What is Radiator: Definition and 69 Discussions

Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics.A radiator is always a source of heat to its environment, although this may be for either the purpose of heating this environment, or for cooling the fluid or coolant supplied to it, as for automotive engine cooling and HVAC dry cooling towers. Despite the name, most radiators transfer the bulk of their heat via convection instead of thermal radiation.

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  1. pozsar

    Water cooler radiator with unusual air flow direction

    Hi everyone! I'm doing a DIY project in which I have to use air cooling to regulate water temperatures of max 90°C. I want to use some cheap (possibly even used) pre-manufactured radiator to do the job for me (since I'm unable to make finned pipes with tight enough fittings to provide...
  2. camerart

    Photovoltaic vs. thermal radiator Solar Panel comparison (using a lens)

    Hi, Has anyone experience with photovoltaic solar panels and thermal radiator type solar panels? 1/ How do they compare when both have the same collection area? If the thermal radiator was much smaller than the collection area, and a lens the size of the collection area was used, focused on...
  3. organiclatte

    Air-to-Water Heat Exchanger - Car radiator

    I'm looking for a way to keep a liquid under 50°C. This liquid has a thermal conductivity of .1396 and a specific heat of 2.054 both at 40°C. and a constant energy source submerged in it ranging from 16KW to 17.5KW. I'm barely starting to read about this topic, according some forums, a car...
  4. S

    HVAC Attic to Pool Heat Exchange, will car radiator collect heat?

    My attic gets very hot even with the exhaust fan I installed. I would like to move than heat to my swimming pool. I currently have a FAFCO solar pool heater where the pool pump pumps water up onto my roof and thru the 12' long solar panel and down back into the pool. I would like to free up roof...
  5. T

    How will a ceiling extract valve affect a radiator?

    An apartment has a radiator, about 1000 W. Nearly right above it is an extract valve for the ventilation system which extracts 35 m3/h. The vertical distance between the two is around two meters. Is there a risk that this will prevent the radiator from functioning properly as the hot air will...
  6. G

    Car Radiator as Air-to-Water Heat Exchanger

    I am looking for a passive way to convert a supply of hot air into warm pool water. My pool can be in the low 70s without heat. Looking to get a 10 degree lift in pool temp. Pool is in-ground and relatively small at 8,500 gal. Water flow rate through the radiators can be regulated by valves...
  7. B

    Working out the rate of heat loss from a radiator

    Here is the Q below This is what I have tried so far. I ended up getting a value of 1772.4 watts Is this the correct way of doing this problem?
  8. S

    Can Using a Mass Heater Improve the Efficiency of a Radiator?

    Hello all, I suffer from having a very cold house - as it is rented, we cannot put insulation in or change the windows (single glazed!), so I am looking for non-permanent options to maximise the warmth we can get from it. We have a log burner, and I have found that it is still kicking heat out...
  9. Joe591

    Possible Causes for Hole in Radiator Tank

    What would cause a hole to form in the top aluminium tank of a radiator of an earthmoving machine. The tank material is 6mm thick and is made from 1050 aluminium plate. The material around the hole has bubbles almost like pitting corrosion or like somebody went and took a flame to it. The rest...
  10. Shivam2112

    Can I use a bigger radiator in place of a smaller radiator?

    I want to upgrade my radiator to a bigger one in my project formula car,with the same engine and pump, what are the cons of it. Probably going to upgrade from a bike radiator to a car radiator. Also please help with calculations and reports.
  11. C

    I What is the most efficient radiator shape?

    What is the highest efficiency (electromagnetic) radiator shape? Meaning, a shape with the highest radiated power/volume (radiated power is in this case dependent only on surface area and how much of the radiation is reabsorbed by the radiatior)
  12. kal

    I Trouble understanding the idea of a cavity radiator being a Black Body

    I have been trying to understand the role of a cavity as a black body radiator in the derivation of planks black body radiation law but it has left me with 5 main questions: 1. If an object is a perfect absorber it must also be a perfect emitter, meaning that (allowing for a cavity not being a...
  13. Arup Biswas

    Blue Light from a Blackbody Radiator

    From Wien's law it is seen that approx 6500K(Greater than sun's temp) needed to heat a body to blue! But we see so much blue light(uv ray)! Are they formed from any different mechanism rather than heating?
  14. T

    How does the size of a radiator impact its heat output?

    I'm involved in a project with central heating. Due to a miscalculation the apartment radiators are about 50% too large. The current system water flow is based on the assumption that the radiators are the correct size (i.e. smaller), even though they are not. Due to this the water takes longer...
  15. Greg Bernhardt

    Plumbing Insulating radiator pipes in basement

    Common advice is to insulate hot water radiator pipes in the basement so you're not wasting money heating the basement. However, I wonder if it's really cost effective. I have a ton of pipes zigzagging in the basement. Cheap pipe insulation only seems to come in sizes 1/2 3/4 and 1in. However...
  16. C

    How exactly does Hawking radiation work?

