Detta examensarbete har som syfte att inventera och jämföra utlokaliseringsbara kylmaskiner för Umeå Energis räkning. Umeå Energi levererar fjärrvärme och fjärrkyla till Umeå stad. Fjärrkylanätet som idag distribuerar fjärrkylan har byggts ut för att möta ett ökat framtida kylbehov. Det kommer trotts utbyggnaden finnas potentiella kunder som inte kan ansluta till fjärrkylanätet men som samtidigt redan är anslutna till fjärrvärmenätet. Nuvarande fjärrkyla produceras vid centraliserade anläggningar med fjärrvärme i högtemperaturdrivna absorptionskylmaskiner. Som konsekvens medför detta att temperaturen i fjärrvärmevattnet måste hållas tillräckligt hög för att kunna driva absorptionskylmaskinerna. Därigenom blir även temperaturen ute i fjärrvärmenätet förhållandevis hög. Detta möjliggör i sin tur drift av lågtemperaturdrivna kylmaskiner ute på platts hos de kunder som inte har möjlighet att ansluta till fjärrkylanätet. Under sommaren, då störst kylbehov föreligger, står en större avfallspanna för värmehållningen i fjärrvärmenätet. Umeå Energi får betalt för att elda avfall vilket innebär att driftskostnaderna för drivenergin till de egna värmedrivna kylmaskinerna blir mycket låg. I jämförelsen som gjorts har värmedrivna och icke värmedrivna kylalternativ undersökts genom ett livscykelkostnadsperspektiv utifrån likvärdiga förutsättningar. Investeringskostnad och driftdata har inventerats från olika leverantörer och genom kontakt med tekniskt insatta. Kostnaden för de övriga åtgärder som krävs för att få maskinerna driftklara, har beräknats utifrån givna produktdata, referenser till andra projekt samt resonemang. Jämförelsen har utgått ifrån att det enda som krävts för att få maskinerna i drift är elinstallation, framdragning av rör till befintlig maskinlokal, att fjärrvärme, råvatten och el etc. redan finns i byggnaden. Den lösning som visat sig mest kostnadseffektiv är frikyla, strömmande vatten från borrhål samt bergkyla där en bergvärmeanläggning redan finns. Detta för att installations och driftskostnaderna är låga. De värmedrivna kylmaskiner som undersökts är främst absorptionskyla och sorptiv kyla som påverkas mycket av bränslepriset under driftsperioden, lasten, samt kundens effektbehov. Stora komfortkylankunder är lönsamma vid självkostnadspris för fjärrvärmen eftersom deras last är som störst då drivvärmen är som billigast under sommarhalvåret. Absorptionsmaskiner är intressanta från och med ca 600 kW kyleffekt för dessa kunder. Sorptiv kyla kan vara intressant i hela sitt effektomfång men endast om behandlingen av ventilationsluften vägs in. Vid rörligt el och fjärrvärmepris är kompressorluftkyla svårslagen tack vare aggregatets flexibilitet. Om den som skall kyla har ett stort kylbehov och redan äger mark är snökylning ett möjligt alternativ. Erfarenheten av snökyla är dock begränsad eftersom endast ett fåtal sådana anläggningar byggts i Sverige.  I denna rapport ges en fingervisning om vilka kylalternativ som är intressanta för utlokaliserad kylproduktion ur Umeå Energis respektive kundens perspektiv. / This thesis aims to examine and compare decentralized chillers for the behalf of Umea Energi. Umea Energi supplies district heating and district cooling to the city of Umea. The district cooling network that distributes the district cooling has been expanded to meet increased future cooling needs. Despite the recent expansion there is still potential customers who cannot join the district cooling network, even though they are already connected to the district heating network. Currently district cooling is produced using district heat in high temperature driven absorption chillers at centralized facilities and then distributed through a district cooling network. This leads to the consequence that the temperature of heating water from the heating plant must be kept high enough to enable the absorption chiller to operate. This causes the temperatures in the district heating network to be relatively high. This in turn permits the operation of low temperature heat driven chillers to produce cooling on site for those customers who are unable to join the district cooling network. During the summer when there is a greater cooling demand, all district heat is produced by a waste disposal boiler. Because Umeå Energi receives payment for burning and disposal of the waste, the operational and fuel costs for the energy needed to operate the chillers becomes very low. In the comparison made in this report heat-driven and non-heat-driven chillers have been studied from a lifecycle cost perspective based on equal presumptions for the different chiller alternatives. Investment cost and operating data have been obtained from various suppliers and through contact with technical personnel. The cost of other measures required to get the chillers ready for operation is calculated based on product data, references to other projects, and own estimates. In the comparison it has been assumed that the electrical installations, construction of heat and cooling tubes to an existing machine house were the only thing that was needed to make the chillers operational. District heating, raw water and electricity etc. were assumed to already be connected to the building.    