Home | Arfit - Indice...Ar=29‐60 VDI 2089 Beta=28 kg/h 12.4 19.8 29.6 49.4 79.0 98.8 123.5 148.2 Condensationgeneratedby pool Ac=27; Ar=29‐60 VDI 2089 Beta=40 kg/h 17.6 28.2 42.2

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ALFAMINI-ALFAMAXCentral Station air handling units high efficiency for wellness areas

1Copyright © 2010 - FAST SpA

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• The plants are quite complex and, therefore, "Fascinating“ fromFascinating from engineering point of viewof view

• Conditioning plants are setup for “Full air"


• We need to carefully evaluate the loads due to:

- Need of dehumidification - The building thermal load


• We need to properly evaluate the actual condition of using the pool

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It‘s important to "act" on the insulation of the building: • good external insulation • adequate vapor barrier • avoid air infiltration and thermal bridgeg


The air distribution system (ducts mainly) is designed with particular attention to: g p

• ensuring speed on the surface of the• ensuring speed on the surface of the water below certain values

• avoid dangerous “standing" air


The best solution is: - Return air from the top (above the bathtub) - Send air near the windows and

condensation risky elements- Prevent the phenomena of radiant

asymmetry - Monitor the relative humidity


The atmosphere is particularly aggressive (Presence of chlorine)of chlorine). Issues: • the chemical composition of the vapor is variable• the chemical composition of the vapor is variable • materials that stand up well to corrosion when submerged in water may not be so if in contactsubmerged in water may not be so if in contact with "aggressive air”


The corrosive atmosphere of chlorinated attacks via pitting:p g- It is a localized corrosion - Even materials such as stainless steel (behavior

l t h i l ti ) i th f hl id ielectrochemical active) in the presence of chloride ions, can be attacked locally in their passivating layer

- The corrosive action is also a function of temperatureo o a o a o a u o o p a u


Another aspect often overlooked in planning is the identification of appropriate technical areas:- Ensure, at a minimum, access to units for

maintenance - Physically separate, if possible, areas with

presence of chlorinated air from the "normal"

Often the technical areas are used as warehouse for disinfectants, materials cleaning, etc


Extreme variability of application


l " i i " d h fPlants are "energy-intensive" due to the fact that:

- The temperature / humidity of air is "special" - The temperature of the pool (=water tank)

must be kept almost always constant (high thermal inertia)

- The volumes of pools are very big


- The plants operate virtually 24h per day ( ibilit f d d f )(possibility of reduced performance) - Hygiene requirements for the pool water t d th t th t t b l d ithstands that the water must be replaced with

new one (minimum 5% of the volume of each tank day)tank day) - High consumption of hot water for sanitary useuse

The cost of energy required to operate the pool can easily exceed 30-35% of the total cost

f hi12

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of ownership

Distribution of energy consumption: - Pool water heating necessary compensate for:

Evaporation losses L d t t i i th h thLosses due to transmission through the walls and the bottom of the tank

Ch i h- Changing the water - "Air" through the local (Usually leakage

h h h l d d 20through the envelope does not exceed 20% the overall energy requirements)

- Sanitary water heating


Improvements to reduce consumptionImprovements to reduce consumptionMUST ACT ON ITEMS THAT HAVE THE GREATEST IMPACT on the Energy consumptionIMPACT on the Energy consumptionthat is:

- Water heating - "Air" of the pool


How? • Using efficient equipment for the treatment air (and water), with energy recovery from the ( ), gy yexhaust air • maintaining a fine control of air temperature g p• maintaining a fine control of water temperature p• keeping the temperature control hot water (Small savings)


• applying a cover to the tank (less evaporation• applying a cover to the tank (less evaporation, heat-up time fast but problems of obstacles in the mirror of water)the mirror of water)


U i l ( tt ti t i• Using solar energy (pay attention to corrosion: double circuit with heat exchanger intermediate)intermediate)

