Youtube daily Apr 16 2018

hey there guys Paul here from the engineering mindset calm in this video

we're going to be looking at data center HVAC we will focus on the cooling

systems used we'll compare how the different strategies work and how to

improve the efficiency especially with a new growing trend of using computational

fluid dynamics or CFD software and we'll also run some simulations to show just

how powerful this is data centers are rooms of computer servers which provide

networking and internet-based services they range in size from a small single

room serving a single organization and they scale all the way up to enormous

Internet giant's such as Google and Facebook more and more data centers are

open each year as we use and increasingly rely on the Internet and

remote services the store access and stream our data with this growing trend

is important that the building's run as efficiently as possible as the data

centers are operational 24/7 they can consume vast amounts of electricity and

as this electricity is used the power of the servers and process all the data it

generates a lot of heat this heat needs to be removed otherwise the electrical

components will overheat and fail or even catch fire the energy consumption

for a typical data center will be split of around 50 percent being used by the

IT equipment 35 percent on coding and HVAC 10 percent on the electrical

infrastructure and support and around five percent on lighting the electrical

demand for data centers really does vary from just a few kilowatts up into the

megawatts depending on the size and the location so we're going to look at a few

examples of data centers and their air-conditioning systems as well as the

efficiency improvements that can be made the first part will briefly cover is the

non data whole areas these are the areas where staff are normally located the

security guards the engineers and technicians etc and these cover the

areas of the offices the toilets the workshop and rest areas these areas will

be served by a separate mechanical ventilation system and will use either

an air handling unit or a rooftop unit to distribute conditioned air to suit

the thermal comfort needs of the humans they might also use a separate split

unit heat pump of a RF system for temperature control in these areas I

won't go into too much detail in this segment as we've covered these in our

previous videos on chillers I hate use are to use we also have videos on vrf

heat pumps and split if you want to learn more on these links

are in the video description below coming over to the server room one of

the most common methods currently used is to place the server racks onto a

raised floor and then use computer room air conditioners or crack units to

distribute the conditioned air to the server racks the crack units have heat

exchanges inside which are connected to refrigeration units or chilled water

systems to remove the heat from the server racks some can also humidifier or

dehumidifier the air that's very important in order to control the static

electricity in the air they have filters inside to remove dust

from the room as well as a fan to circulate and distribute the air for

extra efficiency the crack unit should use energy-efficient filters EC or

electronically controlled fans and pressure sensors in the floor void to

precisely control the air supply rate placing temperature sensors on the

intake grilles of a server rack is often recommended to control the supply

temperature up from the crack units as this matches the actual intake the

conditioned air will be forced by a fan in the crack unit into the void under

the floor and the small holes of grilles in the floor tiles will allow the air to

leave the void in strategic places this air will collect the heat and rise up

towards the ceiling the crack units then suck this warm air back into the unit to

be reconditioned in the early days the server racks were positioned facing

different ways and engineers soon realized this was very inefficient

because the fresh cold air was just mixing with the warm discharged air of

the servers and this meant that the server's were receiving different air

temperatures some hot some cold and this led to higher energy consumption as well

