Tag: Refrigeration

Rooftop Units explained – RTU working principle hvac

Howdy there, guys. Paul here from TheEngineeringMindset.Com. On this video, we’re going tobe discussing rooftop units. Arising, what’s anRTU, the place are they used, how do they work, the unique varieties, as well because the componentsinside, equivalent to warmness exchangers, filters, lovers, ductwork,grilles, air hoods, et cetera. For those who like the informationyou see on this channel, and that i fairly hope you do,then it can be handy to preserve your schooling going byheading as much as Danfoss studying who have kindly subsidized this video. Danfoss need to encouragepeople all all over the world to gain knowledge of as much aspossible about engineering. So that they developed a freeonline finding out platform packed full of publications onpretty so much every possible engineering matter,including extra classes about rooftop units.All you have to do to getstarted is click on the hyperlink within the video descriptionbelow, create your free Danfoss finding out profile, andthen opt for your top notch. Pop engineers quiz, what does a package airconditioning unit imply? Inform me your solutions inthe feedback section beneath, and i will expose the answerat the very end of the video. Ok, rooftop models, as thename suggests, rooftop units, or RTU for brief, arelocated on the roof of stores and small industrial buildingsto furnish air conditioning to outlined areas. These are packaged air conditioning units, and they are so wellknown becausethey are simple, compact, self-contained, all-in-one HVAC items. Their reason is todistribute conditioned air within outlined areas of a constructing.Rooftop items are linked to ductwork which provides a definedroute for the conditioned air to travel along. Now in our final video, we looked at air handling items, or AHUs. I would motivate you to watchthat if you haven’t already. Hyperlinks are within the video description under. When you’ve got watched that,you’ll as a rule detect that these models are very identical. Rooftop items are a style of air handler.The foremost difference is thatthey are ordinarily extra compact, and they’re at all times established on the roof. So they have to be morerobust and weatherproof to take care of things like solar,rain, snow, wind, et cetera. Additionally, AHUs will oftenbe connected to important vegetation similar to chillers and boilersto provide the heating and cooling, however RTUs are self-contained and have everything theyneed multi functional unit. That’s why they may be calledpackage air conditioners, and we are going to appear insidesome units just shortly to realize why. There are lots of forms of rooftop items, and we’ll look at fourdifferent usual versions starting with essentially the most normal. This first unit is freshair simplest so that signifies that there isn’t a recirculationof air occurring. It takes one hundred% fresh air and stipulations it. The return air is most often removedby an external exhaust fan to balance the air pressurewithin the building, but we is not going to duvet thatpart in this video.First, now we have the housing. This needs to look after all themechanical and the electrical equipment within the unitfrom the sun, wind, rain, snow, frost, et cetera. There can be some accesspanels constructed into this to enable engineers toaccess the accessories inside of and participate in protection. At one finish, there wouldtypically be an air hood. This is the place the outside ambient air might be drawn into the computing device. The hood is formed this way tostop water, snow, and debris from getting into into the unit. There’ll usually bea mesh throughout the inlet of the air hood which willprevent flora and fauna and objects from getting into, as thiswill purpose blockages and injury the fan. The following thing we mightfind are some dampers.Now not each unit has these, butnewer models commonly do. These are in actual fact sheets ofmetal which rotate together. They open wholly to allowair to enter the unit or they almost sealthe unit and prevent air from coming into or leaving. Some dampers can fluctuate their open function to someplace between fullyopened and thoroughly closed, mainly if recirculation is used, and we are going to seem at that later in this video after this basic model. After the dampers, we will in finding the filters. These will mostly just slideout from the provider door. Their purpose is to cleanthe air with the aid of shooting the dust and the dirt which iscontained within the incoming fresh outside air. If we would not have filtersinstalled, then the fan, warmth exchangers, mechanicalcomponents, and the ductwork are all going to slowlybe blanketed with the aid of the dirt, and it is going to curb the effectiveness and the efficiency of the computing device. If an excessive amount of dust buildsup on these add-ons, then it is eventually going to lead to the failure of the desktop. After the filters, we are going to have some coils. These coils might be usedto cool or warmness the air by using including or doing away with thermal vigor.Depending on the place in theworld the RTU is placed and the ambient stipulations it faces, some models shall be cooling most effective, although infrequently