What is Heater: Definition and 202 Discussions

Heating, ventilation, and air conditioning (HVAC) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation, as HVAC&R or HVACR or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers).
HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels and senior living facilities, medium to large industrial and office buildings such as skyscrapers and hospitals, vehicles such as cars, trains, airplanes, ships and submarines, and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.
Ventilating or ventilation (the "V" in HVAC) is the process of exchanging or replacing air in any space to provide high indoor air quality which involves temperature control, oxygen replenishment, and removal of moisture, odors, smoke, heat, dust, airborne bacteria, carbon dioxide, and other gases. Ventilation removes unpleasant smells and excessive moisture, introduces outside air, keeps interior building air circulating, and prevents stagnation of the interior air.
Ventilation often refers to the intentional delivery of the outside air to the building indoor environment. It is one of the most important factors for maintaining acceptable indoor air quality in buildings. Methods for ventilating a building are divided into mechanical/forced and natural types.

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  1. K

    Pressure losses in electric air heater

    I have an electric air heater with a pressure loss of 3kPa (according to manufacturer at the flow rate and temperature I will be using). Air is supplied to the heater using a centrifugal fan with a static pressure of 8.7kPa (gauge) and a flow rate of 88m3/hr, giving a dynamic pressure of around...
  2. E

    Using concentric pipes as an inductive heater

    Hi Everyone, I am a mechanical Engineer, playing in the electrical word :) I was thinking about creating an inductive heater, that was based on 2 concentric pipes, with a current flow path that is from the inside pipe, through to the outside pipe, and utilizing an induction power supply to...
  3. T

    Need Help in assembling an electrical resistance heater

    Hello Im looking to build a very small electrical resistance heater. It should produce no more than 1 to 3 degrees of heat. This is for a personal project of mine. I need to know what types of materials I need to use. Id like the device to be both battery powered and plug in. Can anyone...
  4. alexandria

    Solving Physics Homework: Power Output of Heater

    Homework Statement Homework Equations relevant equations listed with each question The Attempt at a Solution a) to solve for the power output of the heater, i used the following equation: Power = Energy/time i already know that Energy = Quantity so based on this, i can solve for Q = mass(ice)...
  5. J

    Adding extra socket share with water heater power supply

    It is safe to add on extra socket by this way? Original connection: postimg.org/image/v6nshoygh/ Add-on connection: postimg.org/image/vkoccsyu5/ The extra socket is for light usage only. Water heater is instant water heater without tank. The switch is double pole single switch.
  6. lasisdabomb

    Cotton Insulation vs Glad Wrap Bag for solar water heater?

    Hello Physics Forum. I have to complete a solar water heater project for school and choosing between what would be better for the insulation of a tin reservoir. I'm leaning towards the glad wrap bag because it will let more light hit our reservoir. However it will be a quite windy day and cotton...
  7. R

    Electric immersion water heater time

    Homework Statement The mechanical equivalent of heat is 1cal=4.18J. The specific heat of water is 1cal/g*K and its mass is 1g/cm^3. an electric immersion water heater rated at 400 W should heat a liter of water from 10C to 30C in about how much time Homework Equations R=v/i power=v*i The...
  8. R

    Max Heat Output of a Frenette Heater

    I Was wondering how a frenette heater works? By frenette I mean the one that works thanks to friction. What would be the maximum heat produced assuming that we take The most ideal situation. Thanks a lot.
  9. S

    Nichrome wire overheating failure in standard air heater

    Am experimenting with an Omega Engineering AHP 7561 standard air heater rated for up to 240v. Specs include ability to keep a 20 cfm flow exiting @1000F while pulling about 10A @220v. Nichrome melts around 2400F. I'd like to produce small bursts (lasting a few seconds) of very hot air, like...
  10. G

    What sort of EM field is produced in an induction heater?

