Harsh Bardhan is an HVAC R & D professional. Skilled in Marketing Communications, IoT, Eurovent, AHRI, AMCA & UL certifications. The best selection of compressor, optimum design of heat exchangers and proper selection of throttling devices with Mollier balancing can make an energy efficient machine.It is my sincere effort to bring to you the best design technology available in the world today !!
Monday, December 17, 2012
Monday, November 26, 2012
HVAC System Design- Formulae
I have been approached by lot of people to teach them system design
for the HVAC&R product development and I thought it fit for them
to start from basics as without solid foundation there can be
no building.So I thought of compiling the basic formulae first and
then go for the system design aspects.It has taken me considerable
time to compile these formulae.
I would like to thank Ms. Ashima Saxena for helping me in editing the list of the compilation.
I would like to thank Ms. Ashima Saxena for helping me in editing the list of the compilation.
Thermodynamic Design Formulae | ||
Sr. No. | EQUATION | FORMULAE |
1 | F = m a | Newton's law of motion |
2 | P = F / A | Pressure |
3 | ρ = m / V | Density |
4 | W = F d | Work |
5 | PE = m g H | Potential energy |
6 | KE = ½ m V2 |
Kinetic energy |
7 | Q = m Cp( t2 - t1 ) |
Sensible heat |
8 | Q = m ( h2 - h1 ) |
Total heat |
9 | W - Q = dE | 1st law of thermodynamics |
10 |
Cpa =
1.005 kJ/kgK
|
Heat capacity of dry air |
11 |
Cpw =
4.193 kJ/kgK
|
Heat capacity of water |
12 |
Cpv =
1.884 kJ/kgK
|
Heat capacity of water vapor |
Heat Transfer Formulae | ||
13 | Q = - k A dt/dx | Conduction |
14 | Q = hc A ( ts - tf ) |
Convection |
15 | Q=σ A Fε FA (t1⁴-t2⁴) | Radiation |
16 | Re = ρ V Dh / µ |
Reynolds number |
17 | Pr = µ Cp / k |
Prandtl number |
18 | Nu = hc D / k |
Nusselt number |
19 | Nu = 0.023 Re0.8 Pr0.4 |
Dittus-Boelter |
Moist Air Phase Formulae | ||
20 | P = Pa + Pv |
Dalton's Law of partial pressure |
21 | Pv = R T | Perfect gas law |
22 | Ra = 0.287 kJ/kgK |
Gas constant of dry air |
23 | Rv = 0.4615 kJ/kgK |
Gas constant of water vapor |
24 | W = 0.622 Pv / (P - Pv) |
Humidity |
25 | Pv =
P / [1+0.622/W] |
Vapor pressure from humidity |
26 | r = (1+W) / v | True density of moist air |
27 | Ps =
0.6105 exp [ 17.27 t / (237.3+t) ] |
Magnus saturation pressure |
28 | t = 237.3 / [17.27 / Ψ -
1] where Ψ = ln (Ps / 0.6105) |
Dew point temperature using the Magnus equation |
29 | f = Pv
/ Ps |
Relative humidity |
30 | Pv = Psw - 1.8( P- Psw )( db - wb )/( 2800 - 1.3 wb ) |
Carrier vapor pressure |
31 | H = 1.005 db + W [ 2500.6 + 1.85 db - 0.023 wb] | Enthalpy |
32 | hfg = 2501.9 - 2.4189 t |
Latent heat of water vapor |
Air Psychometric Formulae | ||
33 | ma =
ρ Qa |
Mass flow of dry air |
34 | Qs = ma Cpm ( t2 - t1 ) |
Sensible duty |
35 | Cpm = 1.023 kJ/kgK |
at typical air-conditioning conditions |
36 | Qt = ma (h2 - h1 ) |
Total duty |
37 | SHR = Qs / Qt |
Sensible heat ratio |
38 | b = ( db0 - adp ) / ( dbi - adp ) |
Bypass factor |
39 | Qs = h A (db - wb) |
Sensible heat at wet wick |