• Recovering the heat contained in the lost water

• Installing effective systems of supervision and consumption monitoring


Some considerations on the conditions indoorSome considerations on the conditions indoor climate: RELATIVE HUMIDITY:RELATIVE HUMIDITY: - The higher its value, the less result of the evaporation ponds and then the latent load toevaporation ponds and then the latent load to be removed. - The higher its value the less Evaporation isThe higher its value, the less Evaporation is the body, and then temperatures may be acceptable environment closer to that of wateraccep ab e e o e c ose o a o a e


•Some considerations on the climate indoorSome considerations on the climate indoor conditions

TEMPERATURE OF THE WATER TANK: It affects the feeling of wellness in the pool- It affects the feeling of wellness in the pool

- It impacts on the feeling and the exiting environmentenvironment - It affects the performance of athletes (for races they prefer a relatively low temperature)races, they prefer a relatively low temperature)


Some considerations on the conditions indoorSome considerations on the conditions indoor climate:

VELOCITY of AIRThe residual velocity of air at the level of- The residual velocity of air at the level of

tank affects evaporation which can be higherRapid evaporation of the water film on the- Rapid evaporation of the water film on the

body resulting in feeling cold


In these circumstances you can imagine that itis a MUST to design system solutions andapplications to obtain:

• the environmental comfort (users)

• the saving energy needing (managers)


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• Project data

Internal air temp (°C) Internal air RH (%) Water temp(°C)

Project data

Type of pool da a da a da a

Recreational 24 30 60 56 24 30

Therapeutic 27 29 50 60 29 35

Competition 26 29 50 60 24 28

Diving 27 29 50 60 27 32

Whirpools 27 29 50 60 36 40

(Source: ASHRAE Applications Handbook and Humidity


Control Design Guide)

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The basic needed data are:

• Recommended room size: (length + 4m + 4m) x (width + 2 5m + 2 5m)(width + 2.5m + 2.5m)

• Application of negative pressure in the room pool

• Air flow: 50 m3 / h for each square meter of water surfacesurface

Example: Tank 25m x 16m = 400 m2 Total air flow rate = 400 x 50 cm / h = 20 000 m³ /Total air flow rate = 400 x 50 cm / h = 20,000 m /


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The basic data are:

• Minimum replacement of air flow : 9 m3 / h for each square meter of surface area of the9 m3 / h for each square meter of surface area of the room (ASHRAE and UNI 10339)

Th th i di ti (C f P t- There are other indications (Conference Permanent State-Regions): 20 m3 / h for each square meters of tank (excessive)tank (excessive)

- In general it is good to be around 30% of nominal


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The basic data are:The basic data are:

• Ventilation rate (volume / h recommended): between 6 and 9 times the internal volume as a function also of presence or absence of infrastructure for audience

• Air velocity on the surface of the water less than 0.10 m / s (if it is particularly sensitive parameter provided h l f f dthe platform for diving


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ASHRAE (USA):

• Takes care of direct evaporation of the water in the tank depending of degree of use

Pool Usage factorThermal load upon peopleActivity kg/h lb/h

• Takes care of activity of people

Residential 0,50

Fitness 0,65

Therapy 0,65

Hotel 0,80

Sit down, relax 0,05 0,1

Sit down, very light job 0,07 0,15

Hotel 0,80

Schools 0,80

Public pools 1,00

Therma centers 1,00

Sit down, light job 0,09 0,2

Stand up, walking 0,11 0,24

Light dance 0,24 0,52

Walking hard 0,27 0,6

Li ht fit 0 38 0 83

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Light fitness 0,38 0,83

Fitness, medium activity 0,42 0,92

Athletes 0,47 1,04Copyright © 2010 - FAST SpA

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Other norms:Other norms:- SWKI (Switzerland)- VDI (Germany)- …

It is common though that the ASHRAE method can be precise and give the opportunity to fine-tune the machine compared to the needing


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Airflows m3/h 2500 4000 6000 10000 16000 20000 25000 30000

