Can I use an Infrared Heater in my Greenhouse? 

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infrared heating in greenhouse

A greenhouse is an excellent gardening space for keeping your flowers, fruits, and plants safe from harm and extreme environments. Even better, it allows for year-round growth and nurturing, regardless of the weather condition outside the greenhouse. In addition, they prevent mold and fungi from developing on your plants. 

However, to produce abundant crops from your greenhouse during the cold winter season, it’s necessary to use specialized heaters to heat the space. More importantly, this will help you to maintain optimal temperature conditions in the greenhouse for good plant growth. Luckily, there are many heating devices for greenhouses out there, with many private gardeners and agrofarmers learning about infrared heaters. 

But is infrared heat safe for use in greenhouses? Can you use infrared heaters in your greenhouse? Read on to discover if infrared heating is an excellent option for heating your greenhouse! 

How do Infrared Greenhouse heaters work? 

Infrared heating devices work on the basis of natural solar heating, meaning that they emit rays that are absorbed by various objects. In turn, these rays provide the needed thermal energy. Most IR heaters have robust metal housing and sealed glass tubes that house the heating elements. These heating devices use a very simple principle of operation. Specifically, energy is transferred to a reflective surface, which then distributes heat evenly over the greenhouse. 

The emitted infrared radiation travels at the speed of light and follows a straight path. More notably, the heat is first transferred to objects like trays, plants, soil, benches, and the floor in the greenhouse. These objects distribute heat in all directions through other methods of heat transfer like conduction, convection, and radiation. This distribution of heat to various surfaces leads to an increase in the infrared temperatures of the whole indoor environment. In addition, the heated objects transfer heat to the air through convection, increasing the air temperatures. 

On the downside, infrared-heated greenhouses usually feel cold. This is because, unlike conventional systems, infrared heaters don’t heat the air. Other than that, infrared heating can be used in greenhouses, especially on uniformly low-growing crops like potted crops and bedding plants. 

Benefits of heating Greenhouses with Infrared Heaters 

Like another heating system, infrared heaters maintain a comfortable temperature in your greenhouse to ensure your plants are healthy during the cold weather. In addition, these systems offer many other infrared heating benefits, making them a better option than other types of greenhouse heaters. 

  • Energy efficient 

First, infrared heating is more economical than conventional heating systems. This is because the devices heat plants directly as opposed to convection heaters that must heat the air first. As a result, replacing your conventional heating system with infrared heaters in your greenhouse will reduce your heating costs by about 40 – 60%. Specifically, IR heaters eliminate the need for overhead air ducts and reduce the electricity cost for recirculating fans. Here’s how much electricity infrared heaters use! 

  • Maintain air temperature 

In addition, infrared heating ensures that the air temperature stays almost the same anywhere in the greenhouse starting from the floor to the peak. However, it leaves the soil and plant leaves heated. This allows the greenhouse to operate at a much lower temperature compared to conventional houses which cannot prevent the leaves and soil from freezing. Even better, these conditions will allow your greenhouses at lower humidity and heat levels, providing the added benefit of inhibiting bacterial growth. 

  • Uniform Heat Distribution 

Another benefit of infrared heating is that it ensures uniform and directional heating of a specific area of the greenhouses. Plus, it leads to small thermal losses and high efficiency. Better still, infrared heaters emit heat instantly, ensuring your greenhouse is heated immediately after turning on the device. These factors make the ideal for greenhouses with poor insulation or in colder regions. 

Infrared heaters can warm up the soil up to a depth of 5 – 7 cm. This creates the necessary soil conditions for successful plant growth and stimulates the plant’s root system. Specifically, infrared rays can warm the soil up to 28 degrees, which is the ideal temperature for plant growth, while maintaining the air temperature at 21 degrees. 

  • Infrared heating doesn’t dry the air

On the same note, infrared heating doesn’t dry the air, thus maintaining constant humidity in the greenhouse. More notably, this is a necessary requirement for promoting the good growth of all kinds of fruit crops and vegetables. At the same time, these devices provide reliable and uninterrupted operation throughout the day since they’re highly durable. Moreover, they rarely wear out or require repairs due to the lack of moving parts in their design. 

  • Compact design

Lastly, greenhouse infrared heaters have a compact design, making them easy to move around. Plus, they’re quite easy to install as they come with clear step-by-step instructions. Best of all, they’re suitable for creating optimum temperature conditions in various premises including greenhouses, warehouses, garages, etc. 