The solution proven to be most cost-effective was free cooling, flowing water from boreholes and cooling against boreholes where geothermal compressors are already in use for heating. This is because of the installation and operational costs being very low. The different heat-driven chillers that have been examined are primarily absorption chillers and desiccant cooling systems, which are mostly effected by the fuel prices during the period of operation, operation load and the chilling power requirement. Big comfort cooling customers are profitable at the self-cost of district heat produced by waste from about 600 kW cooling load. These customers have their highest cooling load when the district heat is at its lowest price during the summer. The desiccant cooling systems could be interesting throughout its entire power range but only when taking in to consideration the air treatment function that is provided. From the customers perspective a moving electricity and district heat price makes the heat driven alternatives less interesting in favor of air cooled compressor chillers. Air Compressor chillers offer more flexibility and are only less interesting when the possibility of free cooling or use of existing geothermal facilities for cooling exists, or when Umea Energi is the producer of cooling at self-cost. If the cooling load is great and bigger land areas are available snow cooling could be an interesting option. The experience of snow cooling is today limited because of few facilities of this kind have ever been built in Sweden. This report aims to give an indication of which cooling technique that is of interest for decentralized cooling from the perspective of Umea Energi and the customer. / <p>Examensarbetet utfördes för A o värme, Umeå Energi AB</p><p>Handledare vid företaget: Johan Brändström</p><p>Johan.Brandstrom@umeaenergi.se</p>

Diss. Stockholm : Tekn. högsk, 2005.

Cooling down the indoor air can be done in several ways. One way is desiccantcooling which will be used at the Stockholm Arena. This method is used in airhandling units that use temperature changes and moisture fluctuations in the air. Oneof the steps is to add heat during the cooling process in order to reduce the relativehumidity of the exhaust air. The air passes thru an adsorptions rotor which thenabsorbs moisture from the supply air. This results in the closing stages that the supplyair temperature drops when hydrating and the result is a cooler indoor temperaturethan the outdoor. This report is a result of a diploma work in building construction at UppsalaUniversity and is written as a guide for the Stockholm Arena to reduce theconsumption of purchased thermal energy, with the aim of producing its own energy.This is reported from a technical perspective, focusing at the design of a propersystem. Heat energy is today planned to be brought from district heating. It couldthou be replaced by other alternatives such as solar panels. To determine this, itinvestigates whether and to what degree solar panels can replace the district heat atthe cooling process of the indoor air from a technical perspective. This has beenimplemented with literature studies and interviews and further on calculations ofenergy but also financially by the annuity method. The case is focused on the summer conditions when the sorptive refrigeration willbe used. According to that calculations and assumptions have been made for probableenergy consumption and production. There after the investment costs weredetermined. The results gave that flat glazed solar collectors had a lower cost based on theenergy production but it required a much larger area than the vacuum solarcollectors. Based on the investment cost, vacuum solar collectors would be lesseconomi-cally significant. Further analysis showed that the solar panels took up almost the same amount ofarea whether of choosing them to stand free or be placed right on the roof. Theinvestigations of the operating temperature of the heating coil gained 60 degreesCelsius to optimize the performance. The size of the storage tank should not exceed3 cubic meters to obtain adequate energy changes. Solar energy is added to the tankat an external heat exchanger. At times when the heat input from the solar panels islower than required the district heat is the most appropriate kind to provide externalheat. This heat is given to the hot water slope leaving the tanks so it won’t disrupt theenergy output from the solar panels. In converted case where the production of heatis greater than required the heat energy can be used for hot water production.