Pool surface (50 m3/h per m2) m2 50 80 120 200 320 400 500 600Pool surface (50 m3/h per m2) m2 50 80 120 200 320 400 500 600

Condensation generated by pool Ac=27; Ar=29‐60 VDI 2089 Beta=7

kg/h 3.1 5.0 7.4 12.4 19.8 24.8 31.0 37.2

Condensation generated by pool Ac=27; kg/h 9 3 14 8 22 2 37 0 59 2 74 0 92 5 111 0

g y pAr=29‐60 VDI 2089 Beta=21

kg/h 9.3 14.8 22.2 37.0 59.2 74.0 92.5 111.0


kg/h 12.4 19.8 29.6 49.4 79.0 98.8 123.5 148.2


kg/h 17.6 28.2 42.2 70.4 112.6 140.8 176.0 211.2Ar=29‐60 VDI 2089 Beta=40Condensation generated by pool Ac=27; Ar=29‐60 VDI 2089 Beta=50

kg/h 22.1 35.3 52.9 88.2 141.1 176.4 220.5 264.6

Condensation generated by pool Ac=27; A 29 60 ASHRAE FU 1 P bbli h

kg/h 8.8 14.1 21.2 35.3 56.4 70.6 88.2 105.8Ar=29‐60 ASHRAE FU=1 Pubbliche

Condensation generated by athletes kg/h 3.9 3.9 3.9 3.9 3.9 3.9 3.9 3.9

TOTAL CONDENSATION ASHRAE kg/h 16.0 25.6 38.4 64.0 102.4 128.0 160.0 192.0

Condensation generated by pool Ac=27; Ar=29‐60 ASHRAE FU=0.5 Private

kg/h 4.4 7.1 10.6 17.6 28.2 35.3 44.1 52.9

Condensation generated by athletes kg/h 5.8 5.8 5.8 5.8 5.8 5.8 5.8 5.8

TOTAL CONDENSATION ASHRAE kg/h 9 3 14 8 22 2 37 0 59 2 74 0 92 5 111 0

28

TOTAL CONDENSATION ASHRAE kg/h 9.3 14.8 22.2 37.0 59.2 74.0 92.5 111.0

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The basic concepts for the sizing of AHUs are:d h idifi ti ith i i t ( i t l- dehumidification with minimum cost (= using external

air) - Recover energy by the exhaust air (PHE + Pdc)gy y ( )

With the above assumptions, we understand that:• THE PROJECT IS STRONGLY INFLUENCED BY

OUTSIDE AIR TEMPERATURE• IT’S NECESSARY TO KNOW THE MAXIMUM EXTERNAL• IT S NECESSARY TO KNOW THE MAXIMUM EXTERNAL

TEMPERATURE WHICH THE POOL WILL WORK DURING (of course with the windows closed)

• TO AVOID ANY UNNECESSARY OVERSIZED UNIT, EVERY MACHINE HAS HIS OWN LIMIT OF FRESH AIR


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Target

• Pool air temperature: + / - 1 ° C above the water temperature (typically 27/28°C+1°C)water temperature (typically 27/28 C+1 C)

• Relative humidity:y- 50 to 60% optimal- Maximum acceptable 65% RH (over 65%,

you feel the sensation of sultriness)So• Up to an outside temperature of 29 ° C we always must• Up to an outside temperature of 29 C, we always must

heat• If the pool is used having outside air temperatures >29 °

C it is necessary to cool down and dispose / recover


C, it is necessary to cool down and dispose / recover through water in case compressors are present

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4 Dehumidification4 . Dehumidificationvia compressor,cooling via compressor

3 Dehumidification3 . Dehumidificationvia compressor

1. Dehumidification2 . Dehumidificationvia air,

via fresh air cooling via compressor


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1. Dehumidificationvia fresh airvia fresh air

T i lTypical, no compressors

Humidity is controlled to a Text of 21 ° C modulating theHumidity is controlled to a Text of 21 C, modulating the flow of outside air from 0% up to 100%.