40 | Ql = hd A (Ws,w - W) hfg,w |
Latent heat at wet wick |
41 | hd = hc / Cpm |
Mass transfer coefficient |
Room Heat Formulae | ||
42 | Q = Uo Ao ( to - ti ) |
Heat conduction through a wall |
43 | r = ro
+ Σ t/K + ri |
Wall resistance |
44 | Qsg = SHGF SC
A CLF |
Solar heat gain |
45 | Q = U A CLTD | Cooling load temperature difference method |
Cold Room Formulae | ||
46 | Qpulldown = m C dT |
Pull down load |
47 | Qlatent
= m ∆W λ |
Latent load |
48 | Qrespiration
= m R |
Heat of respiration |
Solar Angle Formulae | ||
49 | d = 23.45 sin ( 360 (284+n) / 365) | Solar Declination |
50 | LST = CT + (Lstd - Lloc)/15 + E + DT |
Local Solar Time |
51 | E = 0.165 sin 2B - 0.126 c os B - 0.025 sin B | Equation of Time |
52 | B = 360 (n- 81) / 364 | Parameter in E |
53 | h = 15 (LST - 12) | Hour angle |
54 | sin β = cos l c osh cos d + sin l sin d | Altitude angle |
55 | cos φ = (cos d sin l cos h - sin d cos l) / cos β | Solar Azimuth |
56 | cos θ = cos β cos λ sin Σ + sin β cos Σ | Angle to surface normal |
Solar Radiation Formulae | ||
57 | IDN =
A e -B / sin β |
Direct Normal Solar Flux |
58 | IdH = C IDN |
Diffuse Horizontal Solar Flux |
59 | ID = IDN cos θ |
Direct Solar Flux on Surface |
Coil Calculation Formulae | ||
60 | dQ = hd dA ( ha - hi ) |
Heat flow on the c oil air side |
61 | dQ = hr
dAi ( ti - tr ) |
Heat flow on the c oil fluid side |
62 | dQs = hc dA ( ta - ti ) |
Air sensible heat |
63 | Q = U A lmtd | Duty from UA LMTD method |
64 | Lmtd = (dti - dto) / Ln( dti / dto ) |
Log mean temperature difference |
65 | Q = e Qmax |
Effectiveness method |
66 | e = (1 - exp(- Ntu (1- Cr)) / (1 - Cr exp(- Ntu (1-Cr)) |
Counter-flow effectiveness |
67 | Cr = Cmin / Cmax |
Capacity ratio |
68 | Ntu = U A / Cmin |
Number of transfer units |
Steam Formulae | ||
69 | λ = 2164 kJ/kgK | Latent heat of vaporization at 2 bar gauge pressure |
70 | λ = 333.6 kJ/kg | Latent heat of freezing |
Fluid Flow in Pipes Formulae | ||
71 | dPfriction = ½ ρ ƒ L V2
/ Dh |
D'Arcy Weisbach friction equation |
72 | 1/√ƒ = -2 Log [ ε / (3.7 Dh) + 2.51 / (Re √ƒ) ] |
Colebrook friction factor |
73 | Dh = 4 A / P |
Hydraulic diameter |
Duct Design Calculation Formulae | ||
74 | P + ½ ρ V2 + ρ g H = constant |
Bernoulli equation |
75 | P1 + ½ ρ V2 + r g H1 = P1 + ½ ρ V2 + ρ g H1 + Ploss |
Modified Bernoulli |
76 | dP = ½ ρ Vd2 [ 0.4 ( 1 - Vd/Vu)2 ] |
Branch straight through dp |
77 | Def = 1.3 (ab)0.625 / (a+b)0.25 |
Effective diameter of rectangular duct |
78 | dP = ½ ρ V2 [ (A1/A2)2 - 1 ] |
dP for ideal flow through a nozzle |
79 | dP = ½ ρ V2 [ 1 - (A1/A2) ]2 |
dP for sudden enlargement |
81 | Re ≈ 67 V Dh |
standard air with V (m/s)
and Dh (mm) |
Fan Laws | |||||
82 | Law 1 | ρ = const | Q ~ ω | SP ~ ω2 |
Pw ~ ω3 |
83 | Law 2 | ω = c onst | Q = const | SP ~ ρ | Pw ~
ρ |
84 | Law 3 | ω ~ 1/√ρ | Q ~ 1/√ρ | SP = const | Pw ~ 1/√ρ |
Sunday, September 23, 2012
Natural Refrigerant - Hydrocarbon
Hydrocarbons are refrigerants that can be used as an alternative to
fluorocarbon
refrigerants in some refrigeration and air conditioning applications.
