ALFAMINI-ALFAMAX Central Station air handling units high efficiency for wellness areas 1
The plants are quite complex and, therefore, "Fascinating from engineering point of view Conditioning plants are setup for Full air" 2
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 3
It s important to "act" on the insulation of the building: good external insulation adequate vapor barrier avoid air infiltration and thermal bridge 4
The air distribution system (ducts mainly) is designed with particular attention to: ensuring speed on the surface of the water below certain values avoid dangerous standing" air 5
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 6
The atmosphere is particularly aggressive (Presence of chlorine). Issues: 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 contact with "aggressive air 7
The corrosive atmosphere of chlorinated attacks via pitting: - It is a localized corrosion - Even materials such as stainless steel (behavior electrochemical l active) in the presence of chloride ions, can be attacked locally in their passivating layer - The corrosive o action is also a function of temperature 8
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 9
Extreme variability of application 10
Plants are "energy-intensive" i " 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 11
- The plants operate virtually 24h per day (possibility of reduced d performance) - Hygiene requirements for the pool water stands that tthe water must tbe replaced with new one (minimum 5% of the volume of each tank day) - High consumption of hot water for sanitary use The cost of energy required to operate the pool can easily exceed 30-35% of the total cost of ownership 12
Distribution of energy consumption: - Pool water heating necessary compensate for: Evaporation losses Losses due to transmission i through h the walls and the bottom of the tank - Changing the water - "Air" through the local (Usually leakage through h the envelope does not exceed 20% the overall energy requirements) - Sanitary water heating 13
Improvements to reduce consumption MUST ACT ON ITEMS THAT HAVE THE GREATEST IMPACT on the Energy consumption that is: - Water heating - "Air" of the pool 14
How? Using efficient equipment for the treatment air (and water), with energy recovery from the exhaust air maintaining a fine control of air temperature maintaining a fine control of water temperature keeping the temperature control hot water (Small savings) 15
applying a cover to the tank (less evaporation, heat-up time fast but problems of obstacles in the mirror of water) 16
Using solar energy (pay attention ti to corrosion: double circuit with heat exchanger intermediate) Recovering the heat contained in the lost water Installing effective systems of supervision and consumption monitoring 17
Some considerations on the conditions indoor climate: RELATIVE HUMIDITY: - The higher its value, the less result of the evaporation ponds and then the latent load to be removed. - The higher its value, the less Evaporation is the body, and then temperatures may be acceptable ab e environment e closer to that of water 18
Some considerations on the climate indoor conditions TEMPERATURE OF THE WATER TANK: - It affects the feeling of wellness in the pool - It impacts on the feeling and the exiting environment - It affects the performance of athletes (for races, they prefer a relatively low temperature) 19
Some considerations on the conditions indoor climate: VELOCITY of AIR - The residual velocity of air at the level of tank affects evaporation which can be higher - Rapid evaporation of the water film on the body resulting in feeling cold 20
In these circumstances you can imagine that it is a MUST to design system solutions and applications to obtain: the environmental comfort (users) the saving energy needing (managers) 21
Project data Internal air temp ( C) Internal air RH (%) Water temp( C) 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) 22
The basic needed data are: Recommended room size: (length + 4m + 4m) x (width+25m+25m) 2.5m + 2.5m) Application of negative pressure in the room pool Air flow: 50 m3 / h for each square meter of water surface Example: Tank 25m x 16m = 400 m2 Total air flow rate = 400 x 50 cm / h = 20,000 000 m³ / 23
The basic data are: Minimum replacement of air flow : 9m3/ h for each square meter of surface area of the room (ASHRAE and UNI 10339) - There are other indications (Conference Permanent State-Regions): 20 m3 / h for each square meters of tank (excessive) - In general it is good to be around 30% of nominal 24
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 the platform for diving 25
