilation. This allows air to flow directly into the hot pockets of your tunnel and can be closed during cooler months, allowing better control over the temperature of your tunnel.

Depending on the width and placement of the tunnel, you can install side vents on one side or both. A more exposed tunnel may only need side vents down one length, but a sheltered tunnel will not see the same results and may require both sides to be open to ventilation. Side vents work in conjunction with open doors, allowing full circulation through the tunnel.


Roof Vent

For people looking to release heat as opposed to promoting circulation, a roof vent may be the perfect solution. Cord operated with a spring closing mechanism; this is a great way to control the temperature in your tunnel. If you have concerns over adding side vents (maybe too exposed?) then opening doors can introduce fresh air, while the roof vent releases the heat and humidity.

Another key thing to remember with polytunnels is that height and length factor into how much ventilation you will need, as well as the placement of your polytunnel. Though longer tunnels are prone to hot spots of stagnant air, tunnels with more height will have better air circulation. As tempting as it is to buy a long low tunnel to optimise growing space, ensure it is ventilated properly. This will help you have the healthiest crops that are not plagued by disease or baked.


Doors

An obvious solution, however, it is common practice to see polytunnels with their doors propped open during the summer to promote ventilation and pollination. This does leave your tunnel vulnerable to pests looking to nibble on your flourishing crops, though this can easily be resolved with some strong netting.

Depending on the length of your tunnel, your door may be enough to maintain the temperature, however, for many tunnels, it is not enough through the height of summer. Our doors are available with PVC ventilation panels, allowing the perfect level of air when you are looking to maintain circulation without keeping the door open.


Irrigation


Overhead Irrigation Kit

Available in three lengths, 25ft, 50ft & 75ft, the overhead irrigation kit simply fastens to the central ridge of your polytunnel with individual sprinklers suspended on 30cm drop tubes.

The sprinklers (once connected to a water source) imitate rainfall gently watering the whole area inside your polytunnel tunnel.

The kit is supplied with commercial sprinklers, all the necessary fittings and a hose connector.

This central, single sprayline is suitable for polytunnels up to 16ft wide and can be operated with a water timer should you need to.

Drip Line Irrigation Kit

An ideal low-level watering system which places the water where it is required without wetting foliage/flowers or soaking the pathway. Supplied with all the necessary fittings, drippers and a hose connector. The drip line irrigation kits are supplied with enough pipe and fittings for both sides of the polytunnel and are available in 3 lengths, 25ft, 50ft or 75ft.

The Drip Line Irrigation Kit is ideal for polytunnels and raised beds, simply connect to your water source and feed down the length of your bed. The drip-line has pressure compensating emitters positioned every 30cm (12”) along the pipe to ensure even irrigation along the lines (there are three lines per kit per length)

Self Adhesive Guttering


A perfect addition to your polytunnel, our Self Adhesive Guttering simply sticks to the outside of your polytunnel and catches the rain water allowing it to run off in to a water butt or three. 

All of these products can be purchased directly from our website www.northernpolytunnels.co.uk or simply give us a ring on 01282 873120.