Figure 10
Figure 11
• The first piece delivers 11000 Btus or 1.10 gpm that needs a ½ ” pipe .
• The second piece delivers 9600 Btus or 0.96 gpm that needs a ½ ” pipe .
• The third delivers 14400 Btus or 1.44 gpm that needs a ½ ” pipe .
• The fourth delivers 4800 Btus or 0.48 gpm that needs a ½ ” pipe .
• The fifth delivers 2400 Btus or 0.24 gpm that needs a ½ ” pipe .
If you add all of these up , you will have a total Btu load of 42,200 or 4.22 gpm that means your main will be a ¾ ” pipe . Many of us will also use a ⅜ ” piece of tubing that will do the fourth and fifth nicely and severely reduce your installation costs too !
Remember , your baseboard output of 550 Btus per foot based on a 175 ° F water temperature ? Then you have the following baseboard requirements . The first room has 20 feet of baseboard , the second has 18 feet of baseboard , and the third has 26 feet of baseboard . The fourth room has 8 feet of baseboard , and the last one has 4 feet of baseboard .
To size our circulator , we know we need to know the gpm , which we know is 4.22 gpm , and the feet of head . Just as an example , let ’ s say it ’ s based on 70 feet of run . 70 ’ x . 06 = 4.2 feet of head So , we need a circulator that will pump 4.2 gpm at 4.2 feet of head . Using Figure 12 , you could use that circulator and set it to low-speed . Using Figure 13 , you would have a choice between the model ‘ D ’ or the model ‘ E ’, so which one is cheaper ? Okay , one more and I ’ m going to double everything again .
Figure 12
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