theywill be heating most effective, and a few can be heating and cooling. If the unit is cooling simplest,then it could by and large have a single coil which is connectedto a refrigeration unit. If the unit is heatingonly, then it will both be related to a heat pump, a fuel burner, or an electrical heating aspect. If unit is heating andcooling, then it should both have two warmth exchangers, whereone might be a cooling coil which is attached toa refrigeration unit, and a good way to provide the cooling, and the opposite will likelybe a true warmness exchanger which is attached to a gasoline burner, or it might be an electricalheater to furnish the heating.However, a unit mightprovide each heating and cooling making use of a single coil whichis connected to a warmness pump. Now we have blanketed heat pumpsin a prior video. Hyperlinks for which are in thevideo description below. Most models will use a refrigeration approach to furnish the cooling. The compressor, condenser,fan, and controls are most likely placed on the rearof the unit or at the facet, and these will likely be used toreject the heat and hold it faraway from the intake and the conditioned air which is inside the unit.After the coils, we will to find the fan. That is by and large a belt-drivencentrifugal sort fan, but it surely can be an EC type fan that are more vigour effective. The fan pulls the air in from external then by means of the dampers, filters, coils, and they will push thisthrough the ductwork to be dispensed around the constructing. That’s our most basictype of rooftop unit. So what else might we discover? Some models mightrecirculate the interior air for a return ductwork procedure. This is used to saveenergy, primarily in winter when the external air may be very bloodless and a return air could be very heat.We can use this to reducethe heating load through mixing one of the crucial heat return air in with the cold fresh air consumption. In this design, we discover areturn air damper within the unit. This may work in syncwith the intake air damper and the two will range theirposition to alter the blend of how much contemporary airand how much return air is passing through the unit.There will constantly be acertain amount of recent air coming into into this typebecause or else the constructing would without difficulty refill with CO2 and create an extraordinarily unhealthy atmosphere. Because the damper opens, thesuction of the fan will pull air in through the ductwork. When the damper closes,no air will be drawn in. A different version we will come across, and this sort may be very long-established,in this design, we again have the return air damper, but this time one of the vital air or all of the air will also be rejected to atmosphere. The temperature of theoutside air and the return air and mostly the CO2levels of the return air will dictate how much air might be rejected and how much will bemixed and recirculated. On this form of unit, whenthe outside air temperature is beneath or practically thedesired indoor air temperature, one hundred% fresh air can beblown into the building, and none of it is going to be recirculated.All of it is going to be rejectedas the cooling demand is met. That is referred to as free cooling cycle or an air facet economizer cycle. The ultimate variation we’lllook at has a warmness wheel built into the unit. This is developing in popularitywith the growing want for energy effectivity inbuildings to slash CO2 emissions but additionally vigour and utility expenditures. This unit first pullsair in through the hood. The amount of air enteringis controlled with the aid of the damper. The air then passes througha filter to capture the dust and the dirt and preserve thesurface of the warmth wheel. It will then pass by way of the heat wheel. The warmth wheel is a rotatingheat exchanger which picks up the waste warmth or CoHP fromthe return discharge air, after which switch this overto the incoming contemporary air with out the 2 air streams mixing. These warmth wheels arenot entirely airtight. So a bit of bit of air mixing will occur. The warmth wheel is usedto offset the heating and mostly cooling demandwhen conditions are right.This may increasingly keep vigor,as good as utility bills. After the warmness wheel, the air flows by way of to another filter. Simply earlier than the filter, we have now a damper on the return air circulation. This permits us to recirculatesome of the return air into the fresh air,and the quantities range by utilising the dampers. Not all warmness wheel RTUswill have this feature. Some will use only a hundred percentfresh air consumption and extract. If the unit does not havethe choice to recirculate, the unit commonly will nothave a 2nd filter again here. After this, the air will flowthrough the warmness exchangers so we can warmness or cool theair to the desired temperature.The fan will then distributethe air via the building by way of the ductwork to thedesignated areas. The return air is thenpulled back into the RTU for the return ductwork. Once it re-enters theRTU, it has the alternative to both recirculate one of the vital air back into the contemporary airintake, or else it’ll all cross by means of a filter andthen by way of the heat wheel to recapture