Titel: Sorptionsteknik – Kylteknik.– En studie i kylteknik i kommersiella lokalerSyfte: Syftet med detta arbete är att undersöka och utreda om sorptiv kyla är ettekonomiskt bättre alternativ än fjärrkyla och kylmaskiner i kommersiellalokaler.Metod: Arbetet bygger till största delen på en fallstudie. Både kvalitativa ochkvantitativa metoder har använts. Datainsamlingen har bestått av både primäroch sekundärdata. Informella samtal har förts med tillverkare av olika kylsystemoch med driftpersonal som har hand om driften i byggnaden i fallstudien.Slutsats: Sorptiv kyla är en lönsam, miljövänlig och energieffektiv investering som germervärde för både hyresgäster och fastighetsägare. Det ökar fastighetsvärdet,sänker driftkostnaderna och bidrar till ett behagligt inomhusklimat. / Titel: Desiccant cooling– Refrigeration- A study of refrigeration in commercial buildings.Purpose: The purpose of this study is to investigate and analyze if a desiccant coolingsystem is a better alternative than district cooling or vapor compressorrefrigeration in commercial buildings.Method: This work is based on a case study. Both qualitative and quantitative methodshave been used. The collected data is primary and secondary data. Informalconversations with producers and operators have been conducted.Conclusion: Desiccant cooling is profitable, environmentally friendly and is an efficientenergy investment that gives an additional value for both tenants and propertyowners. It will increase the value of the property, lower operation costs andcontributes to a pleasant indoor environment.

<p>E.ON Värme in Örebro produces electricity and delivers heat and cooling to customers in the region. The Åby Plant operates as a combined heat and power (CHP) plant and runs mostly on different biofuels. A new boiler and turbine is projected for the plant and will start operating fully during year 2012. This creates new possibilities for the existing small scale district cooling production. The number of cooling subscribers is today low and the power output is approximately 7.7 MW but has a great potential of growing in the future. Higher electricity prices, due to the deregulated electricity market and growing environmental concerns motivate the use of district cooling. Cooling production at E.ON Värme in Örebro today comes from modified heat pumps with low efficiency and free cooling. The idea is to replace the heat pumps with either new compression cooling machines, absorption cooling machines (ACM) or a mixture of both. This thesis analyzes possible benefits with the use of heat driven cooling i.e. absorption cooling compared with conventional compression cooling.</p><p>Excess heat from electricity generation in CHP plants is often a problem during the warm period of the year. Normally most of the heat is distributed to industries and households for heating. However, during the summer, the demand for district heating is low which constrain electricity production. The absorption technique utilizes heat as fuel and increases electricity generation during warm periods. This together with a decrease in electricity consumption has positive effects on the environment since it reduces electricity produced in plants controlling margin production. Those plants are most often coal condense plants with high emissions of fossil CO2.</p><p>Most scientists believe that CO2 emissions from human activities are the main cause to the increasing greenhouse effect. The importance of reducing CO2 emissions is therefore high and is one of the motives for district cooling based on ACM that replaces small local electricity driven chillers. Since the Åby plant uses mostly biofuels the contribution of fossil CO2 is low.</p><p>ACM utilizes heat as fuel, therefore the positive effects related to ACM are fairly obvious when the electricity price and the demand for cooling are high. To analyze and optimize the energy system in Örebro, a model was created in the program MODEST, which is software developed at Linköping Institute of Technology. Optimizations with different cooling demands and electricity prices have been made. The cooling production mix is split up in two scenarios, a visionary scenario where no restrictions are considered and a restricted scenario with restricted ACM capacity. The results have been gathered and analyzed and supports the common statements about absorption cooling.