FAQs

FAQ

FREQUENTLY ASKED QUESTIONS

Which are the main parameters of a ventilator?

The main parameters, characteristic to a fan, are four in number: Capacity (V) Pressure (p) Efficiency (n) Speed of rotation (n min.-1)

What is the Capacity?

The capacity is the quantity of fluid moved by the fan, in volume, within a unit of time, and it is usually expressed in m3/h, m3/min., m3/sec.

What is the Total Pressure and how may I calculate it?

The total pressure (pt) is the sum of the static pressure (pst), i.e. the energy required to withstand opposite frictions from the system, and the dynamic pressure (pd) or kinetic energy imparted to the moving fluid (pt = pst + pd). The dynamic pressure depends on both fluid speed (v) and specific gravity (y).

formula-dinamic-pressure

Where:
pd= dynamic pressure (Pa)
y=specific gravity of the fluid(Kg/m3)
v= fluid speed at the fan opening worked by the system (m/sec)

formula-capacity-pressure

Where:
V= capacity(m3/sec)
A= gauge of the opening worked by the system (m2)
v= fluid speed at the fan opening worked by the system(m/sec)

What is output and how may I calculate it?

The efficiency is the ratio between the energy yielded by the fan and the energy input to the fan driving motor

output efficency formula

Where:
n= efficiency (%)
V= capacity (m3/sec)
pt= absorbed power (KW)
P= total pressure (daPa)

What is speed of rotation? What happen changing the number of revolutions?

The speed of rotation is the number of revolutions the fan impeller has to run in order to meet the performance requirements.
As the number of revolutions varies (n), while the fluid specific gravity keeps steady (?), the following variations take place:
The capacity (V) is directly proportional to the speed of rotation, therefore :

t (1)

Where:
n= speed of rotation
V= capacity
V1= new capacity obtained upon varying of the speed of rotation
n1= new speed of rotation

t (2)

Where:
n= speed of rotation
pt= total pressure
pt1= new total pressure obtained upon varying of the speed of rotation
n1= new speed of rotation

The absorbed power (P) varies with cube of rotation ratio, therefore:

formula-speed-rotation-abs.power_

Where:
n= speed of rotation
P= abs. power
P1= new electrical input obtained upon varying of the speed of rotation
n1= new speed of rotation

How the specific gravity may be calculated?

The specific gravity (y) may be calculated with the following formula

gravity formula

Where:
273= absolute zero(°C)
t= fluid temp(°C)
y= air specific gravity at t C(Kg/m3)
Pb= barometric pressure(mm Hg)
13.59= mercury specific gravity at 0 C(kg/dm3)

For ease of calculation, the air weight at various temperatures and heights a.s.l. have been included in the table below:

Temperature

-40°C

-20°C

0°C

10°C

15°C

20°C

30°C

40°C

50°C

60°C

70°C

Height
above
sea level
in meters
0

1,514

1,395

1,293

1,247

1,226

1,204

1,165

1,127

1,092

1,060

1,029

500

1,435

1,321

1,225

1,181

1,161

1,141

1,103

1,068

1,035

1,004

0,975

1000

1,355

1,248

1,156

1,116

1,096

1,078

1,042

1,009

0,977

0,948

0,920

1500

1,275

1,175

1,088

1,050

1,032

1,014

0,981

0,949

0,920

0,892

0,866

2000

1,196

1,101

1,020

0,984

0,967

0,951

0,919

0,890

0,862

0,837

0,812

2500

1,116

1,028

0,952

0,919

0,903

0,887

0,858

0,831

0,805

0,781

0,758

Temperature

80°C

90°C

100°C

120°C

150°C

200°C

250°C

300°C

350°C

400°C

70C

Height
above
sea level
in meters
0

1,000

0,972

0,946

0,898

0,834

0,746

0,675

0,616

0,566

0,524

1,029

500

0,947

0,921

0,896

0,851

0,790

0,707

0,639

0,583

0,537

0,497

0,975

1000

0,894

0,870

0,846

0,803

0,746

0,667

0,604

0,551

0,507

0,469

0,920

1500

0,842

0,819

0,797

0,756

0,702

0,628

0,568

0,519

0,477

0,442

0,866

2000

0,789

0,767

0,747

0,709

0,659

0,589

0,533

0,486

0,447

0,414

0,812

2500

0,737

0,716

0,697

0,662

0,615

0,550

0,497

0,454

0,417

0,386

0,758

Are you a manufacturer or trading company?

Yes, We Zhejiang Lion King Ventilator Co., Ltd. is a professional manufacturer which is the specialist in HVAC fans,axial fans, centrifugal fans, air-conditioning fans, engineering fans etc for the applications of air conditioner, air ex-changer, coolers, heaters, floor convectors, sterilization purifier, air purifiers, medical purifiers, and ventilation ,energy industry, 5G cabinet...

Which level of quality are your products?

We have got AMCA ,CE ,ROHS,CCC certificate so far.
Above average and top class quality are your options in our range. The quality is pretty good ,and trusted by many customers in overseas .

What is your minimum order quantity, can you send me samples?

Our minimum order quantity is 1 set, that means sample order or test order is acceptable, warmly welcome you to come and visit our company.

Can the machine be customized as our need, such as put on our logo?

Surely our machine can be customized as your need, Put on your logo and OEM package are also available.

What's your lead time ? 

7days -25days , depends on volume and different items .

About the after-sale service, how can you solve the problems occurred of your overseas customer in time? 

Always a pre-production sample before mass production;
All products are conducted strict QC and inspection before shipping.
The warranty of our machine is normally 12 months, during this period, we will arrange the international express immediately, to make sure the replace parts to be delivered as soon as possible.

How is your responding time ? 

You will get reply within 2 hours online by Wechat ,Whatsapp , Skype , Messager and Trade manager .
You will get respond within 8 hours offline by email  .
Moble is always availble for picking up your calls .