The term ‘Hydrocarbon’ encompasses following:
A) Ethane (R170)
B) Propane(R290)
C) Butane (R600)
D) Isobutane (R600a)
E) Propylene (R1270)
Properties
1) Hydrocarbons are highly flammable.
2) They have a low toxicity.
3) Hydrocarbon refrigerants are fully compatible with nearly all lubricants commonly used
in refrigeration and air conditioning systems. One major exception to this rule is
lubricants containing silicone and silicate.
Comparison with HCFC
1) HVAC professionals have made a comparative study on the performance of hydrocarbon
refrigerants R290, R600a and R1270 with that of HCFC refrigerant R22 and found that in
comparison to R22, hydrocarbon refrigerants have similar or better ability.
2) An experiment on a new refrigerant blend comprising R134a (an HFC) and hydrocarbon
refrigerants R600a and R290, with a view to finding a replacement for the CFC refrigerant
R12 in domestic refrigerators. The experiment concluded that the blend has been identified
as a promising alternative to be used as a refrigerant in a conventional R12 system and
that the blend reduced energy consumption by 4 to 11%.
3) Hydrocarbon refrigerants generally are compatible with the materials used in systems
designed for R22 and often can use the same or similar lubricants, however, their
substitution requires significant attention to safety issues including application
specific considerations.
4) It has been observed that no (one) refrigerant has been identified as a suitable
alternative for most applications,though they identify that some refrigerant blends “offer
good options”. Blends can be HFC/HFC or HFC/HC.
5) Hydrocarbons may be suitable in some applications, and may not be in others, so every
application needs to be carefully assessed on its merits.
Safety Issues
1) As mentioned above, hydrocarbon refrigerants are flammable and therefore certain
restrictions are placed on their use to ensure safety.
2) All electrical contacts must be sealed or non-sparking.
3) The refrigerant charge in a system below ground level must not exceed 1.0 kg.
4) Sealed systems not exceeding 0.25 kg can be sited in any location.
5) Systems with charges exceeding 0.25 kg must not be located anywhere where a sudden loss
of refrigerant will raise the concentration in the room or occupied compartment above the
practical limit (0.008 kg/m³)
6) Piping for systems exceeding 1.5 kg must be restricted to the room containing the
refrigerant.
Corporate Acceptance
1) In Europe, many models of domestic refrigerators are charged with hydrocarbon
refrigerant in the factory. It is estimated that there are at least 100,000,000 household
refrigerators in use around the world containing hydrocarbon refrigerants.
2) Hydrocarbons have also been used in small air conditioning systems and cold drinking
water dispensers.
3) Hydrocarbon refrigerants are also commonly used in large process refrigeration systems
in the oil and gas industries.
refrigerants in some refrigeration and air conditioning applications.
The term ‘Hydrocarbon’ encompasses following:
A) Ethane (R170)
B) Propane(R290)
C) Butane (R600)
D) Isobutane (R600a)
E) Propylene (R1270)
Properties
1) Hydrocarbons are highly flammable.
2) They have a low toxicity.
3) Hydrocarbon refrigerants are fully compatible with nearly all lubricants commonly used
in refrigeration and air conditioning systems. One major exception to this rule is
lubricants containing silicone and silicate.
Comparison with HCFC
1) HVAC professionals have made a comparative study on the performance of hydrocarbon
refrigerants R290, R600a and R1270 with that of HCFC refrigerant R22 and found that in
comparison to R22, hydrocarbon refrigerants have similar or better ability.