</p><p>A simulation of the visionary scenario with unrestricted ACM capacity together with the highest cooling demand (20 MW) and the highest electricity prices (European prices), gave an annual decrease in global CO2 emissions of 9 400 tonnes compared to a scenario with only compression cooling machines. Furthermore, the system running cost was almost 9 MSEK lower on an annual basis. In the restricted scenario, a pay-off analysis shows that the additional costs due to ACM is covered by the lower system cost in less than 3 years when the electricity prices are as forecasted for 2012-2015. All the simulations where absorption cooling was a part of the energy system gave positive results both from an economical and environmental point of view.</p>

E.ON Värme in Örebro produces electricity and delivers heat and cooling to customers in the region. The Åby Plant operates as a combined heat and power (CHP) plant and runs mostly on different biofuels. A new boiler and turbine is projected for the plant and will start operating fully during year 2012. This creates new possibilities for the existing small scale district cooling production. The number of cooling subscribers is today low and the power output is approximately 7.7 MW but has a great potential of growing in the future. Higher electricity prices, due to the deregulated electricity market and growing environmental concerns motivate the use of district cooling. Cooling production at E.ON Värme in Örebro today comes from modified heat pumps with low efficiency and free cooling. The idea is to replace the heat pumps with either new compression cooling machines, absorption cooling machines (ACM) or a mixture of both. This thesis analyzes possible benefits with the use of heat driven cooling i.e. absorption cooling compared with conventional compression cooling. Excess heat from electricity generation in CHP plants is often a problem during the warm period of the year. Normally most of the heat is distributed to industries and households for heating. However, during the summer, the demand for district heating is low which constrain electricity production. The absorption technique utilizes heat as fuel and increases electricity generation during warm periods. This together with a decrease in electricity consumption has positive effects on the environment since it reduces electricity produced in plants controlling margin production. Those plants are most often coal condense plants with high emissions of fossil CO2. Most scientists believe that CO2 emissions from human activities are the main cause to the increasing greenhouse effect. The importance of reducing CO2 emissions is therefore high and is one of the motives for district cooling based on ACM that replaces small local electricity driven chillers. Since the Åby plant uses mostly biofuels the contribution of fossil CO2 is low. ACM utilizes heat as fuel, therefore the positive effects related to ACM are fairly obvious when the electricity price and the demand for cooling are high. To analyze and optimize the energy system in Örebro, a model was created in the program MODEST, which is software developed at Linköping Institute of Technology. Optimizations with different cooling demands and electricity prices have been made. The cooling production mix is split up in two scenarios, a visionary scenario where no restrictions are considered and a restricted scenario with restricted ACM capacity. The results have been gathered and analyzed and supports the common statements about absorption cooling. A simulation of the visionary scenario with unrestricted ACM capacity together with the highest cooling demand (20 MW) and the highest electricity prices (European prices), gave an annual decrease in global CO2 emissions of 9 400 tonnes compared to a scenario with only compression cooling machines. Furthermore, the system running cost was almost 9 MSEK lower on an annual basis. In the restricted scenario, a pay-off analysis shows that the additional costs due to ACM is covered by the lower system cost in less than 3 years when the electricity prices are as forecasted for 2012-2015. All the simulations where absorption cooling was a part of the energy system gave positive results both from an economical and environmental point of view.

