What is Greenhouse: Definition and 66 Discussions

A greenhouse (also called a glasshouse, or, if with sufficient heating, a hothouse) is a structure with walls and roof made chiefly of transparent material, such as glass, in which plants requiring regulated climatic conditions are grown. These structures range in size from small sheds to industrial-sized buildings. A miniature greenhouse is known as a cold frame. The interior of a greenhouse exposed to sunlight becomes significantly warmer than the external temperature, protecting its contents in cold weather.
Many commercial glass greenhouses or hothouses are high tech production facilities for vegetables, flowers or fruits. The glass greenhouses are filled with equipment including screening installations, heating, cooling, lighting, and may be controlled by a computer to optimize conditions for plant growth. Different techniques are then used to evaluate optimality degrees and comfort ratio of greenhouses, such as air temperature, relative humidity and vapour-pressure deficit, in order to reduce production risk prior to cultivation of a specific crop.

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  1. Nik_2213

    Writing: Input Wanted A 'failed' Runaway Moist Greenhouse: Need help to model...

    I'm trying to model an Earth-sized exo-planet, ~1.1g, with 'failed' Runaway Moist Greenhouse... Slightly smaller core than Earth's, with thicker mantle and crust. So, larger than Earth, but not by much. Sitting near inner-edge of 'Hab Zone' of Early-K-type star, orange-ish rather than Sol's...
  2. DaveC426913

    Can I save anything in my greenhouse from frost damage?

    We moved from a house with virtually no windows to a house with a 350 square foot sunroom. We went from 2 tiny plants to 27 medium and large plants. We have more money than sense. Plants were all doing great until the temp outside dropped to near 0C. (I did check that they were all hardy enough...
  3. hagopbul

    Climate Problems: Debating the Science Behind It

    Hello All : Reading about climate problems , and noticed that there is some deniers or people who do not convinced with the climate problem scientific ideas ( or theories ) may i ask what scientific claims they use to refute the current scientific explanation for the climate problems ? is...
  4. F

    A Average temperature in a greenhouse

    Hello everyone, since several weeks, no response from the other forums, I tried to compute a simple model for a greenhouse in a garden. First idea was to compute mass transfer, Navier-Stokes and heat equation all together but in my knowledge no analytical solution exists.I need to build a simple...
  5. J

    I Heating gasses in space -- How could we make a greenhouse in space?

    I was thinking the other day about green houses and how they would act in space or on another planet without an atmosphere. I know that green houses work on Earth by stopping convection but could they theoretically trap heat in a non atmospheric environment? I am imagining a material that allows...
  6. P

    Environmental Physics - Radiative forcing effect on greenhouse effect

    I think part (a) is simple enough. Here is what I have done. (a) ##G=\sigma T^{4}_{s} - OLR## $$ =\sigma (294)^{4} - 160 = 254 Wm^-{2} $$ Part (b) is where I am confused. I think I'm supposed to apply the second relevant equation, in order to get the change in average surface temperature due to...
  7. Graeme M

    Simple explanation of greenhouse effect - right or wrong?

    This is a very simple question. I've read a fair bit about the greenhouse effect and how GHGs affect the Earth's surface temperature and I know it can get very complex. But if I boil it down, it seems to be a very simple thing. Am I right to think of it this way? Radiation from the sun reaches...
  8. Leo Liu

    Research on greenhouse cultivation

    Hi all. I am doing a secondary research assignment about greenhouse. My research topic is to use greenhouses to alleviate the severity of food insecurity in disadvantaged regions. I did some research using google scholar and found nothing useful but the paper below...
  9. J

    Is the concentration of greenhouse gases proportional to the temperate

    I can't seem to find an answer to this: If the present level of greenhouse gas concentration were not to change, would the temperature of the planet continue to increase? Or would it level off? Or is a continually increasing concentration of greenhouse gases required to keep raising the planets...
  10. A

    Heating a small greenhouse - heat loss

    I have to build a small green house and to calculate if one heating wire is enough (or even too much...) Just for my curiosity I would like to understand the physics implied in this. The starting point is the desired dimensions: two modules of greenhouse with the following dimensions: 60 cm...
  11. E

    How would lower oxygen affect the greenhouse effect?