the waste warmth. After the warmth wheel, wemight find an extract fan.Otherwise, the pressurecaused with the aid of the most important deliver fan will drive the air out in some designs. The air then passesthrough the extract damper which is used to differ thevolume of return air mixing as good as the pressureinside the building. After that, it passes througha grille which simply stops objects and flora and fauna fromentering into the unit. It will then be ejected fromthe method into the atmosphere. Alright, before we wrap thingsup, I just want to remind you to signal up on your freeDanfoss studying profile. Doing so, will get you accessto over 1,500 e-lessons including a couple of about rooftop units. Go supply it a are attempting now. Links are in the video description below. Engineers quiz answers. On the establishing of the video, I requested you what does the term packageair conditioning unit mean.The answer is that packageair conditioners incorporate all of the predominant add-ons inside one casing. So that is the enthusiasts, thefilters, the cooling and heating coils, the compressors,the controls, et cetera. The entire approach isprefabricated into one package deal. It comes from the brand, and will also be speedily established as one unit. Ok, guys, that’s it for this video. Thanks very so much for watching. I hope you enjoyed thisand it has helped you. If that is so, then please don’t forget to like, subscribe, and share, and leave your questions inthe comments section beneath. That you would be able to also follow us onFacebook, Instagram, Twitter, and TheEngineeringMindset.Com. Once once more, thanks for staring at.

Portable Air Conditioners – Why you shouldn’t like them

Air conditioners are beautiful cool. *awkward pause* however theres an increasinglypopular style of them that figuratively and actually sucks. That will be… These bundles of joy. Portable air conditioners appear to be takingthe world by using storm, or at the least have taken the air conditioner isle of the hardware storeby storm. But are they any just right? Do these cold-making machines have what ittakes to usurp the usual window unit? No. Moveable air conditioners are absolutely kinda bad. Now its not like they dont work! And some of them arent relatively as bad asmost. Plus, they may be able to particularly come in helpful. This one right here is serving responsibility exactly becausethe window its venting through isnt really acceptable to protecting a window unit inplace with any feel of confidence.And i do know considering that i attempted. Sure, this right here is the logo of my disgrace. The air conditioner that was once never meant tobe. But fortunately for you I didnt return it becauseits gonna be a excellent visible aid! Now, in this video Im going to argue thatif you want an air conditioner you must gravitate closer to these simple window unitsand faraway from those modern portable units *if you could*. And to find out why, we have got to be trained a littlebit about air con. Air conditioners are mechanical gadgets whichcollect and concentrate heat power so as to move it from one position to a further. The cold air they invent is in fact ordinaryair thats had its warmth energy sucked correct out of it.And of path, we cant simply bottle thatenergy up (although that might be tremendous cool if we might determine that out) so as a substitute wemove it someplace else–traditionally to external air. And within each air conditioner youllfind three predominant ingredients that make that occur. This is the basis of almost each air conditioningand refrigeration process in service in these days. The black cylinder involves a compressor whichsqueezes a gas referred to as a refrigerant right into a small area, reducing its quantity and increasingthe stress its under. The excessive strain fuel, which has now gottenquite hot due to the fact that it simply obtained compressed, travels by means of these pipesinto the 2d key factor; the condenser. The condenser is a warmness exchanger designedto cool that hot gas down as swiftly as possible. The densely spaced fins expand its surfacearea to pace up the heat switch, and a fan helps to speed it along even more by way of blowingair throughout the fins. When you consider that the refrigerant is now pressurized,its boiling factor has accelerated. And correctly, its boiling factor has increasedso so much that once we get it down to some thing like one hundred thirty or 150 levels, it is going to condenseinto a liquid.So, because the sizzling fuel winds its way by way of allthese pipes and its warmness power gets transferred to the air, it slowly turns into a liquid,releasing a ton of heat power because it does so. Now heres where the magic occurs. That liquid is being held back by way of a meteringdevice reminiscent of a thermal growth valve, to keep the stress excessive within the condenserand limit the quantity of liquid refrigerant that can move by way of. This normal air conditioner makes use of a capillarytube, a protracted copper tube with an extraordinarily small internal diameter, to restrict the refrigerantand accordingly restrict its float.But as soon as it makes it by means of to the otherside, it finds itself in a 2nd warmth exchanger, referred to as the