as a high failure rate of the server's to combat this the servers were

positioned so that all the server racks were facing the same way this was a

slight improved strategy but quite often some of the discharge air was being

pulled into the intake of the server exiting behind it which led to mixing

and an increased air temperature the next strategy used which is still very

common today is the use of hot and cold aisles this is a great improvement on

the previous designs because it separates the fresh cold air stream from

the hot discharge air the cold air rises out from the floor grills and is pulled

through the servers all the hot discharged air collects into the hot

aisle and rises up towards the ceiling what is then pulled back into the crack

units this means the server's should receive

only fresh cold air and the crack units received the hot discharge air this

increases the temperature differential across the crack units heat exchanger

and that will improve the efficiency of the machine this is not perfect however

because there will still be some mixing of a hot and cold air streams cutouts on

the floor can result in air leaks this means that the cold air can leak

straight into the hot aisle floor grills which are too close to the crack units

result in air recirculating straight back to the crack unit and will mix with

the returned Airstream gaps between the servers can result in air recirculating

around inside the south rack this can easily be solved though by installing

blanking plates if more cold air is supplied than needed it will flow over

the units and mix with a discharge line if insufficient cold air is supplied

then warmth discharge will be pulled over the top and around the side of the

server and into the cold air and will mix with the stream we're going to look

at some CFD simulation examples shortly of this occurring a much improved design

and one it is very popular calorie for both new and existing date centers is to

use a physical barrier to separate the two air streams there are a couple of

ways to do this we can use a barrier around the server rack and then contain

either the hot air or the cold air cold air containment is a very popular choice

for existing data centers that's because it is easy and cheap to implement which

means that payback is quick the cold air feels a cold aisle and then the hot

discharge fills the rest of the room with a crack units pulling this in for

reconditioning however it does also mean that any equipment located outside the

cold zone will only receive hot air the other containment strategy in use is the

hot aisle containment this is best suited to new builds as it cost more to

install in this strategy the cold air fills the room and the hot discharged

air is pushed into another void within the ceiling the intake for the crack

unit is also ducked into the ceiling to pull this hot air out for reconditioning

the hot aisle containment provides superior performance and also allows a

slight buffer for cooling should the power or cooling system fail we can

actually compare the performance of different server room setups quickly and

easily using CFD or computational fluid dynamics these simulations on screen

were generated using a revolutionary cloud-based CFD and FAA engineering

platform by since Cal who have kindly sponsored this video you can access this

software free of charge in the links the video description below and there

are for a number of different account types depending on your level it's not

just limited to data center design it's also used for HVAC AEC electronics

design as well as thermal and structural analysis

just a quick browse on their website and you can find thousands of designs for

everything from racecars heat exchangers pumps and valves which can all be copied

and uses templates for your own design they also offer free webinars courses

and tutorials to help you build and run your own simulations if like me you have

some experience with creating CFD simulations then you'll know that

normally this kind of software is very expensive and you would also need a

powerful computer to run it Sims cour whoever can all be done from the

internet browser and as their cloud base their servers do all the work and we can

access our designs from anywhere which I'm really pleased about as it makes our

lives as engineers and a lot easier so if you're an engineer a product designer

a student or a hobbyist then I highly recommend you try this out get your free

account by following the links in the video description below ok so the first

design we've used a standard hot I'll configuration the arrows indicate the

direction of flow and the colors indicate the velocity you can clearly

see there's a huge amount of recirculation occurring between the

hours and I've highlighted these in the boxes the second design uses partial hot

oil containment with the third hot oil at the end being uncontained you can see

the first hot oil has a very good profile and no recirculation is

occurring the second oil however there is some recirculation occurring towards

the end of the row so some steps like blanking plates need to be installed

here the third hot oil has some major recirculation occurring and that's

because there is no physical wall to separate the hot and cold air streams if

we then run a simulation for thermal analysis of the designs we can compare

the two designs and show the resulting temperature distribution at different

levels the simulation starts at floor level and moves up to the top of the

racks from the comparison we can clearly observe that at the lower levels the

second design has a much cooler cold aisle as compared to the first design

as we move to the upper levels the air temperatures start to mix but the second

design still maintains much cooler levels well below 28 degrees Celsius or

82 degrees Fahrenheit whereas the first design has temperatures above 29 degrees

Celsius or 84 degrees Fahrenheit the recommended ranges from standards

require that the inlet air temperature be within 18 to 27 degrees Celsius or 64

to 80 degrees Fahrenheit at the very top levels the temperature for the first

design are now in the hotter range of 40-plus degrees Celsius or 104 degrees

Fahrenheit or the second design the partial containment one has only a

maximum of 30 degrees Celsius or 86 degrees Fahrenheit thus the second

design performs much better in this case and further design improvements such as

full hot aisle or cold aisle containment can be studied using cloud-based CFD to

improved a center cooling as well as optimizing energy consumption of both

the server equipment and cooling units another type of data center design which

is becoming increasingly popular is free and evaporative cooling it can be

retrofitted in some existing designs but it's especially popular with large new

purpose-built data centers like Facebook and Google some of these new designs do

not use any refrigeration equipment for cooling this can only be done in some

regions of the world where ambient conditions are right but it allows

datacenters to cool their servers without any refrigeration plant the

ambient air is sucked into the building through some louvers and is then heavily

filtered and cooled and humidified by evaporative coolers and then forced into

the data hauled into a hot oil configuration the exhaust of the hot air

is then connected to another set of fans which pulls the hot air out and

discharges this off into the atmosphere some other cooling strategies which are

slightly less common are the use of doubted systems with heat wheels or heat

exchangers fitted these are our thermal energy to be transferred from one stream

to another without introducing fresh air into the building the fresh air can

contain dust moisture and salt particles which deteriorate the service electrical

components to provide cooling to the crack units you usually find a chilled

water system using a traditional chiller depending on the location some systems

are able to turn off the tears and use just the evaporative cooling capacity of

cooling towers for normal operation then use the chillers as their backup if the

cooling towers are unable to reach the setpoint some crack units contain their

own small individual refrigeration system which ever uses a remote dry air

cooler or they dump their heat into a condenser water system if a condenser

system is used then you'll often find a free cooler connected to the system or

sometimes built into the chillers this allows the heat to be removed without or

with minimal use of the compressor using just the fans to blow cooler ambient air

across the condenser which removes the heat okay guys that's it for this video

thanks for watching don't forget to sign up for your free sim Scout CFD account

using links in the video description below also you can follow us on Facebook

Twitter Google+ and Instagram links are below once again thanks for watching

For more infomation >> Data Center HVAC - Cooling systems - Duration: 11:47.