    If a terrestrial, earth-like planet had an atmosphere similar to Earth but with only around 15% oxygen concentration and 84% nitrogen, what impact would that have on the greenhouse effect of the planet's atmosphere? Are there other factors that would be relevant to calculating the greenhouse effect?
  12. M

    Do greenhouse gases need to be polar?

    Hi, I have been wondering if greenhouse gases always need to be polar molecules. Can a gas also absorb energy, and heat up, without being polar?
  13. W

    Perception of Intl Journal of Greenhouse Gas Control - Impact Factor 4

    The international Journal of Greenhouse Gas Control. It has an Impact Factor of around 4, but what's the perception? Is it respected? Is it considered a good journal? There isn't a qualitative judgment online. My boss seems to look down on it, but it has a good impact factor.
  14. A

    I Growing food in space - a 3rd concept

    To grow food in space, I have read about two designs of greenhouse. One is a pressurised greenhouse with wide expanses of thickened glass. The other is indoor stacks of shelves with LEDs driven from solar PVs outside. But would this third design work? Have a rotating mirror to focus light into...
  15. R

    Radiative forcing / Greenhouse effect

    How does radiative forcing relate to the greenhouse effect? Is radiative forcing part of the greenhouse effect? Or does radiative forcing cause it? I'm confused. Clear explanation needed. Thanks
  16. Jefffff

    Thermodynamics of an Arctic greenhouse?

    For a business project, I'm looking into the viability of a greenhouse situated in Canada's far northern town of Iqaluit. The problem is how to mathematically simulate the internal air temperature of the greenhouse. What I already have are detailed 3D renderings of the greenhouse as well as all...
  17. S

    Is greenhouse interior much cooler if reflective inside?

    Let's assume typical 10' X 20' greenhouse for growing veggies is empty and is all exposed concrete black floor with solid black (opaque) insulated knee high walls all around. The rest of it is glass sides and roof. Also, assume reflective radiant barrier was hung on those knee walls inside...
  18. haruspex

    Insights Frequently Made Errors in Climate Science - The Greenhouse Effect - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors in Climate Science - The Greenhouse Effect Continue reading the Original PF Insights Post.
  19. G

    NASA's greenhouse effect not correct?

    NASA says Earth's greenhouse effect makes Earth 33 C hotter than the Moon. All of that warming can be explained by Earth having 1 bar of pressure compared to the Moon having no pressure. Going from the Moon to Earth is like going from the top of the troposphere to sea level, roughly speaking...
  20. AotrsCommander

    Greenhouse effect on planetary equilibrium temperature help

    I am trying to back-calculate the greenhouse effect on planetary equilibrium temperature for Earth (in the hope I can then attempt applying it to other calculations.) I know that the actual equilibrium temperature of Earth is 287.89K, +33K above the calculated equilibrium temperature: Teq = (Q...
  21. RaulTheUCSCSlug

    Greenhouse effect affected by Earths Gravity?

    Hey, so I was thinking how the atmosphere is held close to Earth due to gravity and realized that if certain molecules have a certain amount of kinetic energy, they are bound to leave the atmosphere correct? I mean there is an escape velocity that these molecules must need and I'm sure molecules...
  22. Let'sthink

    Is Greenhouse Gas the Main Cause of Global Warming? Experiments and Evidence

    As I understand and I think correctly, that Green house effect is in essence conversion of lower wavelengths in the Sun's energy to higher wavelength near infrared regions which can heat up the medium more efficiently. So if we have a closed transparent box containing some amount of green house...
  23. avito009

    Quantum Physics behind the greenhouse effect.