evaporator. This one is functionally equal to thecondenser, except the strain inside of right here is far, so much curb thanks to the suctioncreated by using the consumption aspect of the compressor. As soon as inside of right here, the refrigerant can loosen up,and its boiling point all of the sudden shoots method method down, like into the good-below-zero territory. And that implies its gonna spontaneouslyboil –or evaporate– seeing that, well, its too scorching for it to remain a liquid. But to change phases again into a gas, it needsto get energy from someplace. And luckily, the fins of the evaporator helpit soak up the power in the room, and the outcome is that the room will get less warm.In outcome the warmth energy throughout the roomis being used to heat up the refrigerant as it evaporates. Fascinated by this can also be kinda weird becausewe prefer to think of the evaporator as getting cold, which it is, however its getting coldbecause its pulling heat vigor out of the air and into the refrigerant within ofit. Coldness is particularly just less concentratedheat vigour, and on the grounds that warmth likes to head towards bloodless places to unfold out, it naturally findsits method (with the aid of a fan).After the refrigerant has absorbed as muchenergy as it will probably, it reenters the compressor where the cycle starts in all places once more. As soon as its underneath high pressure, it’ll beable to condense into a liquid again, releasing the energy it just absorbed to the outsideair through the condenser. Now, I dont need to get too far into thephysics of how this works, nor talk about what makes refrigerants distinct and why theyhave been and proceed to be a notoriously complex set of chemicals to control, so allI rather need you to know for this video is theres a compressor, a sizzling part, and acold aspect. If were cooling a room, we wish the hotside external and the cold part inside. Then we can transfer the warmth power from insidethe room to the external air, cooling the room. So, lets take a seem at where these componentsare when the window unit is in operation. When resting in a window, the bulk of themachine is in reality external of the space its cooling. The compressor and condenser are both outside,and due to the beneficiant amount of styrofoam insulation, we get an exceptional thermal barrier.When cooling, not one of the exact air in theroom is moved outside–best the refrigerant, and for this reason the warmth power its absorbed,makes it out. This maximises efficiency. If you have a important air conditioning system,you most often have whats known as a cut up method. Right here, the compressor and condenser (alongwith a cooling fan) are contained in a single unit which sits external, and copper refrigerantlines are run into the constructing to a separate evaporator located in an air handler or incorporatedin a furnace. See? Its a cut up approach, because the evaporator andcondenser are break up apart. These techniques are incredibly efficient, with theentire hot aspect placed outside and far from the living space, and simplest a tiny hole isrequired within the properties thermal barrier to move the refrigerant in and out.Very well, and now lets take a appear at aportable air conditioner. You may become aware of that the complete computer isinside. That implies not only is the bloodless part within,the scorching part is inside of, too. Well. Thats now not first-rate. We would like the vigor being absorbed via the evaporatorand launched into the condenser to make its approach outside by some means. So, what to transportable air conditioners do? They suck in indoor air by way of these vents,blow it across the condenser to cool it off, and then push it outside via that hose. That last sentence could be very major. They pull in air by way of these vents, air that they simply cooled, intellect you, and blow it outside. That sounds pretty friggin silly, just onits face. Now, its not adore it doesnt work. If these didnt work they wouldnt benearly as wellknown as they’re. Additionally! Two-hose transportable air conditioners, whichsuck in *external* air to cool the condenser after which blow it back out in two separatehoses, are on hand, however they’re an more and more rare part of the portable air conditioneruniverse and the substantial majority on sale are single-hose models identical to this one.So, if this computing device depends on drawing airin through these vent slots to cool the condenser, and then has to barf the now sizzling air outside,that means not simplest is it sacrificing one of the vital cool air it simply generated, itsalso making a low pressure environment in something area its in. Now the air pressure external room is greaterthan the within. And that signifies that external air is going tomake its way in via the walls to refill the air that simply left. You cant simply expel air from a room withoutit getting changed by hook or by crook (in any other case youre in a vacuum chamber and i recommend you depart as quickly as feasible). And what replaces it’s eventually the hotoutside air that youre combating towards. Genius! And as a result have been at the core of this dilemma.Single-hose moveable air conditioners willalways be tremendously much less