Mitsubishi Lossnay LGH TECHNICAL MANUAL

TECHNICAL MANUAL

CONTENTS

CHAPTER 1 Ventilation for Healthy Living

1. Necessity of Ventilation ...................................................................................................................................... 2

2. Ventilation Standards .......................................................................................................................................... 4

3. Ventilation Method .............................................................................................................................................. 5

4. Ventilation Performance ...................................................................................................................................... 8

5. Outdoor Air (ventilation) Load .............................................................................................................................. 10

CHAPTER 2 Lossnay Construction and Principle

1. Construction and Features of Lossnay .............................................................................................................. 16

2. Construction and Principle of Core ...................................................................................................................... 16

3. Calculation of the Total Heat Recovery Efficiency .............................................................................................. 18

4. What is a Psychrometric Chart? ........................................................................................................................ 19

5. Calculation of Lossnay Heat Recovery .............................................................................................................. 20

CHAPTER 3 General Technical Considerations

1. Lossnay Heat Recovery Effect ............................................................................................................................ 22

2. Example Heat Recovery Calculation .................................................................................................................. 24

3. Calculation of Lossnay Economical Effects ........................................................................................................ 26

4. Psychrometric Chart .......................................................................................................................................... 28

5. The Result of No Bacerial Cross Contamination for the Lossnay Core and Determining

Resistance of the Lossnay Core to Molds .......................................................................................................... 29

6. Flame-proofing Properties of Lossnay Core ...................................................................................................... 31

7. Lossnay Core’s Soundproofing Properties Test .................................................................................................. 33

8. Change in Lossnay Core Over Time .................................................................................................................. 34

9. Comparison of Heat Recovery Techniques ........................................................................................................ 36

CHAPTER 4 Characteristics

1. How to Read the LGH Series Lossnay Characteristic Curves ............................................................................ 40

2. Obtaining the Static Pressure Loss .................................................................................................................... 40

3. How to Obtain Efficiency from Characteristic Curves ........................................................................................ 44

4. Sound .................................................................................................................................................................. 45

5. NC Curves (LGH-RX

3 Series) ............................................................................................................................ 51

6. List of Models ...................................................................................................................................................... 55

CHAPTER 5 System Design Recommendations

1. Lossnay Usage Conditions ................................................................................................................................ 60

2. Noise Value of Lossnay with Built-in Fans .......................................................................................................... 61

3. Attachment of Air Filter ...................................................................................................................................... 61

4. Duct Construction .............................................................................................................................................. 61

5. By-pass Ventilation ............................................................................................................................................ 61

6. Transmission Rate of Various Gases and Related Maximum Workplace Concentration .................................. 62

7. Solubility of Odors and Toxic Gases, etc., in Water and Effect on Lossnay Core .............................................. 63

8. Positioning of the Supply/Exhaust Fans and the Air Transmission Rate

(excluding moisture resistant total heat recovery units) ...................................................................................... 64

9. Combined Operation with other Air Conditioners ................................................................................................ 65

10. Automatic Ventilation Switching .......................................................................................................................... 66

11. Vertical Installation of LGH Series ...................................................................................................................... 67

12. Installation of Supplementary Fan Devices After Lossnay Unit .......................................................................... 68

CHAPTER 6 Examples of Lossnay Applications

1. Large Office Building .......................................................................................................................................... 70

2. Medium Size Office Building .............................................................................................................................. 73

3. Multipurpose Tenant Building .............................................................................................................................. 76

4. Urban Small-Scale Building ................................................................................................................................ 79

5. Hospitals ............................................................................................................................................................ 80

6. Schools .............................................................................................................................................................. 82

7. Hotels (convention halls, wedding halls) ............................................................................................................ 84

8. Public Halls (combination facilities such as day-care centres) ............................................................................ 85

CHAPTER 7 Installation Considerations

1. LGH-Series Lossnay Ceiling Embedded-Type (LGH-RX3 Series) ...................................................................... 88

2. Business Lossnay Suspended Exposed-Type .................................................................................................... 91

3. Building Lossnay Pack-type (LP-200B, 350B · 500B · 750B · 1000B) ................................................................ 92

4. Building Lossnay Unit Vertical-type (LUT-2302 · 2303 · 3002 · 3003) ................................................................ 95

5. Building Lossnay Unit Horizontal-type (LU-80 · 160 · 500) ................................................................................ 97

6. Industrial Moisture Resistant Lossnay (LUP-80 · 160 · 500) .............................................................................. 100

CHAPTER 8 Filtering for Freshness

1. Necessity of Filters .............................................................................................................................................. 104

2. Data Regarding Dust .......................................................................................................................................... 104

3. Calculation Table for Dust Collection Efficiency of Each Lossnay Filter ............................................................ 105

4. Comparison of Dust Collection Efficiency Measurement Methods .................................................................... 107

5. Calculation of Dust Concentration ...................................................................................................................... 109

CHAPTER 9 Service Life and Maintenance

1. Service Life ........................................................................................................................................................ 112

2. Cleaning the Lossnay Core and Pre-filter .......................................................................................................... 112

CHAPTER 10 Ventilation Standards in Each Country

1. Ventilation Standards in Each Country ................................................................................................................ 114

2. U.S. ...................................................................................................................................................................... 125

3. U.K. ...................................................................................................................................................................... 125

CHAPTER 11 Lossnay Q and A

CHAPTER 1

Ventilation for Healthy Living

CHAPTER 1 ● Ventilation for Healthy Living

Fresh outdoor air must be introduced constantly at a set ratio in an air conditioning system. This fresh air is introduced to be mixed with the return air from the room, to adjust the temperature and humidity, supply oxygen, reduce body and other odors, remove tobacco smoke and to increase the cleanness of the air. The standard ventilation (outdoor air intake) volume is determined according to the type of application, estimated number of persons in the room, room area, and relevant regulations. Systems which accurately facilitate these requirements are increasingly being required to be installed in buildings.

1. Necessity of Ventilation

The purpose of ventilation is basically divided into “oxygen supply”, “cleaning of air”, “temperature control” and “humidity control”. Cleaning of the air includes the elimination of “odors”, “gases”, “dust” and “bacteria”. The needs of ventilation are divided into “personal comfort”, “assurance of environment for animals and plants”, and “assurance of environments for machinery and constructed materials”. In Japan legal regulations regarding ventilation are set in the Building Srandard Law Enforcement Ordinance and the “Building Management Law” for securing a sanitary environment in buildings. These are in general agreeance with similar regulations in other countries.

1.1 Room air environment in buildings

In Japan, the Building Management Law, a law concerning the sanitary environment of buildings, designates eleven applications including offices, shops, and schools with a total floor area of 3,000 m

or more, as buildings. According to this law maintenance and management of the ventilation and water supply and discharge according to the Environmental Sanitation Management Standards is obligatory.

The following table gives a specific account of buildings in Tokyo. (Tokyo Food and Environment Guidance Center Report)

Specific Account of Buildings in Tokyo (March, 1993)

Number of buildings %

Offices 2,346 65.4

Shops 344 9.6

Department Stores 73 2.0

Schools 388 10.8

Inns 164 4.6

Theaters 84 2.3

Libraries 30 0.8

Museums 15 0.4

Assembly Halls 95 2.6

Art Museums 7 0.2

Amusement Centers 42 1.2

Total 3,588 100.0

Note: Excludes buildings with an expanded floor space of 3,000 to 5,000 m2in particular areas.

The ratio of results of the air quality measurement public inspection and the standard values that were not met (percentage of unsuitability) for the approximately 500 buildings examined in 1980 is shown in the chart at the right.

There was a large decrease in unsuitable percentages of floating particles, but there was almost no change in temperature and carbon dioxide. Values for temperature, ventilation, and carbon monoxide almost entirely cleared the standard values, and are excluded. The study from 1989 shows the item with the highest percentage of unsuitability as temperature with 37%, followed by carbon dioxide at 15%.