    What sort of EM field is produced in an induction heater? And how to measure it? That's it, basically. Assuming an induction heater is running on 200khz, and consuming about 3000 watts, how would I go about measuring the magnetic field produced in its coil? Now, I'm rather confused about all...
  11. Pouyan

    Using heat pump to make a house heater

    A heat pump in winter heat energy from the bottom of a lake, where temperature is 4 ° C and delivers thermal energy in a home where the temperature is 22 C. What is the theoretical minimum power the heat pump must be supplied to you at home must be able to take out 4000 watts heating power ...
  12. ChipY

    AM Radio signal IS sounding from my wall heater

    I am a video and sound engineer. There is clearly AM radio coming from my wall heater. An earlier thread on this topic discussed the possibilities but ultimately left the subject with an assumed crazy old lady's false perception. I assure you this is happening. There is a 50,000W AM station...
  13. A

    Inductive Heater Homework: Find Current & Rate of Energy

    Homework Statement A 34.6 -cm-diameter coil consists of 25 turns of circular copper wire 2.25 mm in diameter. A uniform magnetic field, perpendicular to the plane of the coil, changes at a rate of 3.55 × 10-3T/s. Determine a. the current I in the loop, b. and the rate dU/dt at which thermal...
  14. E

    Transfer function - zero in a thermal heater

    Hi I am trying to characterize a microscale resistive heater. In my Bode plot there is decay that is less than -20dB/decade indicating that there is a zero in the system. Anyone having an idea of what physical meaning a zero in a resistive heater has? Thanks.
  15. L

    Gas fired water heater - sizing

    Hi Guys, I am aware how to calculate flow rate Q (c x dt), but when sizing a direct gas fired water heater there is no dt but of course need allow for temp rise, but what parts of information can be known and unknown and how would i even start to put a formula together? Ultimately i would like...
  16. DaveC426913

    Redirecting lost heat from propane heater

    I've got a propane heater out of my deck that I use on cold days to enjoy a fine stogie and a port. It loses a lot of heat straight up. I'd like to redirect that heat back to me. (But safety first, I know.) I've been thinking of a simple curved sheet of aluminum suspended above it, but I'm...
  17. K

    The voltage and an electric heater

    Homework Statement A 660[W] heater can work on 120[V]. if the voltage decreases to 110[V] what is the power that it consumes? Homework Equations $$V=iR$$ $$P=iV$$ For pure resistance: ##P=i^2R## The Attempt at a Solution The current at 660[W]: ##P=i\cdot 120\rightarrow i=5.5[A]## The...
  18. N

    Low voltage Low heat, battery powered heater

    Hey guys! I have been following the forum for quite some time now. With all of you smart people out there, I am hoping you can help me design a heater, or at least lead me in the right direction. What I am attempting to create is a battery powered heater, to maintain a temperature of...
  19. B

    Two 700 watt blow heaters vs one 1500 watt heater?

    I bought a small 1500 Watt portable blow heater for my room because it getting really cold, but whenever its turned on, it trips the circuit breaker.What exactly causes the circuit to break? I mean, what units should I concern myself with when buying a heater, --Watts or Voltage? Why does this...
  20. R

    Solar Water Heater: How It Works & Energy Transfers

    Hi good day to you all :) can anyone explain with some detail the principles on how a solar water heater works and the energy transfers. THANKS
  21. anorlunda

    Modifying My Boat's Keypad Module: Searching for a Heater Pad

    The chartplotter on my boat works fine. But the buttons work via a sealed keypad module. The contacts use (I think) a. Conductive grease. It works fine when the temperatures are 70F (20C) or higher, but not fine when it is colder. I'm fond of that device. I would rather modify it than...
  22. J

    Induction Heater - HalfBridge Series Resonance Circuit

    Hi All, I am glad to have found this site as it offers a great range of information. I have looked through similar threads before posting this and didn’t find anything that answered my questions. I am to build an induction heater(cooker type) using a half bridge series resonance circuit as a...
  23. enosis_

    Are you familiar with rocket mass heater design?

    Is anyone familiar with the so called rocket mass heaters - a popular DIY project? Has anyone ever studied design or uses?
  24. steves1080

    Thermostat controller for plug-in heater?

