<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1390-6542</journal-id>
<journal-title><![CDATA[Enfoque UTE]]></journal-title>
<abbrev-journal-title><![CDATA[Enfoque UTE]]></abbrev-journal-title>
<issn>1390-6542</issn>
<publisher>
<publisher-name><![CDATA[Universidad UTE]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1390-65422020000200029</article-id>
<article-id pub-id-type="doi">10.29019/enfoque.v11n2.565</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Revisión del estado del arte de sistemas DX-SAHP para la obtención de agua caliente sanitaria]]></article-title>
<article-title xml:lang="en"><![CDATA[Review of the state of art of DX-SAHP systems to obtain domestic hot water]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Quitiaquez]]></surname>
<given-names><![CDATA[William]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Simbaña]]></surname>
<given-names><![CDATA[Isaac]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Isaza-Roldán]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Quitiaquez]]></surname>
<given-names><![CDATA[Patricio]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Nieto-Londoño]]></surname>
<given-names><![CDATA[César]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Toapanta-Ramos]]></surname>
<given-names><![CDATA[Fernando]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Politécnica Salesiana  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Ecuador</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad Politécnica Salesiana  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Ecuador</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Universidad Pontificia Bolivariana, Medellín-Colombia  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="Af4">
<institution><![CDATA[,Universidad Politécnica Salesiana  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Ecuador</country>
</aff>
<aff id="Af5">
<institution><![CDATA[,Universidad Pontificia Bolivariana, Medellín-Colombia  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="Af6">
<institution><![CDATA[,Universidad Politécnica Salesiana  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Ecuador</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2020</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2020</year>
</pub-date>
<volume>11</volume>
<numero>2</numero>
<fpage>29</fpage>
<lpage>46</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.senescyt.gob.ec/scielo.php?script=sci_arttext&amp;pid=S1390-65422020000200029&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.senescyt.gob.ec/scielo.php?script=sci_abstract&amp;pid=S1390-65422020000200029&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.senescyt.gob.ec/scielo.php?script=sci_pdf&amp;pid=S1390-65422020000200029&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen El objetivo del presente artículo es revisar de forma detallada las distintas investigaciones realizadas con sistemas de bombas de calor de expansión directa asistidas por energía solar (DX-SAHP) utilizadas para el calentamiento de agua en los últimos años. El creciente consumo energético, el uso de refrigerantes que debilitan la capa de ozono, la emisión de gases de efecto invernadero a la atmósfera y los efectos en el calentamiento global, son los principales problemas que presentan los sistemas convencionales de calentamiento de agua. El uso de hidrocarburos como refrigerantes representa una reducción en la contaminación, además de ser una de las mejores opciones para reemplazar a los clorofluorocarbonos e hidroclorofluorocarbonos por sus valores de potencial de calentamiento global y potencial de destrucción de la capa de ozono cercanos a 0. Un sistema DX-SAHP aprovecha la energía solar térmica directamente, empleando un colector solar de placa plana sin cubierta. Esos sistemas proporcionan agua caliente sanitaria a más de 50 °C, calentando volúmenes de agua de hasta 200 litros, alcanzando valores de COP superiores a 4. La energía solar y el uso de refrigerantes alternativos de bajo impacto ambiental son propuestos para alcanzar este propósito.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract The investigation purpose is to elaborate a detailed review about previous published investigations with direct-expansion solar-assisted heat pumps (DX-SAHP) used for water heating, in the last years. The growing energy consumption, the using of refrigerants that weaken the ozone layer, the greenhouse gases emission to the atmosphere and the global warming effect are the main problems that the conventional water heating systems present. Using hydrocarbons as refrigerants represents a pollution reduction and it is also the best option to replace hydrochlorofluorocarbons and chlorofluorocarbons, due to their low values of global warming potential and ozone depletion potential, close to 0. A DX-SAHP system takes advantage of the thermal solar energy directly by using a bare flat-plate solar collector. These systems provide domestic hot water over 50 °C and heating water volumes until 200 liters reaching COP values higher than 4. Solar energy and the using of alternative refrigerants with a low environmental impact are proposed to reach this purpose.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[bombas de calor]]></kwd>
<kwd lng="es"><![CDATA[refrigerantes alternativos]]></kwd>
<kwd lng="es"><![CDATA[energía solar]]></kwd>
<kwd lng="es"><![CDATA[DX-SAHP]]></kwd>
<kwd lng="es"><![CDATA[colector solar]]></kwd>
<kwd lng="en"><![CDATA[Heat pumps]]></kwd>
<kwd lng="en"><![CDATA[alternative refrigerants]]></kwd>
<kwd lng="en"><![CDATA[solar energy]]></kwd>
<kwd lng="en"><![CDATA[DX-SAHP]]></kwd>
<kwd lng="en"><![CDATA[solar collector]]></kwd>
</kwd-group>
</article-meta>
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