Commercial refrigerant industry is one of the biggest contributing factors toglobal warming according to a study by Mota-Babiloni et al. (2015). Studies have shown that emissions of fluorinated greenhouse gases' effect on global warming can increase from 1.3% (2004) to 7.9% (2050) if no change in behaviour is implemented in the industry (Francis et al., 2017). At present, the F-Gas Ordinance sets requirements for leakage warning systems and periodic leakage detection.The most common leak detection systems consist of sensors locatedoutside the cooling process and measure the amount of coolant in the air. However, there are limitations with sensors, including measuring leaks in engine rooms with high air circulation and that the sensors are unable to measure small leaks and mistake other contaminants for refrigerant leakage (Leonardsson, 2021).The purpose of this study is therefore to investigate where leakage occurs in a refrigerant process, howoperating data changes andto propose an alternative detection method for refrigerant leakage.Johnson Control has other technical solutions such as their Performance Index which compares a cooling process operation in practice compared to the theoretical performance that the unit should deliver. In their own test facility, however, it was discovered that a unit can lose up to 20% of its refrigerantmassbefore a clear reduction in COP was discovered(Thorén, 2021).To discover where the leakage in a cooling process occurs, a field study was conducted on a cruise ship docked in Barcelona. The first field study on leak detection was initially carried out by direct method, with the help of an electronic leak detector. The indirect methodwas also used to complement the direct method, this was doneby ocularly looking for oil stains on and around the cooling process. It showed that leakage almost always occurs on the high-pressure side of gaskets, couplingsand plugs. Similar discoveries were made inthe study byFrancis et al. (2017).The results also showed thatthemore connectionsthere are on a unit, such as plugs or service valves, the greater probability that leakage will occur. A solution to reduce leakage on units with many connections,such as supply systems, couldbe to adjustthe design of the systemsand simply remove plugs for connections that are no longer usedfor different reasons.A second field study was conducted on the same cruise ship to determine what operational data changesdue to refrigerant leakage. The unit was emptied into a service tank for two minutes while operating data was logged. After analysis of the results in 16 different operating data points, three of themwere selected for the alternative leak detection model, the DGS-model.Data for longer operating periods, approximately 5 months, with fault-free operation for the selected parameters Θoutin evaporator, expansion valve opening degree and suction   overheating were compared with the operating data from the leakage experiment in field study 2. Thesethree were selected from a total of 14measured operating datapoints. The simultaneous increase ofall three operating data points indicatesrefrigerant leakage. That fact is the major reason for the selection of the three operating data points.Aprobability calculationbased on the three data pointswas created to calculate the probability of thedata points being outside a given range. If the probability calculation says that the chance of the reported value is zero, it is indicated that there is a problem with the process, most likely a refrigerant leak.As a proposal for further work,our proposal is to carry out validation tests of the DGS model on units in operation and a more accurate experiment on refrigerant leakage with operational changes per removed mass.

Kylmaskinerna på Saab ABs fastighet i Järfälla står för en stor del av den totala användningen av elektricitet i fastigheten. Därför är det viktigt att undersöka och analysera hur dessa kylmaskiner presterar i dagsläget och vilka åtgärder som kan vidtas för att förbättra prestandan. Detta examensarbete har fokuserat på hur kylmaskinerna i D-huset på Saab i Järfälla presterar. Därför har flera tester på dessa kylmaskiner utförts. Mätvärdena har huvudsakligen registrerats med ClimaCheck utrustning och uppmätt data har analyserats med datorprogrammen Refprop, Energy Equation Solver och Excel.   