2) An experiment on a new refrigerant blend comprising R134a (an HFC) and hydrocarbon
refrigerants R600a and R290, with a view to finding a replacement for the CFC refrigerant
R12 in domestic refrigerators. The experiment concluded that the blend has been identified
as a promising alternative to be used as a refrigerant in a conventional R12 system and
that the blend reduced energy consumption by 4 to 11%.
3) Hydrocarbon refrigerants generally are compatible with the materials used in systems
designed for R22 and often can use the same or similar lubricants, however, their
substitution requires significant attention to safety issues including application
specific considerations.
4) It has been observed that no (one) refrigerant has been identified as a suitable
alternative for most applications,though they identify that some refrigerant blends “offer
good options”. Blends can be HFC/HFC or HFC/HC.
5) Hydrocarbons may be suitable in some applications, and may not be in others, so every
application needs to be carefully assessed on its merits.
Safety Issues
1) As mentioned above, hydrocarbon refrigerants are flammable and therefore certain
restrictions are placed on their use to ensure safety.
2) All electrical contacts must be sealed or non-sparking.
3) The refrigerant charge in a system below ground level must not exceed 1.0 kg.
4) Sealed systems not exceeding 0.25 kg can be sited in any location.
5) Systems with charges exceeding 0.25 kg must not be located anywhere where a sudden loss
of refrigerant will raise the concentration in the room or occupied compartment above the
practical limit (0.008 kg/m³)
6) Piping for systems exceeding 1.5 kg must be restricted to the room containing the
refrigerant.
Hospitals,
prisons, theaters, supermarkets, schools, hotels, restaurants, dwellings |
• Refrigerant charge must
not
exceed 1.5 kg per sealed
system
• Refrigerant charge must
not
exceed 5.0 kg in special
machinery rooms for indirect systems
|
Offices,
small shops,
small restaurants,
places for generalmanufacturing and where people work |
• Refrigerant charge must
not
exceed 2.5 kg per sealed
system
• Refrigerant charge must
not exceed 10.0 kg in special machinery rooms for indirect
systems
|
Industrial,
cold stores, dairies, abattoirs, non public areas of supermarkets |
• Refrigerant charge must not
exceed 10.0 kg in humanly occupied spaces • Refrigerant charge must not exceed 25.0 kg for systems with high pressure side in special machinery rooms • No restrictions are placed on the charge size if all parts of the system containing refrigerant are in a special machinery room or in open air |
Corporate Acceptance
1) In Europe, many models of domestic refrigerators are charged with hydrocarbon
refrigerant in the factory. It is estimated that there are at least 100,000,000 household
refrigerators in use around the world containing hydrocarbon refrigerants.
2) Hydrocarbons have also been used in small air conditioning systems and cold drinking
water dispensers.
3) Hydrocarbon refrigerants are also commonly used in large process refrigeration systems
in the oil and gas industries.
Natural Refrigerant - Carbon dioxide
The use of Carbon dioxide (R744) as a refrigerant declined for a number of
reasons, including
changes in technology and the introduction of fluorocarbon refrigerants, which were seen
as ‘safety refrigerants’.
Properties
A) Carbon dioxide has an ozone depletion potential (OPD) of zero and a global warming
potential (GWP) of 1.
B) It is generally regarded as a cheap and easily available refrigerant, and many regard
it as an ideal refrigerant.
C) Carbon dioxide is non-toxic. It has low toxicity and is non-flammable.
D) Carbon dioxide is colorless, odorless and is also heavier than air.If enough carbon
dioxide builds up in an enclosed space it will begin to displace oxygen and can cause
asphyxiation in anyone present within the space. As carbon dioxide is colorless and
odorless, a person in the space will not be able to tell unless proper detectors and
alarms are installed.
E) As a refrigerant, carbon dioxide operates at a higher pressure than fluorocarbons and
other refrigerants. While this presents design challenges it can usually be overcome in
systems designed specifically in suction and discharge tubing.
F) Carbon dioxide is not compatible with commonly used refrigeration system lubricants.It
is not suited for use with polyol ester (POE) and poly vinyl ether (PVE) lubricants, and
it has only limited applications with poly alkylene glycol (PAG) lubricants.