    Homework Statement For school I'm doing a project on hawking radiaton but I have very big difficulties trying to understand it. I'm trying to understand the matter about: Unruh effect, particle pair (antimatter - matter) and the theory of relativity regarding vaccuum. Homework Equations none...
  17. J

    Solving a Problem with LPHW Radiator

    I am trying to solve a problem regarding an LPHW radiator, of which the heat output is controlled by adjusting the LPHW flow rate. The relationship between the flow rate and the radiator output can be approximated by a first order transfer function with a time constant of 1 minute. The heat...
  18. Greg Bernhardt

    Troubleshooting Cold Radiator - Boiler Fall Start Up

    Turned the boiler for the first time this fall and an upstairs bathroom rad is stone cold. All other rads heat up. I fiddled with the valve, which is new, with no luck. What is strange is that even the pipe from the floor leading to the valve is cold. This is a water system. It must cycle. How...
  19. P

    I Force on a Spherically-Uniform Radiator Moving Through Space

    Let's say I have a spherically-uniform black-body radiator. It is losing energy, and therefore some of its mass, at a particular rate. From the frame of reference of the radiator, it has no momentum, but it has a changing amount of energy. From its frame of reference, the pressure on the...
  20. S

    Problem with refrigerator and radiator

    Homework Statement The following data refer to an electrically operated refrigerator: - Efficiency : ## \xi = 2.4## - Temperature inside: ##T_i = -9 ° C ## - Temperature of the radiator ## T_r = 40 °C ## - Room temperature: ## T_s = 35 °C## - Total surface of walls: ## A = 3.2 m ^ 2 ## -...
  21. Daringpear

    Formula for determining the heat dissipation of a radiator

    Are there any equations out there which can calculate the heat dissipation of a water-cooled radiator with a fan on it? I would assume some of the variables would include: -Volume of the radiator (240 x 199 x 45mm)=2149200mm^3 -Specific heat of water (4.187 kJ/kgK) -Specific heat of the copper...
  22. Messy Jesse

    Automotive Radiator Sample Calculations Help

    Hi all, As part of a school project, I'm attempting to demonstrate some sample calculations of a car radiator and I'm a little lost. I'd like to demonstrate some cooling requirements for the peak power output of my car engine: 325 horsepower at 4400 RPM. Can anyone offer any guidance as to...
  23. R

    Automotive Air speed in car radiator -- Heat Exchange calculations

    Hello, this is my first post. This question is related to my final thesis. I'm calculating the heat exchange area of a radiator through heat exchange equations: Q = U*A*LMTD I have as data Q, and LMTD (this one through trivial calculations) In order to calculate U, I need the coefficients...
  24. T

    Thermal Management Question in Spacecraft

    Hello guys, Below I am presenting a question related to thermal management in spacecraft . Perhaps many of you might find it interesting! And this could be a real-life problem for thermal engineering in a spacecraft . So, the question is following: An instrument dissipates 10W and, in order...
  25. J

    Black/white radiator vs white/black wall: radiation

    Hi, Situation A: Black radiator in a room with white walls. Situation B: White radiator in a room with black walls. Which one is the most efficient situation? I know that convection is dominant if you look at a radiator, but i would like to know the answer in terms of radiation. Thank you :)...
  26. A

    Overall Heat transfer coefficient for a radiator

    Hello all. I need to design a radiator for 43kw heat dissipation. I have used the LMTD method for finding out the contact surface area of the radiator. But I have a small problem. I cannot find the area unless i know the overall heat transfer coefficient. Can somebody please give an estimate of...
  27. S

    How to design a radiator to dissipate heat generated by a 39 KW rotary engine?

    No separate coolant is used, instead lubricating oil to be used for both lubrication and cooling of engine. How to calculate radiator size, coolant flow rate?
  28. G

    Calculating the effectiveness of a Radiator and Fan Combination

    Hello, I am trying to compare different combinations of Radiators and fans on their ability to cool water(or any liquid for that matter) Now I've been showen some Bernoulli's equation things and been pointed at Reynolds number but To be honest I haven't looked at any physics outside rigid...
  29. M

    How can I design a radiator for 100 kW of heat rejection?

    hi, all. I have to design a radiator rejecting 100 kw of heat.how can I find example projects.
  30. M

    A radiator in a domestic heating system operates at a surface temperat

    A radiator in a domestic heating system operates at a surface temperature of 55 C. Determine the rate at which it emits radiant heat per unit area if it behaves as a black body ? why we did not square the temperature I mean ( 273 + 55)^4 please I need your help
  31. T

    Adding Water to Car Radiator: 40% or 10% Antifreeze?