    I read that when heat passes through the glass of a greenhouse it gets absorbed by the Earth inside the greenhouse. The Earth reflects this heat but these rays are of longer wavelength so it bounces off the glass and inturn heats the greenhouse more. Now the heat coming from the sun is...
  24. Graeme M

    Greenhouse effect and Earth's surface temperature

    I posed this question in the Earth section of the forums, but I think I wasn't clear enough in how I posed my question, plus I think the question is more physics than Earth science. I have decided to try posing my question as a series of questions building to the main point. This is because I...
  25. J

    AP Physics & Greenhouse: Electrical & Thermodynamics Solutions

    Hi there, I'm a high school physics teacher and my school has recently built a greenhouse! I am trying to find ways that I can have my AP level physics students participate in the greenhouse project, but I'm finding that anything I can think of seems to be well beyond the scope of the course...
  26. M

    Energy project for Universities implementation

    Hello all, this is my first time posting here so please excuse if this maybe isn't the appropriate thread to post this in but I figured it may be the most relevant. I am working on writing a proposal (small, just 450 words), that aims to address the energy efficiency of a university, ie...
  27. K

    Greenhouse Effect and Pets in Automobiles

    I have a question about the greenhouse effect that I hope you all can answer. My neighborhood went bonkers last night b/c an older woman left her dog in her car at 10:30 pm to do some grocery shopping. It was dark, but it was 84 degrees. I know this would be extremely dangerous if the...
  28. B

    I need your help for my solar power greenhouse fan project

    Hello everyone, Firstly thank you for taking the time to read this! I am a complete electrics beginner, so forgive anything stupid I say. I'm also typing this on a phone, so sorry for the odd nonsensical word! So here is what I am trying to do: I have a small greenhouse, the plastic kind...
  29. F

    Greenhouse Gases: Explaining the Impact of CO2 & CH4 on Global Temperature

    How would I answer the question: explain why even small amounts of CO2 and CH4 can have a large effect on global temperature?
  30. N

    Just wondering what has the greatest greenhouse effect

    Which of the following has the greatest greenhouse effect, on a per-pound basis? CFC-11 Carbon Dioxide HFC-23 Methane Nitrous Oxide
  31. D

    Using energy to scrub the atmosphere of greenhouse gases

    I was wondering if someone could help me with the current and foreseeable technology to use Earth's energy (nuclear, hydro, etc.) to actually scrub the atmosphere of CO2 and other gases. I'm curious if this is even possible and how it might be done. I've been trolling the internet for this...
  32. H

    Greenhouse Gases: Why Is CO2 More Concerning?

    why are scientists now more concerned about carbon dioxide as a greenhouse gas rather than methane for example? many thanks,
  33. W

    Heat (radiation) without direct air transfer - greenhouse effect?

    Hi everyone I realized that I had a mistaken belief about the meaning of the term greenhouse effect. I thought that it refers to the phenomenon whereby there is an exchange of heat due to light but without there being a direct air contact between the body being heated and the surrounding...
  34. M

    Using the greenhouse effect for energy?

    Ok I don’t really know any reasons why this doesn’t happen already so I’m hoping some people can help. Is it not possible to induce a Runaway greenhouse effect in a controlled environment and then use it for energy production? If it is possible why isn’t it being done (too inefficient...
  35. Z

    Comparing Greenhouse Gas Properties: N2O, CO2, and CH4

    I have been given a report and a part of it is on greenhouse gases. What do you think are some scientific factors/properties I should use in a comparison matrix of n2o,co2,ch4. I have read something about the shape of the molecule of an atom affecting the IR rays it can absorb. Also please...
  36. J

    1D Heat Equation / Greenhouse Simulation

    I am trying to model a thermal mass for a greenhouse design. A thermal mass is basically a box of mass with high Cp buried in the ground with the top exposed to the inside of the greenhouse and all the other sides insulated. My model is based on the fact that during the day, there is a net...
  37. C

    The physics of the greenhouse effect.