efficient than a window unit since theyre not simply pullingthe warmness vigor out of your room. Theyre additionally pulling the air out, too. In fact, for those who go to a hardware store andtake a appear at a fresh assortment of moveable items, youll frequently in finding that they havetwo cooling capacities listed in this day and age. Why? Well, when you consider that more recent testing ways are accountingfor the losses brought about via this hose, so whilst the unit could technically be ableto move eight,000 BTUs per hour, due to the nice and cozy air its drawing again in (as good asits possess cold air its blowing again out) its without difficulty simplest moving 6,000 BTUsper hour. So, truly its 25% much less efficient. But its without a doubt so much worse than that! This little 5,000 BTU window unit consumes455 watts. If we take a look at this 5,500 BTU portableunit from LG, youll see that it uses over a kilowatt! Thats greater than double the input powerrequired to generate handiest 10% more cooling.A window unit that consumes that much powercan produce roughly double the cooling capacity. So yeah. Eek. Now Im not here to say that these are terribledevices and youre a fool if you possess one. Intent identification be calling myself a fool twiceif that have been the case. However i’ll say that most likely, these shouldbe your final motel. If in case you have the alternative to make use of a traditionalwindow unit, take it. Its far more power efficient and it willcost less to run. And yeah, I get it. Theyre ugly. They block your view from the window. Theyre no longer precisely attractive from theoutside either. But its not simply power efficiency thattheyre higher at. Air conditioners are noisy. Theyre noisy given that theyre mechanicaldevices, with a buzzy compressor and two droning fans moving air around. With a typical window unit, the compressorand one of the most two fanatics are external. Due to that thermal insulation, you geta lot of sound insulation, too. Youll undoubtedly become aware of a change whenthe compressor is on versus when its no longer, but its more often than not beautiful refined.Exceptionally for the reason that, as is the case for manywindows items, the identical motor drives the indoor blower fan and the condenser fan, so the onlypart that cycles on and off is the compressor. [sound of fan running] [sound level increases slightly as compressor kicks in] And of direction, split techniques are even quieter for the reason that the loud elements are nowhere near theliving space. [compressor and fan switch on] evaluate that to this factor. No longer handiest is the compressor now within theroom youre looking to work or sleep in, however so is the condenser fan. The effect is that its now not that noisy whenits handiest going for walks the circulator fan. But when its thermostat calls for cooling,it will get means, way louder! Suddenly, the compressor kicks in (which again,is throughout the room) and a 2nd fan activates to expel the warmth from the condenser. Its a good thing the condenser fan shutsoff when its now not actively cooling, as or else it will suck even more air out the room.But it manner theres a stark differencein noise levels between now not cooling. [a moderately quiet fan noise] And cooling. [compressor kicks in, and a second, much louderfan spins up at the same time] [it’s really quite dreadful] And if youre trying to sleep in the sameroom as one of these, youll ought to put up with it going from lovely quiet to loudas hell and again again and again. This can be a inexpensive in-house manufacturer unit from thatplace where you retailer gigantic money so I wasnt anticipating it to be whisper quiet, however Ivealso got a extra appropriate unit from LG that, whilst a little extra dependent in the way in which ithandles the transition from cooling to no longer cooling and vice versa, remains to be so much muchlouder when its cooling.[fan noise] [a second fan spins up] [compressor kicks in] Im a pretty heavy sleeper, and even for me it can be a project to ignore the thingand go to sleep. And a further thing to recollect is that whilewindow units steal a better chunk of your windows, they dont steal your flooring space. Transportable items arent small and they cantsit flush towards the wall thanks to the hose, so be all set to re-organize slightly furnishings. And by the way. That hose? It will get scorching! That warmth energy it just centred isntgonna go away with out a battle, and due to the fact that this hose isnt insulated at all, some if itis coming proper again into the room. First-rate. But, in poor health admit. Transportable A/C items are helpful. Fairly handy. They dont need proper set up likea window unit does (which is really a ache, I would add).They may be able to with no trouble be moved from room to roomthanks to the wheels theyre on (thats why the call them moveable). And they match window types that might otherwisebe unable to accommodate an air conditioner, comparable to vertical home windows or even patio doors. You could even run them by way of a small committed vent, if you choose. But sadly, their single-hose design makesthem, honestly, a horrible device when it comes to efficiency. Id like to peer more double-hose units availablefor