76 77 78 79 80 8171 72 73 74 75

83 84

899091 92 93 94 95 96 97 98 99

70 60 50 40 30 20 10



relative humidity

carbon dioxide

temperature

carbon monoxide

ventilation

floating particles

Percentage of unsuitability (%)

Percentage of unsiutability of air quality by year

(according to the Tokyo Food and Environment Guidance Center)

CHAPTER 1 ● Ventilation for Healthy Living

Effect of carbon monoxide (CO) 10,000 ppm = 1%

Concentration (ppm)

Effect of concentration changes

0.01 - 0.2 Standard atmosphere.

5 Considered to be the long-term tolerable value.

The Building Standard Law of Japan, Law for Maintenance of Sanitation in Buildings. Environmental standard 24-hour average.

Considered to be the short-term tolerable value. Environmental standard 8-hour average.

Tolerable concentration for labor environment. (Japan Industrial Sanitation Association)

100

No effect for 3 hours. Effect noticed after 6 hours. Headache, illness after 9 hours; harmful for long-term but not fatal.

200 Light headache in the forehead in 2 to 3 hours.

400 Headache in the forehead, nausea in 1 to 2 hours; headache in the back of head in 2.5 to 3 hours.

800 Headache, dizziness, nausea, convulsions in 45 minutes. Comatose in 2 hours.

1,600 Headache, dizziness in 20 minutes. Death in 2 hours.

3,200 Headache, dizziness in 5 to 10 minutes. Death in 30 minutes.

6,400 Death in 10 to 15 minutes.

12,800 Death in 1 to 3 minutes.

Several 10,000 ppm

This level may be found in automobile exhaust.

(Several %)

Apprpx. 5 ppm is an annual average value in city areas. This value may exceed 100 ppm near roads, in tunnels and parking areas.

Concentration (%) Standards and effect of concentration changes

Approx. 21 Standard atmosphere.

20.5

Ventilation air volume standard will be a guideline where concentration does not decrease more than 0.5% from normal value. (The Building Standard Law of Japan)

20 - 19

An oxygen deficiency of this amount does not directly endanger life in a normal air pressure, but if there is a combustion device in the area, the generation of CO will increase rapidly due to incomplete combustion.

18 Industrial Safety and Health Act. (Hypoxia prevention regulations.)

16 Normal concentration in exhaled air.

16 - 12 Increase in pulse and breathing resulting in dizziness and headaches.

15 Flame in combustion devices will extinguish.

12 Threat to life in short term.

7 Fatal

In the case of Japan, an Instruction Guideline based on these regulations has been issued, and unified guidance is carried out. Part of the Instruction Guideline regarding ventilation is shown below.

●

The fresh outdoor air intake must be 10 m or higher from ground level, and be distanced appropriately from the exhaust air outlet. (Neighbouring buildings must also be considered.)

●

The fresh outdoor air intake volume must be 25 to 30 m3/h·person in design.

●

An air volume measurement hole must be installed at an effective position to measure the treated air volume of the ventilating device.

●

The position and shape of the supply diffuser and return grille must be selected so the air environment in the room is distributed evenly.

1.2 Effect of air contamination on human bodies

Effect of oxygen (O

2) concentration

CHAPTER 1 ● Ventilation for Healthy Living

Effect of carbon dioxide (CO2)

Note: According to Facility Check List published by Kagekuni-sha.

1.3 Effect of air contamination in buildings

●

Dirtiness of interior New ceilings, walls and ornaments will turn yellow in one to two years. This is caused by dust and the tar in tobacco smoke.

2. Ventilation Standards

The legal standards for ventilation differ according to each country. Please follow the standards set by the country. In the US, Ashrae revised their standards in 1989 becoming more strict. In Japan, regulations are set in the The Building Standard Law of Japan Enforcement Ordinance, the so-called “Building Management Law” for securing a sanitary environment in buildings. According to the Building Standards Law, a minimum of

20 m

/h per person of ventilation air is required.

Concentration (%) Effect of concentration changes

0.03 (0.04) Standard atmosphere.

0.04 - 0.06 City air.

0.07 Tolerable concentration when many people stay for long time.

0.10

General tolerable concentration. The Building Standard Law of Japan, Law for Maintenance of Sanitation in Buildings.

0.15 Tolerable concentration used for ventilation calculations.

0.2 - 0.5 Observed as relatively poor.

0.5 or more Observed as the poorest.

0.5 Long-term safety limits (U.S. Labor Sanitation) ACGIH, regulation of laborer offices.

2 Depth of breathing and inhalation volume increases 30%.

3 Work and physical functions deteriorate, breathing doubles.

4 Normal exhalation concentration.

4 - 5

The respiratory center is stimulated; depth and times of breathing increases. Dangerous if breathed in for a long period. If an O

2 deficiency also occurs, trouble will occur sooner and be more dangerous.

When breathed in for 10 minutes, breathing difficulties, redness in the face and headaches will occur. The trouble will worsen when there is also a deficiency of O

18 or more Fatal

There is no toxic level in CO2 alone. However, these tolerable concentrations are a guideline of the contamination estimated when the physical and chemical properties of the air deteriorate in proportion to the increase of CO2

CHAPTER 1 ● Ventilation for Healthy Living

3. Ventilation Method

3.1 Ventilation class and selection points

An appropriate ventilation method must be selected according to the purpose. Ventilation is composed of “Supply air” and “Exhaust air” functions. These functions are classified according to natural flow or mechanical ventilation using a fan (forced ventilation).

Classification of mechanical ventilation

Classification of ventilation (according to Building Standards Law)

1. Class 1 ventilation

Fresh outdoor air is mechanically brought in and simultaneously the stale air in the room is mechanically discharged.

2. Class 2 ventilation

Fresh outdoor air is mechanically brought in and the exhaust air is discharged from the exhaust air outlet (natural).

3. Class 3 ventilation

The stale air in the room is mechanically discharged and simultaneously fresh outdoor air is mechanically introduced from the supply air diffuser (natural).

Ex. of application

• Ventilation of air conditioned rooms. (buildings, hospitals, etc.)

• Ventilation of room not facing an outer wall. (basement, etc.)

• Ventilation of large room. (office, large conference room, hall, etc.)

• Surgery theatre.

• Clean rooms.

• Foodstuff processing

factories.

• Local ventilation in kitchens.

• Ventilation of hot exhaust air from machine room, etc.

• Ventilation of humid exhaust air from indoor pools, bathrooms, etc.

• General simple ventilation.

System effect

By changing the balance of the supply fan and exhaust fan’s air volumes, the pressure in the room can be balanced freely, and the interrelation with neighboring spaces can be set freely.

As the room is pressurized, the flow of odors and dust, etc., from neighboring areas can be prevented.

The exhaust air is removed from a local position in the room, and dispersion of the stale air can be prevented by applying an entire negative pressure.

Design and construction

properties

•

An ideal design in which the supply air diffuser and exhaust air outlet position relation and air volume, etc., can be set freely is possible.

• A system which adjusts the temperature and humidity of the supply air diffuser flow to the room environment can be incorporated.

•

The supply and exhaust volume can be set freely according to the changes in conditions.

• The position and shape of the supply air diffuser can be set.

• The temperature and humidity of the supply air diffuser flow can be set accordingly, and dust can be removed as required.

• Effective exhausting of dispersed stale air generation sites is possible from a local exhaust air outlet.

• Ventilation in which the air flow is not felt is possible with the supply air diffuser setting method.

Selection points

• Accurate supply air diffuser can be maintained.

• The room pressure balance can be maintained.

• The supply air diffuser temperature and humidity can be adjusted and dust treatment is possible.

• The pressure is positive.

•

The supply air diffuser temperature and humidity can be adjusted, and dust treatment is possible.