Safety Issues
A) Some restrictions are placed on the size of the refrigerant charge, with additional
allowances made for systems with detectors and alarms fitted, and as carbon dioxide is
heavier than air the standard requires “suitable precautions” to be taken to prevent the
undue accumulation of refrigerant in occupied spaces in the event of a leak.
B) As with fluorocarbon refrigerants, the standard also requires the system to be designed
to withstand the refrigerant’s maximum operating pressure.
C) The International Institute of Refrigeration (IIR) identified carbon dioxide’s high
working pressure as the main drawback to its use.
Thermodynamic Properties
1) Carbon dioxide is colorless. At low concentrations, the gas is odorless. At higher
concentrations it has a sharp, acidic odor.
2) At standard temperature and pressure, the density of carbon dioxide is around 1.98
kg/m3, about 1.5 times that of air.
3) Carbon dioxide has no liquid state at pressures below 5.1 standard atmospheres (520
kPa). At 1 atmosphere the gas deposits directly to a solid at temperatures below −78.5 °C
and the solid sublimes directly to a gas above −78.5 °C. In its solid state, carbon
dioxide is commonly called dry ice.
4) Liquid carbon dioxide forms only at pressures above 5.1 atm; the triple point of carbon
dioxide is about 518 kPa at −56.6 °C.The critical point is 7.38 MPa at 31.1 °C.
Corporate Acceptance
Coca Cola company stated that the company’s preliminary field tests proved the technology
to be reliable, in real life circumstances the equipment often used less energy than
equivalent equipment using HFC as a refrigerant.
Till 2006, the company was market testing a range of drinks fridges and vending machines
using carbon dioxide refrigerants.
changes in technology and the introduction of fluorocarbon refrigerants, which were seen
as ‘safety refrigerants’.
Properties
A) Carbon dioxide has an ozone depletion potential (OPD) of zero and a global warming
potential (GWP) of 1.
B) It is generally regarded as a cheap and easily available refrigerant, and many regard
it as an ideal refrigerant.
C) Carbon dioxide is non-toxic. It has low toxicity and is non-flammable.
D) Carbon dioxide is colorless, odorless and is also heavier than air.If enough carbon
dioxide builds up in an enclosed space it will begin to displace oxygen and can cause
asphyxiation in anyone present within the space. As carbon dioxide is colorless and
odorless, a person in the space will not be able to tell unless proper detectors and
alarms are installed.
E) As a refrigerant, carbon dioxide operates at a higher pressure than fluorocarbons and
other refrigerants. While this presents design challenges it can usually be overcome in
systems designed specifically in suction and discharge tubing.
F) Carbon dioxide is not compatible with commonly used refrigeration system lubricants.It
is not suited for use with polyol ester (POE) and poly vinyl ether (PVE) lubricants, and
it has only limited applications with poly alkylene glycol (PAG) lubricants.
Safety Issues
A) Some restrictions are placed on the size of the refrigerant charge, with additional
allowances made for systems with detectors and alarms fitted, and as carbon dioxide is
heavier than air the standard requires “suitable precautions” to be taken to prevent the
undue accumulation of refrigerant in occupied spaces in the event of a leak.
B) As with fluorocarbon refrigerants, the standard also requires the system to be designed
to withstand the refrigerant’s maximum operating pressure.
C) The International Institute of Refrigeration (IIR) identified carbon dioxide’s high
working pressure as the main drawback to its use.
Thermodynamic Properties
1) Carbon dioxide is colorless. At low concentrations, the gas is odorless. At higher
concentrations it has a sharp, acidic odor.
2) At standard temperature and pressure, the density of carbon dioxide is around 1.98
kg/m3, about 1.5 times that of air.
3) Carbon dioxide has no liquid state at pressures below 5.1 standard atmospheres (520
kPa). At 1 atmosphere the gas deposits directly to a solid at temperatures below −78.5 °C
and the solid sublimes directly to a gas above −78.5 °C. In its solid state, carbon
dioxide is commonly called dry ice.