    I have to do some research on the greenhouse effect (the physics of it anyway) I am not to familiar with the topic and am on a tight schedule. If anyone has some interesting links, thoughts please share. I am interested in the role of clouds in GHG (greenhouse gases), how much do we know...
  38. P

    Greenhouse Gases and Resonance

    Hi, I am now learning about climate change and have come across resonance. When I previously studied SHM however, I learned about resonance, and I believe I have a good understand of what it means. If the frequency of a driving force matches the natural frequency of the system, this leads to...
  39. V

    Greenhouse Effect & Heat Radiation

    Homework Statement I learned that the solar radiation entering the atmosphere heats up the Earth's surface and the heat then radiates from the surface to the rest of the atmosphere. Is the greenhouse effect mostly dependent on the heat radiating from the surface, or do the greenhouse gases...
  40. S

    The Greenhouse Effect vs. Blackbodies vs. Global Warming?

    Can anyone explain what the right approach to this stuff is? It's an area I am largely ignorant about. According to the Stefan-Boltzmann Law, the Earth should be -18C. Obviously, this isn't true because the Earth isn't a blackbody. But my questions: 1. Why isn't the Earth technically a...
  41. G

    Percent water vapor - greenhouse gas

    I'm have armchair interest in greenhouse gases. One of the interesting points is the amount of greenhouse effect that CO2 has versus water vapor. I go to this page http://www.climate4you.com/GreenhouseGasses.htm and find that the relative percentage of atmospheric humidity is 45%. I...
  42. F

    How exactly does CO2 behave as a greenhouse gas?

    Hi everyone, This is my very first post here, so hi! I've got a few questions about CO2 that maybe a physics buff can help me out with. I understand the basics about CO2 warming the atmosphere via absorption and re-emission (radiatively or kinetically) of Outgoing Longwave Radiation...but...
  43. P

    Experiments on Greenhouse Gases

    Note: This isn't intended to be a Global Warming thread but rather a Greenhouse Gases thread (they're not the same thing), so please let's not talk about Global Warming because I don't want it closed. I'm very interested on any feedback or thoughts anyone may have for my experiments...
  44. I

    Greenhouse Gas Misunderstanding?

    Okay so I am a first time poster, hello to my fellow scientists. I need an expert opinion on a simple question I can't get around: I understand that Carbon Dioxide will absorb more energy from whatever radiation it comes into contact with than, say, Oxygen. That being said, I imagine the...
  45. K

    Greenhouse effect (reflection vs transmission)

    Hi, In the study of the greenhouse effect, I know for a fact that short wavelength radiation pass through a glass container and heat up its contents. When its contents get hot, they will re-emit longer wavelength (and hence lower energies) radiation, which will then be unable to pass through...
  46. J

    Exploring Water Vapor: The Most Lethal Greenhouse Gas

    How is water vapour a greenhouse gas? how is it the most imporant and lethal one?
  47. O

    3 Questions about Greenhouse Gasses

    I like to think that I'm pretty good at sorting out the BS from the actual facts, but with global warming, I'm having a hard time determining what is actual science, and what is politicized pseudo-science. Just for reference, I have generally accepted that human actions have been responsible...
  48. R

    Model CO2 as Greenhouse Gas: Tips & Results

    I recently came across several apparently reputable sources (e.g., NASA, PBS) that describe a simple, elegant experiment intended to demonstrate carbon dioxide's role as a greenhouse gas. Each of them involves two sealed containers with thermometers - one containing air, the other containing...
  49. Andre

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    G. Gerlich, R. D. Tscheuschner (2009) Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics. International Journal of Modern Physics B, Vol. 23, No. 3 (30 January 2009), 275-364 (World Scientific Publishing Co.) see...
  50. D

    Earthward Upper Stratospheric IR Radiation Cancels Most Greenhouse Gas Effect

    Atmospheric gases play a role in planetary temperature regulation Carbon dioxide levels have been rising rapidly in the Earth’s atmosphere and are linked by the IPCC to “global” warming. Recent failure of measured temperatures to advance with increasing carbon dioxide has called this assertion...