Different types of Infrared Heaters for Greenhouses 

Infrared heaters are usually classified according to the type of energy used to run them.

Gas-powered heaters usually have a greater heat output than their electrical variations. For that reason, they’re mostly used to heat the large-sized greenhouse with a ceiling height of over 10m. More importantly, they either run on coke oven gas or natural gas.

 Most gas infrared heating devices used in greenhouses are low-intensity IR heaters that mix air and gas and burn it in a heat exchanger tube. Low-intensity IR heaters are safer than high-intensity models for use in greenhouses. This is because they produce temperatures of up to 1100 deg F, while pipes of high-intensity IR hearers can get as hot as 1800 deg F. 

Despite the high heat output of gas heaters, electric infrared heaters are the most commonly used type of IR heaters for greenhouses. All thanks to their small and compact design, simplicity in operation, and high efficiency. Electric IR models can be further classified into; film, ceramic, and carbon infrared heaters. 

Each type of electric infrared heater has some unique features. For instance, film heaters are reliable and easy to install, while ceramic models are well-known for their strength. This helps ceramic heaters to heat up to a certain temperature quickly and cool down quickly. On the other hand, carbon IR heaters consume less energy than their ceramic counterparts but are more costly. 

Alternative greenhouse heaters to infrared heating 

There are various space heaters in the market that you can use to warm your greenhouse. Some of the best types of greenhouse heaters used by gardeners include; 

  • Electric heaters 

Electric heaters are safe to use in a greenhouse since they are a clean source of heat. Therefore, you can leave them turned on unattended by setting the desired temperature level. Moreover, they’re preferred by most gardeners since they heat the greenhouse fast and efficiently. However, since these units run on electricity, it’s recommended that you only use them in closed spaces to avoid the risk of a fire hazard. 

Another issue with electric heaters is that they’re ideal for small greenhouses. However, you’ll need to buy 3 or 4 units for a big greenhouse, which can lead to higher utility bills. 

That aside, there are 2 types of electric heaters you can use to warm your greenhouse; radiant and convective heaters. Convective heaters work to heat the air in the greenhouse when all doors and windows are closed. On the other hand, radiant heaters including infrared heaters direct heat the objects in the greenhouse instead of air. 

All in all, both types run on electricity and feature knobs that you can use to control the greenhouse temperature. 

  • Ceramic heaters 

Ceramic heaters use electricity to produce a lot of heat, despite being in a small box. On the same note, this compact design makes them highly portable, allowing you to take them anywhere heat is required. In addition, these units are affordable, pose minimal to no fire risk, and don’t get too hot to the touch. 

Unfortunately, you can use ceramic heaters to warm a bigger area, so they’re unsuitable for large greenhouses. However, they’re ideal for heating small greenhouses as they work well in small & enclosed spaces. 

  • Oil filled heaters 

Although oil-filled heaters look like regular radiators, they are only powered by oil and electricity. For that reason, they use less electricity compared to typical greenhouse heaters. In addition, they’re more cost-effective and come with wheels for optimal portability. 

  • Conventional fuel heaters 

As the name suggests, conventional fuel-based heaters use traditional energy sources like natural gas, wood, and kerosene. These units effectively heat both small and big greenhouses. However, they’re specifically intended for heating large areas and should not be used in enclosed or small spaces. This is because they produce toxic carbon emissions, which can be harmful to the plants and gardener’s health. For that, they should only be used outdoors and in well-ventilated greenhouses. 

  • Portable heaters 

Portable space heaters are lightweight and easy to carry around, making them the perfect option if you want a greenhouse heater you can move a lot. Most of these units are equipped with wheels, making them easy to move around your greenhouse. 

On the downside, they’re usually operated by electricity, which can lead to a high electricity bill. Moreover, they pose a fire risk, so you need to be very careful when using them around your greenhouse. 

Factors to consider when choosing the right heater for your greenhouse 

There are a few important aspects you should consider when looking for the best heating system for your greenhouse. Some of these factors include; 

  • Size of the greenhouse
  • Type of plants you want to grow 
  • The number of plants you intend to grow. 
  • The most affordable fuel source in your area
  • How cold your location gets 
  • The level of greenhouse insulation 

Various plants require different temperature conditions to survive. Some plants need cool weather, while others survive in warm weather. Therefore, the ideal heating system will be determined by how you intend to use the greenhouse. For instance, you have to consider whether you’ll be using a fraction of the growing space or whether the greenhouse will be filled with plants. 

