BY GEORGE LANTHIER
Looking at Figure 6 and Figure 7 you can see that there is only one circulator for the entire system or a zone since the flow is directed through the radiation by the on-pipe fittings , Figure 8 and Figure 9 . With a single circulator it would have to be large enough to pump all of the gpms through the entire foot of head of the system . By zoning , the pumps get smaller because now they only have to pump the gpm of the zone and the length of the longest zone . With
P-S systems the pump only has to pump the Primary loop or the Secondary loop , but we need to separate them since water always seeks the path of least resistance . By spacing the tees no more than 12 inches apart , we decouple the Secondary loop ( s ) from the Primary loop ( s ).
Figure 6
Figure 7
Figure 8 Figure 9 westmor-ind . com
Let ’ s take another look at the diverter system as an introduction to building a Primary-Secondary system . The most important part of any system is proper pipe sizing that will carry the Btus required to heat the loads . In Figure 10 we can see that by properly sizing our piping , we can in fact control the amount of heat that we want to carry . In a diverter system , the main must be properly sized as well as each branch serving the heat emitters . So , let ’ s go back and look at that simple system in Figure 11 . But for this example , we ’ re going to double all of the Btu numbers and use copper tubing ( pipe ) in all of our examples .
Remember , we have five pieces of radiation installed in five rooms .
36 SEPTEMBER 2023 | FUEL OIL NEWS | www . fueloilnews . com