•

The positional relation of the exhaust air outlet to the supply air diffuser is important.

• The room pressure is negative.

• Local exhaust is possible.

• Ventilation without dispersing stale air is possible.

• Ventilation with reduced air flow is possible.

•

The positional relation of the exhaust air outlet to the supply air diffuser is important.

Supply air diffuser

Exhaust fan

Exhaust air outlet

Exhaust fan

Stale air

Fresh outdoor air

Supply Exhaust Ventilation volume Room pressure

Class 1 Mechanical Mechanical Random (constant) Random

Class 2 Mechanical Natural Random (constant) Positive pressure

Class 3 Natural Mechanical Random (constant) Negative pressure

Class 4 Natural Mechanical & natural Limited (inconstant) Negative pressure

1) System operation with cassette-type air conditioner

2) System operation with ceiling embedded-type air conditioner

3) Independent operation with ceiling suspended-type air conditioner

CHAPTER 1 ● Ventilation for Healthy Living

3.2 Comparison of ventilation methods

There are two main types of ventilation methods.

Centralized ventilation method

This is mainly used in large buildings, with the fresh outdoor air intake being installed in one machine room. For this method, primary treatment of the fresh outdoor air, such as heat recovery to the intake air and dust removal is performed being distribution to the building by ducts.

Independent zoned ventilation method

This is mainly used in small to medium sized buildings, with areas being ventilated using fresh outdoor air intakes formed of independent ventilation devices. The rate of use of this method has recently increased as independent control is becoming ever more feasible.

Centralised ventilation method Independent zoned ventilation method

Air intake

(fresh out-

door air)

Filters

Air exhaust (stale air)

Cassette-type package air conditioner or fan coil unit

Cassette-type or ceiling suspended-type package air conditioner or fan coil unit

Ceiling-mounted type Lossnay or ceiling embedded-type Lossnay

Exhaust grill

Ceiling recessedtype Lossnay

Exhaust air Fresh outdoor air

Finished ceiling

Fresh outdoor air Exhaust air

Finished ceiling

Lossnay

Supply fan

Exhaust

Each unit

Ceiling embedded-type package air conditioner or fan coil unit

Ceiling recessedtype Lossnay

Exhaust grill

Exhaust air Fresh outdoor air

Finished ceiling

CHAPTER 1 ● Ventilation for Healthy Living

Comparison of centralised ventilation method and independent zoned ventilation method

Centralized ventilation method

The air transfer distance is long thus requiring much fan power.

• Independent equipment room is required.

• Duct space is required.

• Penetration of floors with vertical shaft is not

desired in terms of fire prevention.

Generalized per system.

• Design of outer wall is not lost.

• The indoor supply air diffuser and return grille

can be selected freely for an appropriate design.

As there are many common-use areas, if the building is a tenant building, an accurate assessment of operating cost is difficult.

• As the usage time setting and ventilation volume control, etc., is performed in a central monitoring room, the user’s needs may not be met appropriately.

• A large amount of ventilation is required even for a few persons.

• An ideal supply air diffuser and return grille position can be selected as the supply air diffuser and return grilles can be laid out freely.

• The only noise in the room is the aerodynamic sound.

• Anti-vibration measures must be taken as the fan in the equipment room is large.

• Centralized management is easy as it can be performed in the equipment room.

• The equipment can be inspected at any time.

• Large as the entire system is affected.

• Immediate inspection can be performed in the

equipment room.

Fan power

Installation space

Zoning

Designability

Clarification of costs

Controllability

Comfort

Maintenance and management

Trouble correspondence

Independent zoned ventilation method

As the air transfer distance is short, the fan power is small.

• Independent equipment room is not required.

• Piping space is required only above the ceiling.

Can be utilised for any one area.

• The number of intakes and exhaust air outlets on the outer wall will increase; design must be considered.

• The design will be fixed due to the installation fittings, so the design of the intakes and exhaust air outlets must be considered.

Invoicing for each zone separately is possible, even in a tenant building.

• The user in each zone can operate the ventilator freely.

• The ventilator can be operated even during offpeak hours.

• Consideration must be made of the noise from the main unit.

• Anti-vibration measures are often not required as the unit is compact and the vibration generated can be dispersed.

• Work efficiency is poor as the equipment is not centrally located.

• An individual unit can be inspected only when the room it serves is vacant.

• Limited as only independent units are affected.

• Consultation with the tenant is required prior to

inspection of an individual unit.

CHAPTER 1 ● Ventilation for Healthy Living

4. Ventilation Performance

The ventilation performance is largely affected by the installation conditions. Ample performance may not be achieved unless the model and usage methods are selected according to the conditions. Generally, the ventilation performance is expressed by “Air volume” and “wind pressure (static pressure)”, and these are necessary when considering ventilation.

4.1 Air volume

Air volume expresses the volume of air exhausted (or supplied) by the unit in a given period. Generally, this is expressed as m

/hr (hour).

4.2 Wind pressure

When a piece of paper is placed in front of a fan and let go, the piece of paper will be blown away. The force that blows the paper away is called the wind pressure, and this is normally expressed in units of mmH2O or mmAq {Pa (Pascal) in SI unit system: 1 mmH2O = approx. 9.8Pa}. The wind pressure is divided into the following three types:

4.2.1 Static pressure

This is the force that presses the surroundings when the air is still such as in an automobile tyre or rubber balloon. For example, in a water gun, the hydraulic pressure increases when pressed by a piston, and if there is a small hole, the water sprays out with force. The pressure of this water is equivalent to the static pressure for air. The higher the pressure is, the further the water (air) can be sprayed.

4.2.2 Dynamic pressure

This expresses the speed at which air flows, and can be thought of as the force at which a typhoon presses against a building.

4.2.3 Total pressure

This is the total force that wind has, and is the sum of the static pressure and dynamic pressure.

CHAPTER 1 ● Ventilation for Healthy Living

4.3 Measurement of the air volume and wind pressure

Mitsubishi measures the machine’s air volume and wind pressure with a device as shown below according to the Japan Industrial Standards (JIS B 8628).

Measuring device using orifice (JIS B 8628 standards)

Static pressure (

)

Air volume (Q)

Measurement method

The unit is operated with the throttle device fully closed. There is no air flow at this time, and the air volume is 0. The maximum point of the static pressure (A point, the static pressure at this point is called the totally closed pressure) can be obtained. Next, the throttle device is gradually opened, the auxiliary fan is operated, and the middle points (points B, C and D) are obtained. Finally, the throttle device is completely opened, and the auxiliary fan is operated until the static pressure in the chamber reaches 0. The maximum point of the air volume (point E, the air volume at this point is called the fully opened air volume) is obtained. The points are connected as shown below, and are expressed as air volume, static pressure curves (Q-H curve).

Connection

Wind dispersing place

Connection

Rectifying

grid

Rectifying

grid

Supply

Air

(SA)

Chamber

Return

Air

(RA)

Rectifying net

Rectifying

net

Wind gauge

duct path

Orifice

Wind gauge

duct path

Orifice

Damper

Blower

Test unit

Static pressure in chamber (Static pressure measurement)

Pressure

difference before

and after orifice

(Air volume

measurement)

A) When measuring the supply air volume (with the orifice plate)

B) When measuring the return air volume (with the orifice plate)

CHAPTER 1 ● Ventilation for Healthy Living

5. Outdoor Air (ventilation) Load

5.1 How to calculate each approximate load

The outdoor air load can be calculated with the following formula if the required outside air intake volume Q m3/h to be introduced is known:

(Outdoor air load) = γ · QF · (iO - iR)

= γ [kg/m

] × S[m2] × k × n [person/m2] × Vf [m3/h·person] × (iO

- iR): ∆i [kJ/kg (kcal/kg)]

γ : Specific gravity of air - 1.2 kg/m

S : Building’s airconditioned area k : Thermal coefficient; generally 0.7 - 0.8. n : The average population concentration is the inverse of the occupancy area per person. If the number of persons in the

room is unclear, refer to the Floor space per person table below.