sale. Theyre still gonna have the noise and floorspacedisadvantages, however they as a minimum regain much of their effectivity back. Last year i attempted a transportable mini-split system,with a separate outdoor compressor and condenser unit, and an indoor evaporator unit connectedvia a flexible refrigerant hose. Lamentably, my unit had a refrigerant leak andstopped working after just a few weeks. It appears like thats a usual drawback, butlet me let you know it was once blissful whilst it worked. Quiet, efficient, and amazing.Identity like to see this product get extra development,however I also fully grasp that its acquired way more barriers than even a window unit. Until you need to get inventive with somesort of exterior wall bracketing, that is constrained to a floor-ground room or a room witha balcony or anything identical. But anyway. If were gonna keep using these matters,will we please get more dual-hose models? I get that theyre less bendy, particularlywith vertical or narrow windows, and so are commonly less fascinating, however hopefully withmore people conscious of the vigor losses triggered via regularly pushing the air out of yourhome, well see multiplied demand. Nonetheless, if youre looking for an air conditionerin a concern where a window unit could work–youre severely at an advantage going with the windowunit. Contrary to what you would suppose, portableunits are absolutely now not an upgrade. Rather then their portableness. Thats, thats lovely cool. Thanks for gazing, and i’m hoping you foundthis video to be as cool as a accurately charged air-con approach. I do want to discover air conditioning a littlemore for the reason that I find it exciting.The best way that we take advantage of the physical propertiesof designated gasses to make heat energy move where we want it to go is kinda intellect-blowing. Oh, and by the way, no longer all refrigerants arecrazy problematic chemicals. Some small refrigerators and air conditionersare opening to be charged with propane. Propane, often referred to as R290, is becoming anincreasingly fashioned refrigerant due to its abundance and relative environmental harmlessness. Regrettably its additionally flammable whichmakes servicing these a bit of complicated, and makes it unsuitable for bigger models whichneed a variety of refrigerant. However principally for small, cheap models likethese matters which are likely to effortlessly be disposed of once they die rather than actuallyserviced, its a first-rate possibility to make use of it.This computer, though, even as it is chargedwith a flammable refrigerant, uses difluoromethane, or R32. Of direction, thanks to everybody who supportsthe channel on Patreon, with a special thanks to the satisfactory humans you see scrolling up yourscreen. If youd prefer to become a member of these humans in supportingthe channel, theres now a new perk! All shoppers have access to the patreon-onlyTechnology Connections Discord server. So, if Discords your jam, you can jointhese other folks with the aid of linking your Discord account to your Patreon account. And as continuously, early video entry, occasional(very occasional) in the back of-the-scenes movies, and other patreon-best stuff is availableto you as well. Thanks for your consideration, and Illsee you next time! Icy delicate jazz …The cold air they devise is actually ordinaryair, eh.Eugh, eugh blaugh ugh. Im–this tone is all flawed. Good enough possibly transfer at like a p.C. That makessense. Yeah, thats written fallacious. Good, thats exceptional. And now i will document that line as written! Or at least have taken the hardware isle ofthe air the hardware! Arghh nope. Air conditioners are nois I should transfer this again. Coldness is rather just much less concentratedheat energy, and sint he Augh! Sint. In view that warmness! Because warmth! Its a wo…The due to the fact! Due to the fact is the word. Due to the fact..

HVAC Engineering Technology program (HET) at CLC

Our HET program is designed to teach thestudents anything dealing with heating, cooling, ventilation or airconditioning. We have high school students coming in, and we have peoplecoming into our program to change careers. They will start out with verybasic circuits, working with series, and parallel type circuits, and then work upinto a complete heating cooling system. The skills they can build up and leadinto can be anywhere from very basic, from working on houses to working inindustrial buildings. We have very high tech equipment from high efficiencyheating and cooling units. Wireless digital type controls. So they’re gettinghands-on experience as they would find in the field. What they love of ourprogram is the hands-on portions of it. Not many schools in the country havewhat we have here.One of the greatest things about the HVAC program is thatit’s a growing field. People can come in to field and expect to leave with the skillsto be able to make an income, they could take care of family. Our tuition isextremely low and most our instructors have over 20 years in experience. Theway our program is built is that we have stackable certificates and each one ofthose certificates will step right into a AAS degree.If I could say one wordabout this career, it would be life-changing..