<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>lizknope</author><text>This Old House on PBS routinely installs systems over 95%.&lt;p&gt;There are systems here listed at 98.5 AFUE&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.energystar.gov&amp;#x2F;products&amp;#x2F;most_efficient&amp;#x2F;furnaces&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.energystar.gov&amp;#x2F;products&amp;#x2F;most_efficient&amp;#x2F;furnaces&lt;/a&gt;</text><parent_chain><item><author>kwhitefoot</author><text>&amp;gt; Those could be installed everywhere from .. water heaters .. to scavenge some of the 65% of fossil fuel energy that winds up as waste heat.&lt;p&gt;Modern condensing gas boilers for domestic use are better than 90% efficient, the exhaust gas is very cool so I don&amp;#x27;t think that thermoelectric devices have much to offer there.</text></item></parent_chain></comment><story><title>Cheap material converts heat to electricity</title><url>https://www.sciencemag.org/news/2021/08/cheap-material-converts-heat-electricity</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>NohatCoder</author><text>That is because the 90% is heat efficiency, this is for extracting electricity, which is much harder.</text><parent_chain><item><author>kwhitefoot</author><text>&amp;gt; Those could be installed everywhere from .. water heaters .. to scavenge some of the 65% of fossil fuel energy that winds up as waste heat.&lt;p&gt;Modern condensing gas boilers for domestic use are better than 90% efficient, the exhaust gas is very cool so I don&amp;#x27;t think that thermoelectric devices have much to offer there.</text></item></parent_chain></comment><story><title>Cheap material converts heat to electricity</title><url>https://www.sciencemag.org/news/2021/08/cheap-material-converts-heat-electricity</url></story>