Vf : Outdoor air intake volume per person

Refer to the Required outdoor air intake volume per person table below. iO : Outdoor air enthalpy - kJ/kg (kcal/kg’) iR : Indoor enthalpy - kJ/kg (kcal/kg’)

Floor space per person table (m

)

(According to the Japan Federation of Architects and Building Engineers Associations)

Required outdoor air intake volume per person table (m

/h·person)

Caution

The application of this table to each type of room should be carefully considered in relation to the degree of smoking in the room.

Office building

Department store, shop

Restaurant

Teatre or

Average Crowded Empty

cinema hall

General design 4 - 7 0.5 - 2 0.5 - 2 5 - 8 1 - 2 0.4 - 0.6

value

5 3.0 1.0 6.0 1.5 0.5

Application example

Required ventilation volume

Degree of smoking

Recommended value Minimum value

Broker’s office

Extremely heavy Newspaper editing room 85 51

Conference room

Quite heavy

Bar

51 42.5

Cabaret

Heavy

Office

25.5

Restaurant 20

Light

Shop

25.5 17

Department store

None

Theatre 25.5 17 Hospital room 34 25.5

Cooling load per unit area

When the volume of outdoor air per person is 25 m

/h, and the number of persons per 1 m2is 0.2, the cooling load will be

approximately 157.0 W/m

(135 kcal/h·m2).

How these values are determined can be seen as follows:

● Outdoor air load

Air conditions <Standard design air conditions in Tokyo>

CHAPTER 1 ● Ventilation for Healthy Living

Example calculations of determining ventilation load during both cooling and heating are given as follows:

5.2 Ventilation load during cooling (in general office building)

● Classification of cooling load

(a) is the heat infiltrating the room, and often is 30 to 40% of the entire cooling load. (b) is the heat generated in the room. (c) is applies only when reheating is necessary. (d) is the heat generated when outdoor air is mixed into part of the supply air diffuser volume and introduced into the room. The outdoor air is introduced to provide ventilation for the people in the room, and is referred to as the ventilating load.

Typical load values (during cooling)

Type of load Load

Outdoor air load 53.0 W/m

(45.6 kcal/h·m2)

Indoor

People 26.4 W/m

(22.7 kcal/h·m2)

generated heat

Lighting equipment 30.0 W/m

(25.8 kcal/h·m2)

Indoor infiltration heat 47.6 W/m

(40.9 kcal/h·m2)

Total 157.0 W/m

(135.0 kcal/h·m2)

Conditions: Middle floor of a general office building facing south.

Class

Heat from walls (q

WS)

(a) Indoor infiltration heat Heat from glass

from direct sunlight (qGS) from conduction & convection (q

GS)

Accumulated heat load in walls (q

)

Generated heat from people

Sensible heat (q

HS)

(b) Indoor generated heat

Latent heat (q

HL)

Genarated heat from electrical equipment Sensible heat (q

ES)

Latent heat (q

EL)

RL)

(d) Outdoor air load

Sensible heat (q

FS)

Latent heat (qFL)

}

Dry bulb temp.

Relative humidity

Wet bulb temp. Enthalpy Enthalpy difference

Cooling

Outdoor air 33 °C 63% 27 °C 85 kJ/kg (20.3 kcal/kg’)

31.8 kJ/kg

Indoors 26 °C 50% 18.7 °C 53.2 kJ/kg (12.7 kcal/kg’)

(7.6 kcal/kg’)

When the load per floor area of 1 m2with a ventilation volume of 25 m3/h·person is calculated with the above air conditions, the following is obtained:

Outdoor air (ventilation) load = 1.2 kg/m

(Specific gravity of air) × 0.2 persons/m2(no. of persons per 1 m2)

× 25 m

/h·person (outdoor air volume) × 31.8 kJ/kg (7.6 kcal/kg’) (air enthalpy difference indoors/outdoors)

= 190.8 kJ/h·m

(530 W/m2)

The Lossnay recuperates approximately 70% of the exhaust air load and saves on approximately 20% of the total load.

Outdoor air

load 33.8%

53.0 W/m

(45.6 kcal/h·m2)

Indoor infiltration heat 30.3%

47.6 W/m

(41.8 kcal/h·m2)

Indoor generated heat (people, lighting

equipment) 35.9%

56.4 W/m

156.5 W/m

(135.0 kcal/h·m2)

CHAPTER 1 ● Ventilation for Healthy Living

● Determining internal heat gain

When classifying loads, the internal heat gain (indoor generated heat + indoor infiltration heat) will be the value of the outdoor air load subtracted from the approximate cooling load when it is assumed that there is no reheating load.

(Internal heat gain)

= 157.0 W/m

(135 kcal/h·m2) – 53.0 W/m2(45.6 kcal/h·m2) = 104.0 W/m2(89.4 kcal/h·m2)

●

This value of internal heat gain is based on assumptions for typical loads. To determine individual levels of internal heat gain, the following is suggested:

● Indoor generated heat

(1) Heat generated from people

Heat generation design value per person in office

Sensible heat (SH)= 63.0 W·person (54 kcal/h·person) Latent heat (LH) = 69.0 W·person (59 kcal/h·person) Total heat (TH) = 132.0 W·person (113 kcal/h·person)

The heat generated per 1 m

of floor space is

(heat generated from people)

= 132.0 W·person (113 kcal/h·person) × 0.2 person/m

= 26.4 W/m2(22.6 kcal/h·m2)

(2) Heat generated from electrical equipment (lighting)

The approximate value of the room illuminance and power for lighting for a general office with illuminance of 300 350 Lux, is 20 - 30 W/m

● Indoor infiltration heat

This is the heat that infiltrates into the building from outside. This can be determined by subtracting the amount of heat generated by people and lighting from the internal heat gain. (Indoor infiltration heat)

= 104.0 – (26.4 + 30.0) = 47.6 W/m

(40.9 kcal/h·m2)

The Lossnay recuperates approximately 70% of the outdoor air load and saves on approximately 20% of the total load.

CHAPTER 1 ● Ventilation for Healthy Living

5.3 Ventilation load during heating

●

Classification of heating load

Class

Heat lost from walls (q

WS)

(a)

Indoor heat

Heat lost from glass (q

GS)

loss

Heat loss from conduction & convection (q

GS)

Accumulated heat load in walls (q

SS)

(b)

Outdoor air

Sensible heat (q

FS)

load

Latent heat (q

FL)

During heating, the heat generated by people and electrical equipment in the room can be subtracted from the heating load. However, as the warming up time at the start of heating is short, this generated heat may be ignored in some cases.

Percentage of load

Internal heat loss

In terms of load classification, the internal heat loss is the value of the outdoor air load subtracted from the approximate heating load.

Internal heat loss = 133.7 W/m

(115.0 kcal/h·m2) – 56.0 W/m2(48.2 kcal/h·m2) = 77.7 W/m2(66.8 kcal/h·m2)

Heating load per unit area

When the outdoor air volume per person is 25 m

/h, and the number of persons per 1 m2is 0.2 persons, the approximate

heating load will be approximately 133.7 W/m

(115 kcal/h·m2).

●

Outdoor air load

Air conditions <Standard design air conditions in Tokyo>

Type of load Load

Outdoor air load 56.0 W/m

(48.2 kcal/h·m2)

Internal heat 77.7 W/m

(66.8 kcal/h·m2)

Total 133.7 W/m

(115.0 kcal/h·m2)

Conditions: Middle floor of a general office building facing south.

Dry bulb temp.