    I have a magnetic-mount heater (300 to 400 degF output) that I want to put on a pump that I wish to protect from freezing weather. However, considering that there are various components on the pump that are only rated up to 185 and 200 degF, I'd like to add some sort of temperature control...
  25. A

    Can an immersion heater reach 600 degrees Fahrenheit in a closed cylinder?

    I have a closed 4" diameter cylindrical vessel with Volume=400in^3 filled with air at room temperature. A 3500W immersion heater with Watt Density=23.9W/in^2 will be used to heat the air. Can the air get up to 600 degrees Fahrenheit? How can I find out what temperature the air will get to?
  26. T

    Water heater with element in the top section - bad?

    I've got a 300 liter water heater that has an electrical element (14 kW). The issue is that the element is positioned in the top third of the heater. I fear the water will become segregated so that only water in the top third will be heated, and the lower section will remain cold. The target...
  27. I

    Final air pressure in a heater

    Why is the final air pressure equal to the initial air pressure?
  28. G

    Nichrome wire heater optimisation

    Hi, I am designing a plastic recycler and I need advice on choosing gauge of some nichrome wire. I want the heater to reach around 220 degrees C and I will be powering it with a laptop charger (19v 7.1 amps). Temperature control will be achieved with a PID controller. The nichrome wire will...
  29. K

    Calculating Heat Absorbed & Estimating Power Rating of Electric Heater

    the question states exactly: Air passes over an electric heater at a steady rate of 2500 cubic centimeters per second. the steady inlet flow temperature of the air is 20 degree celcius and the steady outlet temperature is 40 degree celcius. part a. what is the heat absorbed by the air...
  30. R

    How Can a Flame Burn in a Closed Space Without a Fan?

    Hi Everyone, Hope this is the right section of the forum. I need some help to design a small tube heater for a specific application. I have attached a crude picture to show what i need. The flame needs to travel through a 3/4 inch pipe about 7 feet to heat the water. The problem is that i...
  31. C

    Electrical Home project - DIY Large Solar Pool Heater

    Hi all, I live in Perth, Australia and have just moved houses to a place with a relatively small pool, unfortunately it is shaded for the majority of the day by a big tree and it is quite cold and unwelcoming (unless you have built of a sweat). I want to make a solar pool heating system to...
  32. T

    PSU Power and Heat: Understanding the Relationship

    If my PSU is 800W and it runs at full power, does that equal a 800W heater standing in my room, or does just some of it turn into heat?
  33. C

    How does an improvised immersion heater made from confiscated items work?

    Heres is an improvised immersion heater that was confiscated from inmates in a German prison: that looks like the absolute bare minimum immersion heater and is clearly dangerous as hell but I'm wondering how exactly it works. Its connected directly to a mains plug so there will be 240V AC...
  34. V

    Struggling with Inline Heater Design

    I'm designing an inline heater for a coffee brewing project. My plan is to use an aluminum tube with Nichrome heater wire wrapped around it to heat the water flow. For brewing I need to dispense somewhere around 16 fl-oz per minute at a temperature of 205 F. I would like to determine...
  35. C

    Heat produced by thin film resistive heater.

    Hi guys. I am new to this forum and need some help in solving some problems. My company produce thin film heater( doped tin oxide deposited on a substrate such as glass ceramic, beryllium oxide, aluminium nitride or alumina and some others). I need a formula for calculating within a few degrees...
  36. T

    1500w electric space heater problem

    Homework Statement *An electric resistance space heater rated at 1500W for a voltage source of v(t)=120√(2) sin(2pi60t)V has a thermostatically controlled switch. The heater periodically switches on for 5 min and off for 7 min. Determine (a) the maximum instantaneous power, (b) the average...
  37. R

    Manual or automatic save power in water heater geyser

    Water heater geyser(15 lit) for bathroom. We use geyser from morning 6am to 11:30 am only. So which would save power keeping the geyser on automatic mode or turning it "ON" in the morning and turning it off at 11:30 am. I know for e.g if the temp is set to 60 deg, on automatic mode...
  38. R