Undersökningar av kylmaskinerna i D-huset har visat på flera upptäckter. En upptäckt är att köldmedierna inte har rätt sammanställning. I en del fall beror det på att läckage förändrar ett köldmediums sammansättning och i andra fall har R22 och R417A blandats. De nya kompositionerna har försämrade termofysiska egenskaper än ursprungskompositionen, vilket leder till sämre prestanda av kylmaskinerna. En annan nackdel av läckage av R417A kan leda till höga halter av butan i köldmediekompositionen vilket kan resultera i ett potentiellt brandfarligt köldmedium. Mätningar visar att två kylmaskiner konstant är på och använder i genomsnitt 130kW elektricitetseffekt och producerar 290kW kyla och återvinner maximalt 68kW värme. Den totala energieffektiviteten i hela kylsystemet COPtot är maximalt 1,9 vilket är lågt. Förbättringsåtgärder på kylmaskinerna har vidtagits, bland annat har kondenseringstrycket sänkts till 15barg, detta leder till 24kW minskat kompressoreffektsbehov för samma kylkapacitet, vilket innebär en månadsbesparing på 17MWh. Kylmaskinerna är kopplade till värmesystemet via hetgasväxlare, men dessa är seriekopplade istället för parallellkopplade, detta leder till att mindre energi kan återvinnas till värmesystemet. Ett annat resultat är att ifall kylmaskinernas kondensorer är sammankopplade med värmesystemet kan värmebehovet i D-huset i stort sett elimineras och besparingar på maximalt 251MWh per månad kan uppnås. / The chillers at Saab AB in Järfälla stands for the largest part of electricity usage at Saab’s facilities in Järfälla, it’s therefore important to evaluate and analyze the chillers in order to be able to optimize the performance of the chillers. This master thesis has focused on how the chillers in the D-building at Saab’s facilities at Järfälla perform. Several tests have been done on the chillers in order to do that. The results have been measured by ClimaCheck equipment. The measured data have been analyzed by the computer software Refprop, Energy Equation Solver and Excel. Investigations on the chillers in the D-building have shown several findings. One of the findings is that the refrigerants don’t have the right composition. In some cases it depends on that past leakages changes the composition and in other cases it’s because R22 and R417A have been mixed on purpose. The new compositions have worse thermodynamical properties than the original composition, which have lead to reduction in the chiller’s performance. Another implication caused by leakage of R417A is that it can lead to high concentrations of butane in the refrigerant composition, which can result in a possible flammable refrigerant mixture. Measurements have shown that two chillers are in constant operation they and use an average of 130kW electricity. The chillers constantly produce 290kW cold and the maximum recovered heat is 68kW in total. The total energy-efficiency of the refrigeration system COPtot is 1.9, which is low. Improvements have been done, one of them is that the condenser pressure has been lowered to 15barg, which results in a reduction of electrical power requirement for the compressors by 24kW while the system maintains the same cooling capacity. This results in monthly savings of 17MWh electricity. The chillers are connected to the heating system by desuperheaters, which are connected in series, which results in less energy efficiency. Another result is that if the chillers condensers are connected to the heating system the external heating need of the D-building can almost be eliminated. This would result in savings of maximal 251MWh per month.

In Stockholm, Johanneshov the Slaughterhouse area (Slakthusområdet) can be found. A number of companies have gathered there providing the Stockholmers with meat products. This area has a great need for cooling to supply large cold storages. To facilitate this, a central cooling system has been built, supplying the area with effective and safe cooling. The aim of this master thesis study is to give hints to energy efficient and reliable changes that can be put in place at a low marginal cost depending on the future activities in the area. The suggested changes will be presented to the company Bravida (managing the system), which also desires a deeper understanding of the energy flows through the central cooling system. Firstly visiting the site with proper guidance, we have then tried to understand the function of the system including which machines and media that are used. We have described the present design and come up with suggestions on how to improve the cooling system for a more efficient and safer cooling. Account has been taken to the fact that the whole area will be remodelled radically, thus the improvements must give a short payback time or have a value even after the remodelling. A conclusion drawn from our calculations is that the efficiency of the central cooling is low. The average COP 2(Coefficient of performance in the cooling mode) is around 1,2 which is low. That results in a high electric consumption. Apart from this unnecessarily high water consumption for the cooling tower has been has been observed. We have come up with some ideas to improve the system like:  Enhancing the insulation of the buildings, the pipes and the substation components.  