Relative humidity

Wet bulb temp. Enthalpy Enthalpy difference

Heating

Outdoor air 0 °C 50% –3 °C 5.0 kJ/kg (1.2 kcal/kg’)

33.5 kJ/kg

Indoors 20 °C 50% 13.7 °C 38.5 kJ/kg (9.2 kcal/kg’)

(8.0 kcal/kg’)

When the load per 1 m2of floor area with a ventilation volume of 25 m3/h·person is calculated with the above air conditions, the following is obtained:

Outdoor air (ventilation) load = 1.2 kg/m

× 0.2 persons/m2× 25 m3/h·person × 33.5 kJ/kg (8.0 kcal/kg’)

= 201.0 kJ/h·m

(56 W/m2)

The Lossnay recuperates approximately 70% of the outdoor air load and saves on approximately 30% of the total load.

Outdoor

air load 41.9%

56.0 W/m

(48.0 kcal/h·m2)

Indoor heat loss 58.1%

77.7 W/m

(67.0 kcal/h·m2)

133.7 W/m

(115.0 kcal/h·m2)

CHAPTER 2

Lossnay Construction and Principle

CHAPTER 2 ● Lossnay Construction and Principle

1. Construction and Features of Lossnay

● Lossnay construction

The Lossnay is constructed so that the exhaust air passage from the indoor side to the outdoor side (RA → EA) and the fresh air passage from the outdoor side to the indoor side (OA → SA) cross. The Lossnay heat recovery unit (Lossnay Core) is installed at this cross point, and recovers the heat by conduction through the separating medium between these airflows. This enables the heat loss during exhaust to be greatly reduced.

* RA : Return Air

EA : Exhaust Air OA : Outdoor Air SA : Supply Air

SA (Supply air diffuser)

Supply fan

RA (Return air)

Exhaust side filter

Lossnay Core

Intake side filter

OA (Outdoor air)

Exhaust fan

EA (Exhaust air)

Main Features of Lossnay

(1) Cooling and heating maintenance fees are saved while ventilating.

(2) The capacity and performance of the air conditioner can be reduced.

(3) Dehumidifying during summer, and humidifying during winter is possible.

(4) Comfortable ventilation is possible, (the outdoor air being adjusted to the room temperature.)

(5) Effective sound-proofing.

Note: The dust inlet and outlet are linear in the

actual product.

2. Construction and Principle of Core

● Simple construction

The Lossnay Core is a cross-flow total heat recovery unit constructed of plates and fins made of treated paper. The fresh air and exhaust air passages are totally separated allowing the fresh air to be introduced without mixing with the exhaust air.

●

Principle

The Lossnay Core uses the heat transfer properties and moisture permeability of the treated paper. Total heat (sensible heat plus latent heat) is transferred from the stale exhaust air to the fresh air being introduced into the system when they pass through the Lossnay. Try this simple experiment. Roll a piece of paper into a tube and blow through it. Your hand holding the paper will immediately feel warm. If cold air is blown through the tube, your hand will immediately feel cool. Lossnay is a total heat exchanger that utilizes these special properties of paper.

●

Treated paper

The paper partition plates are treated with special chemicals so that the Lossnay Core is an appropriate heat recovery unit for the ventilator. This paper differs from ordinary paper, and has the following unique properties.

(1) The paper is incombustible and is strong.

(2) The paper has selective hydroscopicity and moisture permeability that permits the passage of water vapor only (including

some water-soluble gases).

(3) The paper has gas barrier properties that does not pass gases such as CO

SA Supply air diffuser (Fresh cold or warm air)

Partition plate (Treated paper)

Spacer plate (Treated paper)

RA Return air (Stale cold or warm air)

Indoors Outdoors

EA Exhaust air (Stale air)

OA Outdoor air (Fresh air)

CHAPTER 2 ● Lossnay Construction and Principle

A comparison of the ordinary paper and the Lossnay Core plates is as shown in the table.

Ordinary paper

Water vapor is transferred, but gas elements that are easily dissolved in water such as CO

2, NO2 are also transferred.

The contaminated air passes through the plates during ventilation and returns to the room.

Treated paper

Water vapor is transferred, but gas elements such as CO

2 are not transferred.

The contaminated air does not return to the room when ventilated.

Highly humid air

Water vapor

CO2 NO2

CO2 NO2Water vapor

Water vapor

Treatment (Selective permeable film) (Incombustible specifications)

Low humid air

Highly humid air

Cellulose fibers

Low humid air

● Total heat recovery mechanism

Sensible heat and latent heat

The heat that enters and leaves in accordance with changing temperature (rise or drop) is called sensible heat. The heat that enters and leaves due to the changes in a matter’s physical properties (evaporation, condensation) is called latent heat.

(1) Temperature (sensible heat) recovery

1) Heat conduction and heat passage is performed through a partition plate from the high temperature to low temperature side.

2) As shown on the right, the heat recovery efficiency is affected by the resistance of the boundary layer, and for the Lossnay there is little difference when compared to materials such as copper or aluminium which also have high thermal conductivity.

Heat resistance coefficients

Ra1

Ra2

Partition plate Ra1+Ra2

»Rp

Treated paper Cu Al

1 10 10 10

Rp 1 0.00036 0.0006

2 10 10 10

Total 21 20.00036 20.0006

(2) Humidity (latent heat) recovery

●

Water vapor is moved through the partition plate from the high humidity to low humidity side by means of the differential pressure in the vapor.

High humidity side

Low humidity side

Partition plate

CHAPTER 2 ● Lossnay Construction and Principle

3. Calculation of the Total Heat Recovery Efficiency

The Lossnay Core’s heat recovery efficiency can be considered using the following three transfer rates:

(1) Temperature (sensible heat) recovery efficiency

(2) Humidity (latent heat) recovery efficiency

(3) Enthalpy (total heat) recovery efficiency

The heat recovery effect can be calculated if two of the above efficiencies is known. (The temperature and enthalpy efficiencies are indicated in the applicable catalogue.)

●

Each recovery efficiency can be calculated with the formulas given below.

●

When the supply air volume and exhaust air volume are equal, the heat recovery efficiencies on the supply and exhaust sides are the same.

●

When the supply air volume and exhaust air volume are not equal, the total heat recovery efficiency is low if the exhaust volume is lower, and high if the exhaust volume is higher. Refer to the Heat Recovery Efficiency Correction Curve in the applicable catalogue for more details.

SA Supply air (Fresh cold or warm air)

RA Return air (Stale cold or warm air)

Indoors Outdoors

EA Exhaust air (Stale air)

OA Outdoor air (Fresh air)

Item Formula

Temperature recovery efficiency (%)

ηt =

t (

OA) - t (SA)

× 100

t (

OA) - t (RA)

Enthalpy recovery efficiency (%)

ηi =

i (

OA) - i (SA

)

× 100

i (

OA) - i (

RA)

η: Efficiency (%)

t : Dry bulb temperature (°C)

i : Enthalpy (kJ/kg) (kcal/kg’)

Calculation of air conditions after passing through Lossnay

If the Lossnay heat recovery efficiency and the conditions of the room and outdoor air are known, the conditions of the air entering the room and the air exhausted outdoors can be determined with the following formulas.

Supply side Exhaust side

Temperature t

SA = tOA - (tOA - tRA) · ηttEA = tRA + (tOA - tRA) · ηt

Enthalpy i

SA = iOA - (iOA - iRA) · ηiiEA = iRA + (iOA - iRA) · ηi

CHAPTER 2 ● Lossnay Construction and Principle

4. What is a Psychrometric Chart?

The chart which shows the properties of humid air is called a psychrometric chart. The psychrometric chart can be used to find the (1) Dry bulb temperature, (2) Wet bulb temperature, (3) Absolute humidity, (4) Relative humidity, (5) Dew point and (6) Enthalpy (total heat) of a certain air condition. If two of these values are known beforehand, the other values can be found with this chart. The way that the air will change when it is heated, cooled, humidified or dehumidified can also be seen easily on the chart.