    The radiator of a car can contain 10 gal of liquid. If it is half full with a mixture having 60% antifreeze and 40% water, how much more water must be added so that the resulting mixture has only a) 40% antifreeze? b) 10% antifreeze? Will it fit in the radiator?
  32. Overflowing

    Black Body Radiator vs painted surface

    Recently on an aquarium related forum, I called out someone for making what I considered to be an outlandish claim and I was supported by several others. However I wish to get the opinion and/or facts explained by someone from a purely scientific standpoint. This has to do with the heat...
  33. I

    Transformer Radiator Design and Calculations

    Hey guys I'm BRAND SPANKING new to posting anything an any forum ever...this is a last resort at the end of much research, brainstorming and desperate googling... My problem: We've built a transformer tank to house the core and this will be filled with oil, a radiator was built as well...
  34. S

    Heat transfer through radiator reflector foils with data

    Hi all, We got these rad reflector foils to improve your heating bills in our shop today. Trying to figure out if there any good. As a really quick test to see if they do anything, i stuck one to the kettle and measured the temp difference with a thermal imaging camera. (pics attached)...
  35. M

    Help Underfloor v radiator case study

    Homework Statement 4. ANALYSIS The Excel Data File will allow the following analysis to be conducted for both emitter types: a) Calculate the variation in both the temperature drop across the emitter ( T) and total heat emitted (Q) over the entire test period for each of the 3...
  36. 5

    Automotive Where Can I Find DIY Car Radiator Kits and Cores for Aluminum Radiator Design?

    Hello I am new here, Can anyone share with me on how to design car radiator.:confused:
  37. G

    Radiator radiation. Which way to place clothes horse for the fastest drying?

    This is not so muc a homework question as settling an argument: I have a clothes horse on which clothes can be hung parallel to each other roughly 50 cm apart. I place the clothes horse perpendicular to the radiator so the heat from the radiates along the length of the wet clothes. However my...
  38. P

    I want to heat up my room, would a fan towards the radiator work?

    Hi, Might sound like a homework problem but since it isn't I posted it here. I currently live in a small 22m^2 student apartment. Heating is included in the rent, in the shape of a basic water radiator located below the window towards the wall (dont worry, there is nothing standing towards...
  39. J

    Solving Radiator Problem - Help Needed | Jefferson123

    Hi guys can anyone help I have a problem trying to find an equation to work out the heat rejection for a car radiator I have Heat exchange = u x a x deltaT But I cannot find u ? The radiators have flat profile tubes and wave fin they are made from aluminium, the formulae would...
  40. C

    ICE radiator waste heat recovery system?

    Hello all... I am new to posting, but have followed posts on here for a while and finally got myself stumped, so I'm looking for advice and thoughts before I go over my project budget only to find I over/under estimated something. I am currently building a biomass fueled electrical...
  41. Y

    Radiator plenum, and venting for proper airflow

    Hello all, I am working on a kit car project that is coming together in a way I had never expected. That preliminary stats are way above what I had expected. So I am getting very excited about completing this project. However now I'm into engineering the radiator its plenum and its...
  42. T

    Help with a Fractal based Computer radiator

    Now pardon me but my math isn't quite as good as it should be, But I've read a fair amount of mandelbrots material and the premise behind his theories as best as i can. The other week while looking at a liquid cooling radiator for my computer, i had the odd idea of instead of a single tube...
  43. sankalpmittal

    Why is black colour good absorber and radiator of heat ?

    I have read in my class 10th book and other books that black(usually dark) colour is avoided in summers and this is the reason why impure ice melts quickly . I am wondering why ?
  44. russ_watters

    Mini-Blinds on Your Car Radiator

    When I wrote this with regard to wind turbines on cars: ...I had no idea manufacturers actually did such things: http://www.usatoday.com/money/autos/2011-04-06-shutters-for-cars.htm Interesting stuff.
  45. C

    Electric Radiator: P=750W, V=230V, R=70.54 Ohms

    Homework Statement An electric radiator which is an ordinary constant resistor emits a heating power of 750 W at a mains supply voltage of 230 V. Homework Equations What is the total heating power in each respective instance when two such radiators are connected a) in parallel, and b) in...
  46. B

    Car Radiator Design: Tips, Challenges & Solutions

    Dear All, I am facing a problem in radiator design as I was unable to get a full fledge design procedure about the topic. Do I need to consider it as a crossflow heat exchanger or there is a specialized methodology? I performed some calculations by considering the flow of hot fluid as...
  47. D

    Fin & Tube Radiator: Complete Theory Explained

    i need complete theory of tht pleasez help me
  48. M

    Can the Sun be treated as a black body radiator?

    Hello, I am trying to revise for my Solar System exam and going through a past paper i have a question relating to something that we don't seem to have covered: "By estimating the energy output of the Sun's corona (in watts), comment on whether can be treated as a blackbody radiator...
  49. H

    Calculating Required Area for Radiator: Clarifying Confusion

    When calculating the required area for a radiator using the equation Mass flow rate of air = Required Area x density of air x velocity of air Does the Required Area mean the Surface area on both sides of the radiator OR does it mean the total surface area of the cooling fins and...
  50. Q

    Why is a rough surface a good absorber and radiator of infrared?

    Why is a rough surface a good absorber and radiator of infrared?