4) Liquid carbon dioxide forms only at pressures above 5.1 atm; the triple point of carbon
dioxide is about 518 kPa at −56.6 °C.The critical point is 7.38 MPa at 31.1 °C.
Corporate Acceptance
Coca Cola company stated that the company’s preliminary field tests proved the technology
to be reliable, in real life circumstances the equipment often used less energy than
equivalent equipment using HFC as a refrigerant.
Till 2006, the company was market testing a range of drinks fridges and vending machines
using carbon dioxide refrigerants.
Natural Refrigerant - Ammonia
Most of the refrigeration and air conditioning equipments in the
world today uses
fluorocarbon refrigerants to facilitate the heat transfer process. Fluorocarbon
refrigerants are synthetic chemicals which causes a high global warming potential,
and are a greater threat to the ozone layer as well if released to the atmosphere.
There are alternatives to these HFC's that can help to mitigate some of the
environmental risks.These are called ‘natural’ refrigerants because
the substances also occur in nature, these alternatives are:
1) Ammonia,
2) Carbon Di Oxide
3) Hydrocarbons
Ammonia (R717)
Ammonia is a naturally-occurring substance that can
be used as a substitute to fluorocarbon refrigerants in
refrigeration systems.
Properties
A) Ammonia (NH3)- R717 is a colorless gas with high pungent smell at atmospheric
pressure, and possesses the ideal environmental properties for a refrigerant – it has
both a zero ozone depletion potential (ODP) and a zero global warming potential (GWP).
B) These properties make ammonia an attractive prospect as a refrigerant, given that
fluorocarbon (HFC) refrigerants can have global warming potentials as high as 3900.
C) Many people are familiar with ammonia as an ingredient in fertilizers and other products.
Ammonia carries a B2 safety classification, meaning that it has a high toxicity, and also
carries a medium flammability risk.
D) Ammonia is not compatible with commonly used refrigeration system lubricants.
It is not suited for use with polyol ester (POE) and poly vinyl ether (PVE) lubricants,
and it has only limited applications with poly alkylene glycol (PAG) lubricants.
Safety Issues
A) A glass of drinking water can contain as much as 1mg of ammonia, a 200gms steak
as much as 13mg, and some food additives can contain as much as 18mg.Cigarette
smoke and even the air we breathe also contains ammonia in small amounts.
B) This demonstrates that the human body can deal with ammonia in small quantities.
Generally, any amount in the atmosphere below 20 parts per million (ppm) is regarded
as not dangerous. At amounts of up to 53 ppm, ammonia’s characteristic odor will be
noticeable.
C) In amounts of 300-400ppm, prolonged exposure will become unpleasant, and in amounts
over 700ppm it can cause burns and serious damage to eyes. In amounts of 5000ppm or
above,exposure can be lethal to humans within five minutes.
Thermodynamic Properties
A) Vapor mass is lighter than air ( 0.6 compared to air 1.0).
B) Ignition will occur at 651 C when vapor concentration is between 15% and 28%.
C) Ammonia corrodes galvanized metals, cast iron, copper, brass & copper alloys.
D) It weighs 5.15 pounds(2.34Kgs) per gallon(3.78 Liter) in liquid conditions
(water weight 8.33 pounds per gallon).
E) Boiling point of liquid ammonia at atmospheric pressure is -2.22 C.
F) Liquid ammonia expands 850 times its liquid volume at atmospheric pressure.
fluorocarbon refrigerants to facilitate the heat transfer process. Fluorocarbon
refrigerants are synthetic chemicals which causes a high global warming potential,
and are a greater threat to the ozone layer as well if released to the atmosphere.
There are alternatives to these HFC's that can help to mitigate some of the
environmental risks.These are called ‘natural’ refrigerants because
the substances also occur in nature, these alternatives are:
1) Ammonia,
2) Carbon Di Oxide
3) Hydrocarbons
Ammonia (R717)
Ammonia is a naturally-occurring substance that can
be used as a substitute to fluorocarbon refrigerants in
refrigeration systems.