Changing parts in the system like pumps valves and fluids  Introducing a new system for cooling the machines – a bedrock storage so that the heat can be utilized / I stadsdelen Johanneshov finner vi Slakthusområdet, där har ett konglomerat av företag (ca 240 st.) samlats för att förse Stockholm med kött, fläsk och charkprodukter. I detta område finns ett behov av stora kylrum och frysrum. För att underlätta det har man byggt ett centralkylsystem, som levererar effektiv och säker kyla. Syftet med detta examensarbete är att ge förslag på energieffektiva och driftsäkra åtgärder som kan iscensättas med små marginalkostnader beroende på områdets fortsatta verksamhet. Föreslagna driftsåtgärder presenteras för Bravida (driftansvarigt) som också önskar få en fördjupad inblick i centralkylans energiflöden. Genom besök på plats och guidning på området, har vi försökt att förstå hur hela systemet är uppbyggt, vilka aggregat och medier man använder. Vi har beskrivit den nuvarande utformningen och sedan kommit med idéer på vilka åtgärder man kan vidta för en effektivare, säkrare kyl- och frysproduktion. Hänsyn har tagits till att området står inför stora förändringar, så de åtgärder som föreslås är de som kan ge en kort återbetalningstid eller ha ett restvärde efter förändringarna. Metoderna för att komma fram till slutsatser var bl.a. beräkningar utgående från mätdata i bildform som vi fick av fastighetskontoret. Dessa bilder har omvandlats via flera OCR-dataprogram till Excel-filer. Ur dessa Excel-filer har vi sedan kunnat dra vissa slutsatser om energiförbrukningen i Slakthusområdet. Slutsatserna vi drog av dessa beräkningar är att centralkylan har en dålig verkningsgrad. Medelköldfaktorn (COP 2: Coefficient Of Performance) blir bara 1,2 vilket är lågt. Det medför att elenergiförbrukningen blir hög. Dessutom har man en onödig förbrukning av vatten i kylsystemets kyltorn. Vi har kommit med några idéer till förbättringar som:  Isoleringsförbättringar av klimatskal, rör och undercentraler.  Utbyte av delar i systemet som pumpar och ventiler.  Ett nytt avkylningssystem med ett bergvärmelager där den bortkylda värmen används.  Möjligheten att nyttja kyllagring.

Havets Hus i Lysekil bedriver en anläggning med ett flertal havsvattenakvarium som innehåller fiskar och havsdjur från svenska havsvatten. Till anläggningen tas det kontinuerligt in nytt havsvatten från Gullmarsfjorden, till några av akva-rierna kyls det inkommande havsvattnet med hjälp av en kylmaskin. I dagsläget är kylmaskinen luftkyld, vilket är ineffek-tivt. Havets Hus vill undersöka möjligheten att effektivisera kylprocessen genom att kyla maskinen mer effektivt, undersö-ka om det går att ta vara på värmeenergin som annars släpps ut i luften eller på något annat sätt göra kylprocessen mer effektiv.Sex alternativ för effektivare kylning har tagits fram. Det finns två inriktningar på alternativen, antingen att förbättra den befintliga installationen genom att till exempel kyla dess kondensor mer effektivt med hjälp utav havsvatten eller att installera nya maskiner. Det finns också ett kompletteringsalternativ som går att kombinera med alla de andra alternativen och går ut på att installera en värmeväxlare mellan ingående havsvatten som ska kylas och utgående havsvatten från de kylda akvarierna. Alternativet som ger störst ekonomisk sparpotential går ut på att installera två nya kylmaskiner. En som är dimensionerad efter Havets Hus varmvattenbehov och som tar värme från det inkommande havsvattnet och en som fyller upp det resterande kylbehovet. De nya maskinerna fyller det totala kylbehovet på Havets Hus, det vill säga både kylbehovet för det inkommande havsvattnet och för ventilationssystemet. Alternativet kan spara Havets Hus ca 184 000-199 000 kr/år och tillsammans med en värmeväxlare kan det spara ca 202 000-223 000 kr/år.