What is the difference between Q-Heat and D-Gree?
In order to remain a strong and stable growth and prevent the crop from burning, shading agents are used on the roof of greenhouses. Shading agents are both chalk shading agents and diffuse coatings. Crops that are in need of a lot of sun, can be protected with a diffuse coating that spreads the light, rather than a light blocking layer of chalk. For sun-loving crops, chalk takes away too much sunlight. On the contrary, a diffuse coating’s main function is to spread the incoming light.
In this article, an explanation on the two different, yet similar shading agents is given. Q-Heat and D-Gree, what is the difference?
Shading of PAR and NIR light
Since every crop, every greenhouse and every climate asks for a different solution, four different diffuse coatings were developed:
- A diffuse coating which provides as much light as possible to the crops (D-Fuse) that make use of all sunlight they get, but do profit from the diffusion of this light.
- A diffuse coating which offers some extra protection (D-Fuse Extra) for crops that need to be protected against too much light and warmth.
- A diffuse coating (D-Gree) and chalk/ diffuse hybrid (Q-Heat) which has additional characteristics in terms of warmth resistance, can be used for crops that make use of a lot of sunlight, but are sensitive to too much light at the same time.
The resemblance in these Q-Heat and D-Gree is that both of the products spread the incoming light and make it diffuse up to 95%. The products’ differences concern the other specifications, such as the difference between shading of PAR light and NIR light.
PAR light
PAR light (abbreviation for ‘Photosynthetically Active Radiation’) forms a part of the sunlight spectrum, which is used by plants for photosynthesis and growth. This light is found in a band in the vicinity of 400-700nm, also called ‘grow light’. Even though a crop needs this light for its growth and other processes, it can also have enough of the light within this particular part of the spectrum.
NIR light
NIR light (abbreviation for ‘Near-infrared spectroscopy’) has a longer frequency than the PAR light and can be found between 700-3000nm. This radiation is not used for photosynthesis and growth, but is mainly transferred to warmth. A crop can profit from warmth to a certain extent, but in greenhouses this radiation of light often leads to an excessive and harmful temperature.
The perfect fit for my cultivation; Q-Heat or D-Gree?
Both PAR and NIR light are desired to a certain extent to ensure healthy growth of the crops. The differences in the two products (D-Gree and Q-Heat) can be found in the level of shading of PAR and NIR light. Both coatings contain special pigments which can distinguish PAR and NIR light, with a result of relatively more shading in the NIR-spectrum.
D-Gree can only be dosed in one standard way, namely 13 buckets per hectare. The coating shades 15-20% of PAR and 46% of NIR light. For some crops, greenhouses or climates, this level of shading is insufficient, meaning more shading of e.g. PAR and NIR light is needed. In such cases, Q-Heat can be used. This product has several options for dosage, varying from 17 to 44 buckets per hectare. In its highest dosage, 40% of PAR light can be shaded and approximately 70% NIR light.
In other words: the difference between Q-Heat and D-Gree is that in the end Q-Heat has a higher level of shading than the D-Gree.
Dosage D-Gree
| Buckets per hectare |
Shading in PAR +/- |
Shading in NIR +/- |
% HAZE (diffusivity) +/- |
Life span (weeks) +/- |
Rain resistance |
| 13 |
15 - 20% |
46% |
93% |
16 - 20 |
Maximum |
Dosage Q-Heat
| Buckets per hectare |
Shading in PAR +/- |
Shading in NIR +/- |
% Haze (diffusivity) +/- |
Life span(weeks) +/- |
Rain resistance |
| 44 |
40% |
70% |
90% |
21 - 24 |
Maximum |
| 33 |
30% |
65% |
94% |
18 - 20 |
Maximum |
| 27 |
25% |
60% |
95% |
15 - 17 |
Maximum |
| 22 |
20% |
50% |
93% |
12 - 14 |
Medium |
| 17 |
15% |
40% |
91% |
10 - 11 |
Medium |
Unable to maintain healthy growth of the crop with 15 to 20% shading of PAR light? Are you still experiencing heat damage with 46% shading of NIR light? Make use of a higher dosage of Q-Heat to be able to shade enough PAR and NIR light. Q-Heat gives more, where D-Gree stops.
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