(1) Dry bulb temperature t (°C)

Generally referred to as standard temperature this is measured with a dry bulb thermometer (conventional thermometer). The obtained value is the dry bulb temperature.

(2) Wet bulb temperature t’ (°C)

When a dry bulb thermometer’s heat sensing section is wrapped in a piece of wet gauze and an ample air flow (3 m/s or more) is applied, the heat applied to the wet bulb by the air and the heat of the water vapor that evaporates from the wet bulb will balance at an equal state. The temperature indicated at this time is called the wet bulb temperature.

(3) Absolute humidity x (kg/kg’)

The weight (kg) of the water vapor that corresponds to the weight (kg’) of the dry air in the humid air is called the absolute humidity.

(4) Relative humidity ϕ (%)

The ratio of the water vapor pressure Pw in the humid air and the water vapor pressure Pws in the saturated air at the same temperature is called the relative humidity. This is obtained with the following formula:

ϕR = PW/PWS × 100

(5) Dew point t” (°C)

The water content in the air will start to condense when air is cooled. The dry bulb temperature at this time is called the dew point.

(6) Enthalpy i (kJ/kg) (kcal/kg’)

Physical matter has a set heat when it is at a certain temperature and state. This retained heat is called the enthalpy, with dry air at 0 °C being set at 0.

Temperature (°C)

Absolute humidity x (kg/kg’)

Wet bulb temperature

(dew point) t’ (°C)

Relative humidity ϕ (%)

The dew point t” of the air at point A is the temperature of the point at the same absolute humidity as point A on the saturation curve.

t” °C dew point

(kJ/kg)

Enthalpy i (kcal/kg’)

t”

Parallel to absolute temperature scale line

CHAPTER 2 ● Lossnay Construction and Principle

5. Calculation of Lossnay Heat Recovery

The following figure shows the conditions of various air states when fresh air is introduced through the Lossnay Core. If a conventional sensible heat recovery unit is used alone and is assumed to have the same heat recovery efficiency as Lossnay, the condition of the air supplied to the room is expressed by point A in the figure. This point shows that the air is very humid in summer and very dry in winter. The air supplied to the room with Lossnay is indicated by point S in the figure. The air is precooled and dehumidified in the summer and preheated and humidified in the winter before it is introduced to the room.

iSA

iOA

tOA tSA

iSA

iOA

tRA tRA

SA tOA

XOA

XSA

XRA

XSA

XOA

iRA

The quantity of heat recovered by using the Lossnay Core can be calculated with the following formula.

Total heat recovered: q

T = γ · Q · (iOA - iSA) [W (kcal/h)]

= γ · Q · (i

- i

RA) ×ηi

Where γ = Specific weight of air under standard conditions 1.2 (kg/m

)

Q = Treated air volume (m

/h) t = Temperature (°C) x = Absolute humidity (kg/kg’) i = Enthalpy (kJ/kg) (kcal/kg’) η = Heat recovery efficiency (%)

●

Suffix meanings

OA : Outdoor air RA : Return air SA : Supply air

Enthalpy

(kJ/kg) (kcal/kg

’)

Outdoor air load

Lossnay Core heat recovery

Enthalpy

(kJ/kg) (kcal/kg

’)

Outdoor air load

Lossnay Core heat recovery

Outdoor air

condition in

winter

Supply air condition of

the Lossnay

Supply air condition of

the Lossnay

Room air

condition

in summer

Outdoor air condition

in summer

Absolute

humidity (kg/kg’)

Room air condition in winter

Dry bulb temperature (°C)

CHAPTER 3

General Technical Considerations

1. Lossnay Heat Recovery Effect

1.1 Comparison of outdoor air load of various ventilators

Examples of formulas to compare the heat recovered and outdoor air load when ventilating with the Lossnay (total heat recovery unit), sensible heat recovery ventilation (sensible HRV) and conventional ventilators are shown below.

(1) Cooling during summer

Conditions

●

Model LGH-50R type

●

Heat recovery efficiency table (%)

(at 50Hz, high speed) (For summer)

●

Ventilation rate: 500 m3/h (specific gravity of air

= 1.2 kg/m3)

CHAPTER 3 ● General Technical Considerations

Lossnay Sensible HRV

Conventional

ventilator

Temperature

77 77 –

(sensible heat)

Enthalpy

61.5 18.2* –

(total heat)

hOA

hSA

hRA

85.0

65.4

53.2

tOA

tSA

27.6

tRA

0.0203

XSA

0.0148

XRA

0.0105

●

Lossnay (Supply air diffuser temperature)

tSA = 33°C – (33°C – 26°C) × 0.77 = 27.6°C

(Supply air diffuser enthalpy)

hSA = 85.0 – (85.0 – 53.2) × 0.615 = 65.4 kJ/kg

Heat recovered

(85.0 – 65.4) × 1.2 × 500 = 11,760 kJ/h = 3.3 kW (2,809 kcal/h)

Outdoor air load

(65.4 – 53.2) × 1.2 × 500 = 7,320 kJ/h = 2.0 kW (1,749 kcal/h)

●

Sensible HRV (Supply air diffuser temperature)

tSA = 33°C – (33°C – 26°C) × 0.77 = 27.6°C

(Supply air diffuser enthalpy)

hSA

= 79.2 kJ/kg (18.9 kcal/kg) (from psychrometric chart)

Heat recovered

(85.0 – 79.2) × 1.2 × 500 = 3,480 kJ/kg = 1.0kW (831 kcal/h)

Outdoor air load

(79.2 – 53.2) × 1.2 × 500 = 15,600 kJ/H = 4.3 kW (3,727 kcal/h)

[Calculated enthulpy recovery efficiency 3,480 ÷ (3,480 + 15,600) × 100 = 18.2]

●

Conventional ventilator If a conventional ventilator is used, the heat recovered will be 0 as the supply air diffuser is equal to the outdoor air. The outdoor air load is: (85.0 – 53.2)

1.2 ×500 = 19,080 kJ/h = 5.3 kW (4558 kcal/h)

Calculation example Summer conditions

Absolute humidity (kg/kg’)

Room air condition in summer

Outdoor air condition

in summer

Supply air condition

of the Lossnay

Dry bulb temperature (°C)

y h

t re

Outdoor air load

Enthalpy

kJ/kg

Supply air

Room air

Air

conditioner

Lossnay Sensible HRV

Conventional

ventilator

Dry bulb temperature

Absolute humidity

Relative humidity

Enthalpy

26°C

27.6 27.6 33

14.8 20.3 20.3

63 86 63

65.4 79.2 85.0

(15.6) (18.9) (20.3)

3.3 1.0 0

(2,809) (831)

2.0 4.3 5.3

(1,749) (3,727) (4,558)

38.5 82 100

10.5 g/kg’

50%

53.2 kJ/kg (12.7 kcal/kg’)

Outdoor air

Exhaust air

Dry bulb temperature Absolute humidity Relative humidity

Enthalpy

33°C

20.3 g/kg’

63%

85.0 kJ/kg (20.3 kcal/kg’)

Dry bulb temperature (°C)

Absolute humidity (g/kg’)

Relative humidity (%)

Enthalpy

(kJ/kg)

(kcal/kg’)

Outdoor air load

(kW)

(kcal/h)

Outdoor air load ratio (%)

Total heat recovered

(kW)

(kcal/h)

* Calculated volume under below conditions.