The RH inside "drift" up to 65% with Text around 24 ° C (maximum operating limit)


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2 . Dehumidification via air,cooling via compressorcooling via compressor

It‘ s a solution similar to previous but it includes a refrigerant circuit with the function of energy recovery.

The dehumidification works, as before, modulating the flow of outside air from 0% to 100%

By sizing the cooling system and its workflow we may decide to condense in the water with COP ranging fromdecide to condense in the water with COP ranging from 6 to about 9 (COP = 6 when retrieves a lot of power and COP = 9 when you retrieve little power).


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In any case, the key point is the recovery that has to be largerecovery that has to be large enough to get as muchenergy as possible by the poolenergy as possible by the pool itself: recovery offests the differences temperature betweendifferences temperature between indoors and outdoors.


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Normal, outside air modulating:

Po

Ou

ol

tsiidee

Simulations on AHUs from 25,000 m³ / h, to offset 160 kg / h (ASHRAE method pool160 kg / h (ASHRAE method, pool504 square meters, 128 swimmers, track and field activities) the limit of outside air temperature


) pis about 24 ° C with the 65% RH (in case it’s over, you need to open windows)

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Cycle extension of the field work

Outside

21 to 26 ° C outside:

P

Outside

ooll


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Approximate trend % outside air

a (%

)a

este

rna

Ari

T aria esterna (°C)


T aria esterna (°C)

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Trend for RH, and COP


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Trend for Power

kW)

kW)

Potenza richiesta dall’edificio

oten

za (

kot

enza

(k

Potenza termica batteria post-risc

PoPo Potenza termica da integrare/smaltire

T aria esterna (°C)T aria esterna (°C)


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mandatory

N t k

40

Necessary to know

Not mandatory but useful for better offerCopyright © 2010 - FAST SpA

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Sizes:

Airflow (m3/h)

2.500

4.000

6 300 AlfaMini Small-medium6.300

10.000

13.000

AlfaMini applications

16.000

20.000

25 000

AlfaMax Medium-largeapplications

25.000


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Product Features:

- 5 sizes available- Anodized aluminum frame- Anodized aluminum frame- Internal surfaces fully painted- Cross flow heat recovery,Cross flow heat recovery, fully painted- Refrigerant fluid R410A, g ,separate from the air flow- Hot water heating coil with3-way valve, as standard


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Product Features:

- Plug fans with inverter, as standard- Return filters G4 supply filters G4 + F9Return filters G4, supply filters G4 + F9- Plug & play unit (microprocessor and powercabinet as standard)cab et as sta da d)

- Water-Water heat exchanger to giveexchanger, to give exceeding power to pool water asto pool water as standard


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Summary of features:Summary of features:


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Cycles of operation:"Setting up the system"


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Cycles of operation:"Dehumidification via fresh air"


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Cycles of operation:"Dehumidification via fresh air and alpha cycle "


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Cycles of operation:“Night mode"


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Cycles of operation:"Transferring of heat to the water"


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Product Features:Product Features:- 3 sizes available- Anodized aluminum frameAnodized aluminum frame- Internal surfaces fully painted- Double cross flow heat exchanger, fully painted- Refrigerant fluid R410A, separate from the air flow- Hot water heating coil with3 l t d d3-way valve, as standard


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Product Features:Product Features:- Plug fans with inverter, as standard- Return filters G4 supply filters G4 + F9Return filters G4, supply filters G4 + F9- Plug & play unit (microprocessor and powercabinet as standard)cab et as sta da d)

- Water-Water heat exchanger to giveexchanger, to give exceeding power to pool waterto pool wateras standard


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Summary of features:Summary of features:


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Cycles of operation:"Setting up the system"


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Documents

Home | Arfit - Indice...Ar=29‐60 VDI 2089 Beta=28 kg/h 12.4 19.8 29.6 49.4 79.0 98.8 123.5 148.2 Condensationgeneratedby pool Ac=27; Ar=29‐60 VDI 2089 Beta=40 kg/h 17.6 28.2 42.2