In addition, you’ve to consider how you’ll be managing the greenhouse in winter. Otherwise, it will be difficult to choose the right heater for your greenhouse. As an example, if you’re using most of the green to only grow hardy plants, you can either use a small space heater or a DIY heating system. Similarly, if you’ve got a larger house that you don’t fully use during the cold season, you may need a heater to keep up with these severe conditions. 

The size of the greenhouse also plays a significant role in selecting the best type of heating device. Also, make sure that your greenhouse has the proper insulation to prevent the heat from escaping. Sometimes, you don’t necessarily need a greenhouse heater if it has top-notch insulation. Instead, you can use DIY heating ideas like installing heat-absorbing rocks under the frost line. 

What’s the best type of heater for your greenhouse? 

Gas- and electric heaters are the most commonly used types of greenhouse heating devices. Most gardeners prefer gas-powered models since they’re affordable in their local area. However, using gas heaters in confined spaces can be bad for your health and your plants’ health since they produce a considerable amount of fumes. So, if you’re planning to use gas heaters, make sure your greenhouse has adequate ventilation. 

Electric heaters, on the other hand, are quite popular due to their efficiency to maintain warmth at a consistent level. Even better, they don’t emit any toxic fumes, making them ideal for greenhouses with inadequate ventilation. For these reasons, electric heaters are the best and easiest way to heat a greenhouse. Moreover, there are many electric models out there, including the best-infrared heaters for greenhouses. 

Alternatively, you can invest in a large fan-based heater, but it’s a bit expensive. Other than that, these heaters allow you to precisely control the temperatures inside the greenhouse since they’re equipped with inbuilt thermostats. On top of that, fan-based electric heaters ensure that warm air is circulated around the entire greenhouse. 

How many British Thermal Units (BTUs) do you need to heat your greenhouse? 

BTUs show the amount of heat output produced by a heating device. In our case, the ideal greenhouse heater size will be influenced by various factors like greenhouse usage, insulation, and size. 

Generally speaking, 10,000 BTUs can cover an area of about 400 – 450 square feet, while 20,000 BTUs can cover up to 1,000 square feet if the greenhouse is well insulated. However, as you know, most greenhouses don’t have that much insulation. To determine how well insulated your greenhouse is, check its K- or R-Value. Also, consider the lower temperatures in your area during winter as well as the types of climate you intend to create in the greenhouse. 

When it comes to infrared heaters, it’s important to consider the area of the greenhouse as it will directly affect its performance. Interestingly, some IR models can emit enough heat to warm an area of about 5 – 100 sq m. Even better, most of these devices are highly portable, allowing you to move them from one place to another with ease.

In addition, electric IR heaters are ideal for greenhouse owners who are concerned with safety since they’ve various safety features and are much easier to install. You can either suspend them in a hinged greenhouse ceiling, mount them on the ceiling with anchor fasteners or mount them on the wall using tripods. On the other hand, mobile units are equipped with legs or wheels, making them easy to move around the greenhouse. The other benefit of electric IR heaters is that you don’t need to build additional air vents to get rid of combustion products. 

Conclusion: Can I use an Infrared heater in my greenhouse? 

Infrared heating is an economical solution for hard-to-heat spaces like greenhouses. This is because infrared heaters emit sin-like rays that are absorbed by surfaces and plants in your greenhouse. They promote uniform heat distribution inside the greenhouse, thus creating optimal conditions for plant growth. Moreover, they don’t create drafts, which are undesirable for many vegetables & herbs. Best of all, infrared heaters are highly efficient and allow you to grow plants all year round. So, if you live in an area that experiences winter, the answer is Yes, you can use an infrared heater to supply heat to your greenhouse! 

People Also Ask 

  • Do infrared heating devices harm plants? 

While infrared heaters are safe to use in a greenhouse, too much-infrared light, especially on the far red end of the electromagnetic spectrum can harm the plants. The heat may kill or discolor plants, especially if you have not recently watered them. For that reason, you should stick with low-intensity infrared heaters to warm your greenhouse. 

  • Why choose low-intensity infrared heaters for your greenhouse? 

Low-intensity IR heaters emit radiation with wavelengths of about 2,000 – 10,000nm. Plants respond to a light spectrum known as photosynthetic active radiation for photosynthesis. This spectrum (PAR) has a wavelength range of around 380 to 740nm which is shorter than the low-intensity infrared wavelength range. Moreover, choosing your greenhouse with low-intensity infrared heat will lead to healthier plants and lower heating costs. 

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