(2) Heating during winter

Conditions:

●

Model LGH-50R type

●

Heat recovery efficiency table (%)

(at 50Hz, high speed) (For winter)

●

Ventilation rate: 500 m3/h (Specific gravity of air

= 1.2 kg/m3)

CHAPTER 3 ● General Technical Considerations

Lossnay Sensible HRV

Conventional

ventilator

Temperature

77 77 –

(sensible heat)

Enthalpy

67 44.2* –

(total heat)

Supply air

Room air

Air

conditioner

Lossnay Sensible HRV

Conventional

ventilator

Dry bulb temperature

Absolute humidity

Relative humidity

Enthalpy

20°C

15.4 15.4 0

4.6 1.8 1.8

43 17 50

27.4 19.8 5.0

(6.5) (4.7) (1.2)

3.7 2.4 0

(3,211) (2,121)

1.9 3.2 5.6

(1,591) (2,680) (4,802)

33 57 100

7.2 g/kg’

50%

38.5 kJ/kg (9.2 kcal/kg’)

Outdoor air

Exhaust air

Dry bulb temperature Absolute humidity Relative humidity

Enthalpy

0°C

1.8 g/kg’

50%

5.0 kJ/kg (1.2 kcal/kg’)

Dry bulb temperature (°C)

Absolute humidity (g/kg’)

Relative humidity (%)

Enthalpy

(kJ/kg)

(kcal/kg’)

Outdoor air load

(kW)

(kcal/h)

Outdoor air load ratio (%)

Total heat recovered

(kW)

(kcal/h)

●

Lossnay (Supply air diffuser temperature) tSA=

(20°C – 0°C) × 0.77 + 0°C = 15.4°C

(Supply air diffuser

enthalpy)

hSA=

(38.5 – 5.0) × 0.67 + 5.0

27.4 kJ/kg

Heat recovered (27.4 – 5.0) × 1.2 × 500

= 13,440 kJ/h = 3.7 kW (3,211 kcal/h)

Outdoor air load (38.5 – 27.4) × 1.2 × 500

6,660 kJ/h = 1.9 kW (1,591 kcal/h)

●

Sensible HRV (Supply air diffuser temperature) tSA=

(20°C – 0°C) × 0.77 + 0°C = 15.4°C

(Supply air diffuser

enthalpy)

hSA=

19.8 kJ/kg (4.7 kcal/kg’) (from psychrometric chart)

Heat recovered (19.8 – 5.0) × 1.2 × 500

= 8,880 kJ/h = 2.5 kW (2,121kcal/h)

Outdoor air load (38.5 – 19.8) × 1.2 × 500

= 11,200 kJ/h = 3.1 kW (2,681 kcal/h)

[Calculated enthulpy recovery efficiency 8,880 ÷ (8,880 + 11,200) × 100 = 44.2]

●

Conventional ventilator If a conventional ventilator is used, the supply air diffuser is the same as the outdoor air and the exhaust is the same as the room air. Thus the heat recovered is 0 kcal and the outdoor air load is (38.5 – 5.0) × 1.2 × 500 = 20,100 kJ/h = 5.6 kW (4,802 kcal/h)

Calculation example Winter conditions

hRA

iOA

tOA

tSA

15.4

tRA

RA 0.0072

XSA 0.0046

XOA 0.0018

hSA

38.5

5.6

27.4

Absolute humidity (kg/kg’)

Outdoor air

condition in

winter

Room air condition

in winter

Supply air condition

of the Lossnay

Dry bulb temperature (°C)

Lossnay

heat recovery

Outdoor air load

Enthalpy

kJ/kg

* Calculated volume under below conditions.

CHAPTER 3 ● General Technical Considerations

2. Example Heat Recovery Calculation

(1) Setting of conditions

(Note: Tokyo Power, industrial power 6 kV supply)

●

Return air volume (RA) = 7,200 m3/Hr

●

Outdoor air volume (OA) = 8,000 m3/Hr

●

Air volume ratio (RA/OA) = 0.9

●

Air conditions

(2) Selection of Lossnay model (select from treatment air volume catalogue)

●

Model name: LU-160 with combination of LU-1605 × 1 unit

●

Processing air volume per unit RA = 7,200 m3/Hr, OA = 8,000 m3Air volume ratio (RA/OA) = 0.9

●

Heat recovery efficiency : Heat recovery efficiency = 73%, Enthalpy recovery efficiency (cooling) = 62%,

Enthalpy recovery efficiency (heating) = 67%

●

tatic pressure loss (unit-type) RA = 156.9 Pa, OA = 186.3 Pa (Note: Each with filters)

●

Power consumption (pack-type) = none because of unit type

(3) State of indoor supply air

(4) Outdoor air load and heat recovered

(5) Recovered money (power rates)

Units When Heating When Cooling

Operation time (h/yr)

10h/day × 26 days/mo. × 5 mo./yr. = 1,300 h/yr 10h/day × 26 days/mo. × 4 mo./yr. = 1,040 h/yr

Electricity fee

(yen/kWh)

16.22 17.84

Capacity per

(kW/kW) 3.1 2.6

1 kW of electricity

Energy unit cost

(yen/kWh)

16.22/3.1 = 5.23 17.84/2.6 = 6.86

Season Winter heating Summer cooling

Item

Dry bulb temp. Wet bulb temp.

Relative humidity Absolute humidity

Enthalpy h Dry bulb temp. Wet bulb temp.

Relative humidity Absolute humidity

Enthalpy h

DB [°C] WB [°C] RH [%] × [kg/kg (DA)] [kJ/kg (DA)] DB [°C] WB [°C] RH [%] × [kg/kg (DA)] [kJ/kg (DA)]

Outdoors 0 –2.7 50 0.0018 5.0 (1.2) 33 27.1 63 0.0202

85.0 (20.3)

Indoors 20 13.8 50 0.0072 38.5 (9.2) 26 18.7 50 0.0105

53.0 (12.7)

Heating Cooling

= { 20 (Indoor temperature) – 0 (outdoor air temperature)} × = 33

(Outdoor air temperature) – { 33 (outdoor air temperature) –

Temperature [°C] 0.73 (heat recovery efficiency) + 0 (outdoor air temperature) 26 (indoor temperature)} × 0.73 (heat recovery efficiency)

= 14.6 = 27.89

Enthalpy

= {38.5 (Indoor enthalpy) – 5.0 (outdoor air enthalpy)} × = 85 (Outdoor air enthalpy) – { 85 (outdoor air enthalpy) –

[kJ/kg (DA)]

0.67 (enthalpy recovery efficiency) + 5.0(outdoor air enthalpy)

53.2

(indoor enthalpy)} × 0.62 (enthalpy recovery efficiency)

= 27.4 = 65.3

Numerical value obtained •Dry-bulb temperature = 14.6 °C •Wet-bulb temperature = 9.2 °C•Dry-bulb temperature = 27.89 °C •Wet-bulb temperature = 22.4 °C

from above equation and •Relative humidity = 49% •Absolute humidity = 0.005 kg/kg (DA)•Relative humidity = 62% •Absolute humidity = 0.0146 kg/kg (DA)

psychometric chart

•

Enthalpy = 27.4 kJ/kg (DA)

•

Enthalpy = 65.3 kJ/kg (DA)

Heating Cooling

Fresh air load without

= 1.2 (Air specific gravity) × 8,000 (outdoor air volume) × = 1.2 (Air specific gravity) × 8,000 (outdoor air volume) ×

Lossnay (q

{ 38.5 (indoor enthalpy) – 5.0 (outdoor air enthalpy) } { 85.0 (outdoor air enthalpy) – 53.2 (indoor enthalpy) }

= 321,600 kJ/h = 89.3 kW = 305,280 kJ/h = 84.8 kW

= 89.3 (Outdoor air load) (q

1) × = 84.8 (Outdoor air load) (q1) ×

Outdoor air load with

{ 1 – 0.67 (enthalpy recovery efficiency)} { 1 – 0.62 (enthalpy recovery efficiency) }

Lossnay (q

= 29.5kW = 32.2 kW

or or

Air specific gravity × outdoor air volume × (indoor enthalpy – indoor blow enthalpy)= Air specific gravity × outdoor air volume × (indoor enthalpy – indoor blow enthalpy)