    Does lowering the water heater geyser temp save power

    If a water heater geyser(15 lit) set temp is dropped down does it help in saving power. I open both tap hot water and supply water simultaneously to my bucket for bathing purpose only. So if the temp is set high(as set by the company), it will be needed less and therefore less water is to be...
  39. V

    Calculating Power of Outdoor Heater: A Puzzling Problem

    Homework Statement An outdoor heater has a resistance of 50 ohms and operates at 275 V. A transformer connected to a 120-V source supplies electricity to the heater. What is the power used by the transformer? Homework Equations P = V^2/R The Attempt at a Solution I plugged in the...
  40. N

    Transformer for Heater Control

    I am looking to power a heater. According to the product specifications it will require 11.1V/26.4A to heat to 800C and 16.9V/33.1A to heat to 1000C. The manufacturer sells an expensive temperature controller which we would like to avoid using. It has been suggested to me that I use a variable...
  41. T

    Calculating Thermal Energy from Passive Solar Heater

    This is for a physics finals project. So it's not really a homework question. But I didn't know where else to post it and I need immediate help. I have made a passive solar heater out of pop cans and I need to find out how much energy (thermal) is produced. I know the equation for thermal...
  42. N

    Hi all. Induction heater question

    Hi, new to the forum. Great place but much of the info far past my interlectual understanding. :frown: I have been looking at the idea of an induction heater for use in my job. I'm a mechanic by trade, nicknamed proffessor screwtop by my workmates :) Snap recently introcuced the...
  43. G

    Inefficient: A/C set @ <78 °F, heater set @ >68 °F

    "Setting Your Thermostat for Maximum Energy Savings" by Jeffrey Orloff claims that during warm months, setting an air conditioner less than 78 °F, or greater than 68 °F in cold months, is most efficient. Another page claimed that going down to 72 °F in the summer months can increase energy...
  44. O

    Power rating of a heater in the same outlet as a hair dryer

    Homework Statement A heater is plugged into the same 120-V AC outlet as an 800-W hair dryer. If the total rms current drawn is 16.7A, then calculate the power rating of the heater. Homework Equations Pav=\frac{1}{2}I2peakR The Attempt at a Solution Irms=Ipeak/\sqrt{2} So...
  45. D

    Building an Induction Heater for Steel & Aluminium

    Hi guys I'm looking to make an induction heater to heat bits of steel and aluminium (maybe 15mm by 25mm). Can anyone recommend a good source of information in terms of calculating the various parameters and other general information? I've looked at many websites but a lot of them seem to...
  46. P

    Building an infrared heater element

    So, as the title describes, I am trying to build an infrared heating element for my own heating panel. I want to use this heater to cure an epoxy at 350F that is about 5" away. I'm an EE so the wiring and such will be simple but the heating calculations are beyond my area of expertise. Here is...
  47. S

    Air passes over an electrical heater at a steady rate of 2500cm^3 per second.

    Homework Statement Air passes over an electrical heater at a steady rate of 2500cm^3 per second. The inlet temperature of the air is 20^oC ( 20 degrees celcius ) and the steady outlet temperature is 40^0C ( 40 degrees celcius) a) What heat is absorbed by air passing over the heater in 2...
  48. E

    Relays - Controlling voltage flowing for heater elements to maintain temperature

    So I have a UT130 Temperature Controller turning on and off a heater element through a SSR relay to maintain the temperature of water at a constant temperature. But the problem is that the temperature will still fluctuate making the relay go on and off continuously. I need the water to stay at...
  49. L

    Understanding a Sealed Container with a Heater & Fan

    Hi, I would really like some insight here, I don't know what I'm doing! also, sorry if i get the terms wrong and miss the obvious, this isn't my field. I will try to keep this short: I think that if you have a solid object, with a Heating element in the centre, and the surface in ambient...
  50. H

    Can You Use a Car Heater to Heat Your Home?

    car heater to heat house?? Hi everyone. So i had a brain wave and thought id put it out there for help or advice. I have just moved into a new house and thought id start looking into heating for the upcomming winter. I thought about buying a new 19 kilowatt wood burner to heat the living area...
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