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The Results Of 12th Bhava In Various Positions | Yoga Manjari | Jyothisham Vaidyam | Astrology Uses - Duration: 25:14.

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Entitlement - House Cleaning Customers Acting Entitled - Duration: 9:06.

Entitlement.

What do you do with a customer who thinks they are entitled to cancel on you at the

last minute and to switch your schedule around and to throw things at you at the last minute?

We're going to talk about that today.

Hi there, I'm Angela Brown, and this is Ask a House Cleaner.

This is a show where you get to ask a house cleaning question,

and I get to help you find an answer.

Now today's show is brought to us by MyCleaningConnection.com

And in the resource section, there's a book that I want you to read, it's called

"You're Not So Smart" by David McRaney.

Now we're going to talk a little bit about why you're not so smart today.

All right, this question comes from a house cleaner who is furious, she's upset, she's

irritated, she's aggravated and she's frustrated with entitled customers who think that they

are above everyone else.

They treat the service or throughout help like they are lesser than.

She wants to know where on earth does this come from, and how am I supposed to deal with

it as a professional house cleaner?

Well that is an excellent question, and the answer is this.

There is a whole society that thinks that they are better than everyone else and they

are special, and the rules don't apply to them.

They walk into stores and they demand attention and they demand help, yet they are no different

than any other customer.

We have customers in house cleaning, they demand special attention, they demand special

projects, they expect that they can cancel at the last minute and that you're going to

automatically rebook them to the following day, or whenever it's convenient for them.

Now the truth of the matter is they're not so special.

They're just like everyone else.

If you have a roster of 40 clients and all 40 of them think that they are entitled,

then guess what? You have a small problem.

But yes, that's the society that we live in.

Understanding that that is the society that we live in, you have a couple of options.

As a house cleaner, you have an option to create some boundaries and to let customers

know that are only able to do so much.

When you are dealing with a customer that is entitled and they think that they're better

than everyone else, they think the rules done apply to them, and so if you ask them,

"What do you think is fair?"

They can't come up with an honest answer because fairness suggest equality.

It suggests that we are all equal, and I have to take my turn in your schedule.

That's not what they're wanting.

What they're wanting is you drop what you're doing and you come over when it's convenient for me.

You can't run a business that way.

From the very beginning, you have to set the ground rules and you have to say, "I am only

one person, therefore I have to work on a 24 hour schedule like everyone else.

After 5:00pm, that's time for my family, and so I don't take business calls after 5:00pm.

But I work from 7:00am until 5:00pm every day, and these are the available slots that I have open.

Which slot would you like?

When you chose a slot in my schedule, I respect your time enough that I will honor that particular

window every single time, on a schedule."

Now the key word here is respect, because people that are entitled, what they're asking

for is this, "I want to feel important.

I want to be special.

I want you to respect me," and so by them throwing things at you, all of a sudden, what

they're saying is, "I don't respect you, and I don't respect everyone else.

I expect everyone else to cater to my schedule."

If you cave in to that, what you're doing is you're saying, "As a house cleaner, I don't

respect myself, and I don't respect my other customers, and because you manipulated me

and you pushed me around, therefore I will cave into your crazy whims."

When you enable that behavior, it then gets repeated.

From the very beginning, you've got to lay out the ground rules and say, "I respect you

upfront, therefore I'm going to reserve this time slot for you, and I'm not going to let

anyone else push you out of that time slot.

However, out of respect to my other customers, you don't get to push them out of their time slot either."

You set the ground rules from right up front, and you let them know what the rules are.

Now if they call and they cancel, and they say, "Hey, I want this time slot tomorrow.

Something came up," I'm sorry, then you lose your time slot for the next two weeks,

until your time slot rolls around again.

Don't try to fit them into another time slot, because again,

then you are enabling that entitled behavior.

Now if there's some unusual reason, and you might have to bend that rule or break that rule

okay, do it on a case by case basis, but for the most part across the board,

the rules are the rules.

Here's the reason why.

If you have a wait list, and if you work that wait list, you're going to be able to fill

up that time slot very quickly, but what you're doing is you're telling your customers that,

"I play by the rules.

I'm fair with everyone, I treat everyone with the same respect,

therefore I'm able to run my business."

Now, the beauty of it is this.

As you expand your business, as you grow your business and you add employees, and you follow

those same rules, those are the rules that your company has established.

By following the rules, and by setting the rules in place for every single person, what

happens is you avoid people pushing you around and pushing you into that, I'm so special,

you should treat me differently space.

I have a friend whose son is in prison for a vehicular manslaughter because he thought

the rules did not apply to him.