= q

– q2 = q1 – q2

= 89.3 – 29.5 = 84.8 – 32.2

Heat recovered (q

= 59.8 = 56.2 kW

or or

= Outdoor air load (q1) × enthalpy recovery efficiency = Outdoor air load (q1) × enthalpy recovery efficiency

•

Outdoor air load = 89.3 kW = 100%

•

Outdoor air load =84.8 kW = 100%

(%) outdoor air load•Outdoor air load with Lossnay = 29.5 kW = 33%

•

Outdoor air load with Lossnay = 32.2 kW = 38%

•

Heat recovered = 59.8 kW = 67%

•

Heat recovered = 52.6 kW = 62%

Heating Cooling

Heat recovered: kW ×Unit price yen/W ×operation time Hr/year = Heat recovered: kW × Unit price yen/W × operation time Hr/year

Yearly saved money = 59.8 kW × 5.232 yen/kWh × (1,300hr/year) = 52.6 kW × 6.86 yen × (1,040hr/year)

= 406,580 yen = 375,269 yen

Remarks If recovered heat is converted to electricity : heating = 59.8 kW/3.1 = 19.3 kW/h cooling = 52.6 kW/2.6 = 20.2 kW/h

Caution: See the psychrometric chart on the next page.

CHAPTER 3 ● General Technical Considerations

●

Psychrometric chart for calculating Lossnay economical effect

The following can be determined from the above calculation results:

●

Saving of 59.8 kW of the heating load, and 52.6 kW of the cooling load is possible. The heat source equipment and related ventilator capacity that is equivalent to this saved amount can be reduced, thus the operation and maintenance costs can also be saved.

●

Approximately 400,000 yen can be saved in operation and maintenance costs during heating and 370,000 yen during cooling, for a total savings of approximately 770,000 yen. Furthermore, as 20.2 kW can be saved from the basic power rates during cooling, approximately 370,000 yen (20.2 × 1,560 yen/month × 12 months) can be saved annually.

27.4

38.5

53.2

65.3

85.0

5.0

0 14.6 20 26 33

0.0018

0.005

0.0072

0.0105

0.0146

0.0203

27.89

0.00.000

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.010

0.011

0.012

0.013

0.014

0.015

0.016

0.017

0.018

0.019

0.020

0.021

0.022

0.023

0.024

0.025

0.026

0.027

0.028

0.029

0.030

0.031

0.032

0.033

0.034

0.035

0.036

0.037

0.1

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

T.FUJITA

1987

VaporpressurePw[kPa]

Absolutehumidity x [kg/kg(DA)]

50494847464544434240 41393837363534333230 31292827262524232220 21191817161514131210 11987654320–1–2–3–4–9–10

0.75 0.76 0.77 0.78 0.79 0.80 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.90 0.91

–7–8 –5–6 1

–

–5

–

∞

–

400

40000

20000

15000

10000

4500

3800

–20000

–10000

–

5000

–2000

–

–500

500

1000

1200

1400

1800

2000

2200

2400

2600

3000

3200

3600

1.0

0.8

0.7

0.5

0.4

Comparativeenthalpy

h[kJ/kg(DA)]

Humid air psychrometric chart

(-10 to +50°C, atmospheric pressure 101.325 kPa)

eatw

aterra

tio

u = ––

[kJ/kg]

Sensibleheatratio

SFH

tio



]

0.94

0.92

0.93

0.96

0.95

Wetbulbtemperaturet'[°C]

Drybulbtemperaturet[°C]

Relativehum

idity

]

ille

Water

Specificcapacityv [m

/kg(DA)]

CHAPTER 3 ● General Technical Considerations

3. Calculation of Lossnay Economical Effects

The following is a sample questionnaire from which it is possible to assess the economical benefits of using the Lossnay in particular applications.

(1) Setting of conditions

●

Return air volume (RA) = m3/Hr

●

Outdoor air volume (OA) = m3/Hr

●

Air volume ratio (RA/OA) =

●

Air conditions

●

Operation time: Heating = hours/day × days/month × months/year = hours/year

Cooling = hours/day × days/month × months/year = hours/year

●

Energy: Heating = Type: Electricity Cost: ¥ /kWh

Cooling = Type: Electricity Cost: ¥ /kWh Power rates: Winter: ¥/kWh Summer: ¥ /kWh

(2) Selection of Lossnay model (select from treatment air volume catalog)

●

Model name:

●

Processing air volume per unit RA = m3/Hr, OA = m3, Air volume ratio (RA/OA) =

●

Heat recovery efficiency :

Heat recovery efficiency = %, Enthalpy recovery efficiency (cooling) = %, Enthalpy recovery efficiency (heating) = %

●

Static pressure loss (unit-type) RA= mm H

2O OA = mm H

2O (Note: Each with filters)

●

Power consumption (pack-type) = none because of unit type

(3) State of indoor blow air

Season Winter heating Summer cooling

Dry bulb Wet bulb Relative Absolute Enthalpy Dry bulb Wet bulb Relative Absolute Enthalpy

Item temp. temp. humidity humidity i kJ/kg temp. temp. humidity humidity i kJ/kg

DB [°C] WB [°C] RH [%] × [kg/kg’] (kcal/kg’) DB [°C] WB [°C] RH [%] × [kg/kg’] (kcal/kg’)

Outdoors

Indoors

Heating Cooling

= (Indoor temperature – outdoor air temperature) × = Outdoor air temperature – (outdoor air

Temperature [°C]

heat recovery efficiency + outdoor air temperature – indoor temperature) × temperature heat recovery efficiency

= (Indoor enthalpy – outdoor air enthalpy) × = Outdoor air enthalpy – (outdoor air Enthalpy enthalpy recovery efficiency + outdoor air enthalpy – indoor enthalpy) × [kJ/kg(kcal/kg)] enthalpy enthalpy recovery efficiency

Numerical value

●

Dry-bulb temperature = °C

●

Dry-bulb temperature = °C

obtained from above

●

Wet-bulb temperature = °C

●

Wet-bulb temperature = °C

equation and

●

Relative humidity = %

●

Relative humidity = %

psychometric chart

●

Absolute humidity = kg/kg’

●

Absolute humidity = kg/kg’

●

Enthalpy = kg/kg

(kcal/kg)●Enthalpy = kg/kg

(kcal/kg)

CHAPTER 3 ● General Technical Considerations

(4) Outdoor air load and heat recovery

Heating Cooling

Fresh air load without

= Air specific gravity × outdoor air volume = Air specific gravity × outdoor air volume

Lossnay (q

× (indoor enthalpy

–

outdoor air enthalpy) × (outdoor air enthalpy – indoor enthalpy)

= Outdoor air load (q

1) = Outdoor air load (q1)

× ( 1 – enthalpy recovery efficiency) × ( 1 – enthalpy recovery efficiency) Outdoor air load with = = Lossnay (q

)or or

= Air specific gravity × outdoor air volume = Air specific gravity × fresh air volume

× (indoor enthalpy

–

indoor blow enthalpy) × (indoor blow enthalpy – indoor enthalpy)

–

q2 =q1

–

Heat recovery (q3)

or or

= Outdoor air load (q

1) = Outdoor air load (q1)

× enthalpy recovery efficiency × enthalpy recovery efficiency

● Outdoor air load = W = % ● Outdoor air load = W = %

(%) to outdoor air

● Outdoor air load with Lossnay ● Outdoor air load with Lossnay

load = W = % = W = %

● Heat recovered = W = % ● Heat recovered = W = %

(5) Recovered money (power rates)

Heating Cooling

Heat recovered: kW × Unit price ¥/kWh ×

Yearly saved money

operation

time Hr/year = kW ×¥/

kWh

operation

time Hr/year = kW ×¥/

kWh

= Hr/year = Hr/year ==

+ 108 hidden pages