Properties
A) Ammonia (NH3)- R717 is a colorless gas with high pungent smell at atmospheric
pressure, and possesses the ideal environmental properties for a refrigerant – it has
both a zero ozone depletion potential (ODP) and a zero global warming potential (GWP).
B) These properties make ammonia an attractive prospect as a refrigerant, given that
fluorocarbon (HFC) refrigerants can have global warming potentials as high as 3900.
C) Many people are familiar with ammonia as an ingredient in fertilizers and other products.
Ammonia carries a B2 safety classification, meaning that it has a high toxicity, and also
carries a medium flammability risk.
D) Ammonia is not compatible with commonly used refrigeration system lubricants.
It is not suited for use with polyol ester (POE) and poly vinyl ether (PVE) lubricants,
and it has only limited applications with poly alkylene glycol (PAG) lubricants.
Safety Issues
A) A glass of drinking water can contain as much as 1mg of ammonia, a 200gms steak
as much as 13mg, and some food additives can contain as much as 18mg.Cigarette
smoke and even the air we breathe also contains ammonia in small amounts.
B) This demonstrates that the human body can deal with ammonia in small quantities.
Generally, any amount in the atmosphere below 20 parts per million (ppm) is regarded
as not dangerous. At amounts of up to 53 ppm, ammonia’s characteristic odor will be
noticeable.
C) In amounts of 300-400ppm, prolonged exposure will become unpleasant, and in amounts
over 700ppm it can cause burns and serious damage to eyes. In amounts of 5000ppm or
above,exposure can be lethal to humans within five minutes.
Thermodynamic Properties
A) Vapor mass is lighter than air ( 0.6 compared to air 1.0).
B) Ignition will occur at 651 C when vapor concentration is between 15% and 28%.
C) Ammonia corrodes galvanized metals, cast iron, copper, brass & copper alloys.
D) It weighs 5.15 pounds(2.34Kgs) per gallon(3.78 Liter) in liquid conditions
(water weight 8.33 pounds per gallon).
E) Boiling point of liquid ammonia at atmospheric pressure is -2.22 C.
F) Liquid ammonia expands 850 times its liquid volume at atmospheric pressure.
Saturday, September 22, 2012
Room Air Conditioner - EPS/Thermocol
EPS often called as Thermocol is designed keeping in mind the
excellent thermal insulation and low cost.When assembled inside the window air conditioner it gives an
excellent mechanical fastening to the partition plate and evaporator.Usually the density of the designed components
is kept at 30 kg/cu.m and the granular size is 5 mm.
Thursday, August 9, 2012
Energy Efficient - Air Conditioners
HVAC is in great demand in America & Europe it is one of the fastest growing consumer durable segment in India...!! The below pics were taken when we were having share holders meet in Lloyd and I was assigned the task of making Product Display Area for R&D.
Floor & Cassette Air Conditioner |
H VAC-My Passion |
R&D Display |
Wednesday, August 8, 2012
Water Cooler
When I joined SRIPL one of the main tasks assigned to me was to Design & Develop energy efficient Water Coolers. I can proudly say that I gave birth to the Water Cooler Division of Shanti Refrigeration Industries Pvt. Ltd.
40/80 Ltrs. Design |
Eureka Forbes Team |
60/80 Ltrs. Design |
Assembly Line View |
Assembly View 150/150 Ltrs. |
60/80 Ltrs. Assembly Line |
Package Air Conditioner
Some of the machines that I designed for
Commercial Air Conditioning
segments' photos are below.
One of the striking features of this machine is that it has got a double
circuit built into one with a twin compressor.
I was really surprised by the results that I obtained. When I measured the
Air Out-let temperature the thermocouple was showing it to be 10.5 C.At that
point of time, I knew my design was perfect.
Off-course the blower selection was tricky. I selected the blower from
Yilida-A Chinese make, I ordered the compressor from Copeland from France.
Coil Protection With EPS Sheet |
I would like to thank my team members-Mr. Arun Tiwari,Mr. Allam Fatih,Mr.
Tension (nick name)
for making this project a success.Needless to say Mr. Fabin Michael &
Mr. Marpu were instrumental in the manufacturing of the coil.
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