ASHRAE (USA): Takes care of direct evaporation of the water in the tank depending of degree of use Takes care of activity of people Pool Usage factor Residential 0,50 Fitness 0,65 Therapy 0,65 Hotel 0,80 Schools 0,80 Public pools 1,00 Therma centers 1,00 Thermal loaduponpeople Activity kg/h lb/h Sit down, relax 0,05 0,1 Sit down, very light job 0,07 0,15 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 Light fitness 038 0,38 083 0,83 Fitness, medium activity 0,42 0,92 Athletes 0,47 1,04 26
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 27
Airflows m3/h 2500 4000 6000 10000 16000 20000 25000 30000 Pool surface (50 m3/h perm2) m2 50 80 120 200 320 400 500 600 Condensation generated by pool Ac=27; Ar=29 60 VDI 2089 Beta=7 Condensation generated by pool Ac=27; Ar=29 60 VDI 2089 Beta=21 Condensation generated by pool Ac=27; Ar=29 60 VDI 2089 Beta=28 Condensation generated by pool Ac=27; Ar=29 60 VDI 2089 Beta=40 Condensation generated by pool Ac=27; Ar=29 60 VDI 2089 Beta=50 kg/h 3.1 5.0 7.4 12.4 19.8 24.8 31.0 37.2 kg/h 93 9.3 14.8 22.22 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 70.4 112.6 140.8 176.0 211.2 kg/h 22.1 35.3 52.9 88.2 141.1 176.4 220.5 264.6 Condensation generated by pool Ac=27; kg/h 8.8 14.1 21.2 35.3 56.4 70.6 88.2 105.8 Ar=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; kg/h 4.4 7.1 10.6 17.6 28.2 35.3 44.1 52.9 Ar=29 60 ASHRAE FU=0.5 Private 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 93 9.3 14.8 22.22 37.0 59.2 74.0 92.5 111.0 28
The basic concepts for the sizing of AHUs are: - dehumidification with minimum i cost (= using external air) - Recover energy by the exhaust air (PHE + Pdc) With the above assumptions, we understand that: THE PROJECT IS STRONGLY INFLUENCED BY OUTSIDE AIR TEMPERATURE 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 29
Target Pool air temperature: + / - 1 C above the water temperature (typically 27/28 C+1 C) C) Relative humidity: - 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 heat If the pool is used having outside air temperatures >29 C, it is necessary to cool down and dispose / recover through water in case compressors are present 30
3. Dehumidification via compressor 4. Dehumidification via compressor, cooling via compressor 1. Dehumidification via fresh air 2. Dehumidification via air, cooling via compressor 31
1. Dehumidification via fresh air Typical, no compressors Humidity 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) 32
2. Dehumidification via air, cooling 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 from 6 to about 9 (COP = 6 when retrieves a lot of power and COP = 9 when you retrieve little power). 33
In any case, the key point is the recovery that has to be large enough to get as much energy as possible by the pool itself: recovery offests the differences temperature between indoors and outdoors. 34
Normal, outside air modulating: P o o l Simulations on AHUs from 25,000 m³ / h, to offset 160 kg / h (ASHRAE method, pool 504 square meters, 128 swimmers, track and field activities) the limit of outside air temperature is about 24 C with the 65% RH (in case it s over, you need to open windows) O u t s i d e 35
Cycle extension of the field work 21 to 26 C outside: P o o l Outside 36
Approximate trend % outside air a (%) Aria esterna Tariaesterna( C) 37
Trend for RH, and COP 38
Trend for Power W) Po otenza (k Potenza richiesta dall edificio Potenza termica batteria post-risc Potenza termica da integrare/smaltire T aria esterna ( C) 39
mandatory Necessary to know Not mandatory but useful for better offer 40
Sizes: Airflow (m3/h) 2.500 4.000 6.300 AlfaMini 10.000 13.000 16.000 20.000 25.000 AlfaMax Small-medium applications Medium-large applications 41
Product Features: - 5 sizes available - Anodized aluminum frame - Internal surfaces fully painted - Cross flow heat recovery, fully painted -Refrigerant fluid R410A, separate from the air flow - Hot water heating coil with 3-way valve, as standard 42
Product Features: - Plug fans with inverter, as standard - Return filters G4, supply filters G4 + F9 - Plug & play unit (microprocessor and power cabinet as standard) d) - Water-Water heat exchanger, to give exceeding power to pool water as standard 43
Summary of features: 44
Cycles of operation: "Setting up the system" 45
Cycles of operation: "Dehumidification via fresh air" 46
Cycles of operation: "Dehumidification via fresh air and alpha cycle " Indice 47
Cycles of operation: Night mode" 48
Cycles of operation: "Transferring of heat to the water" 49
Product Features: - 3 sizes available - Anodized 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 with 3-way valve, as standard d 50
Product Features: - Plug fans with inverter, as standard - Return filters G4, supply filters G4 + F9 - Plug & play unit (microprocessor and power cabinet as standard) d) - Water-Water heat exchanger, to give exceeding power to pool water as standard 51
Summary of features: 52
Cycles of operation: "Setting up the system" 53