He thought he could hop in a vehicle and drive while intoxicated, and the rules did not apply to him.

He has the rest of his life to think about how the rules do apply to him.

Now the truth of the matter is this, this is a really sad, scary moment and I want you

to think about this, all of the rules do apply to you.

They do.

It's the reason that we have speed limits, it's the reasons that we have red lights.

If you run a red light, you might get in a car accident, it's going to smash up your car.

The smashing up of your car, it doesn't make you special, it doesn't make you different,

you broke a rule, there was a consequence.

If in that accident, it's deemed your fault and someone else dies, yes you go to prison

for the rest of your life for vehicular manslaughter,

because you didn't think the rules applied to you okay?

There are so many things that come back to the concept of your not so smart.

I love this book.

I stumbled on it a couple of weeks ago and I read it from cover to cover, and it hit

me that as a society, we do, we think we're smarter than everyone else, yet we are just

like everyone else.

We forget our car keys, we turn our clothes inside out on accident, there are things that

we go to do, and we get in the other room and we can't figure out why we're in there.

We're not so smart, we're just like everyone else.

We're not entitled to anything.

When you have customers that come to you and they think they're so special, okay, what

you can do is this, you can treat them like hey, you are special, and because you're special,

I respect your time.

I'm going to put you on a regular schedule.

I'm going to bring my supplies every single time.

I'm going to collect a paycheck every single time.

They don't get to delay their payment because they're so special.

That's not how it works.

If they delay their payment and they don't pay you on time, the rules are well, then

I give your slot to someone else.

Because you didn't respect my process, I gave your respected, coveted spot to someone else

who's willing to pay.

Very quickly you've established the boundaries that you don't get to push me around.

It's not being mean, it's not being ugly, it's running a business.

You have to create, every quickly, upfront, we don't tolerate bullies, we are not harassed

by our customers, we are in business because we love what we do.

Because we love what we do, we're going to go out of our way to make you feel special.

We want you to feel like a million bucks and we want you to be pleased with the job that

we're going to do, but in order for us to provide that to you, these are the ground rules.

By having the ground rules in place, it's really awesome because then you have people

that can count on your process.

Because they can count on your process, they know they can't push you around, but they

know their friends can't either.

That makes you a reliable commodity, that they can turn around and sell to their friends

and their neighbors, and say, "Hey, you need to hire Angela's company because she does

have ground rules, because she is consistent, because she is fair, because she does make

you feel like a million bucks, because they do provide excellent service, and because

she's not going to give your time slot away."

It's something that they can count on, and they can turn around and they can sell.

Now, they may not like the fact that there is equality, but the truth of the matter is

you see little kids all the time, they want to push and push and push and push, and you

keep saying, "No, no, no, no, no," and you keep giving them rules and regulations,

but the truth of the matter is they behave better when there is a structure.

They behave better when there are rules, and when they break the rules and there's a consequence,

and the consequence is enforced, they become obedient children because they know where

the boundaries are.

It's the same with customers.

Entitlement, it's up to you, in order to be able to guide your customers in the right direction.

All righty, that's my two cents for today, and until we meet again,

leave the world a cleaner place than when you found it.

For more infomation >> Entitlement - House Cleaning Customers Acting Entitled - Duration: 9:06.

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Babies Make Rainbow Dress for Mommy - Funny Play Doh Stop Motion for Kids - Duration: 10:43.

Hi friends! Thanks for your watching! Don't forget to subscribe!

You can watch more videos in our playlist, its link in the description.

Please leave a like if you enjoyed and tell me what you think in the comments.

Having many interesting video more. Let's follow us!

Thanks for your presence here! Have a nice day!

For more infomation >> Babies Make Rainbow Dress for Mommy - Funny Play Doh Stop Motion for Kids - Duration: 10:43.

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Best Of Cute Golden Retriever Puppies Compilation - Funny Dogs 2018 - Duration: 10:39.

Hi guys! Thanks for your watching! Don't forget to subscribe!

You can watch more videos in our playlist, its link in the description.

Please leave a like if you enjoyed and tell me what you think in the comments.

Having many interesting video more. Let's follow us!

Thanks for your presence here! Have a nice day!

Goodbye! See you again!

For more infomation >> Best Of Cute Golden Retriever Puppies Compilation - Funny Dogs 2018 - Duration: 10:39.

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김주혁 교통사고 사망 김무생 아들 부검 결과 두부손상|K-News - Duration: 4:16.

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Hoe een achter remschijven van remblokken vervangen op een VW GOLF 5 HANDLEIDING | AUTODOC - Duration: 12:03.

Use a wrench № 15 and a spanner № 13

Use a torx №М14

Use a torx №Т30

Treat the brake disc seat with a special copper grease

Treat the brake caliper guide pins with high temperature grease

Using a special tool press in the brake caliper piston