| SHCS Calculator SHCS Calculator | | Please fill in ALL the placeholder numbers (in Bold) and read the result (in the BLUE Italized CELLS) | |
| First calculate | the volume of air | in the greenhouse | by filling in the figures | in the | Greenhouse Dimensions | Yellow section | | | |
| Then fill in the fan & tubing data in the green cells | Your Calculated figures are in italics | Data Entry Points are in bold, change any or all. | Don't change the italized formula cells!!! | Ideal Design Numbers (blue cells) should be: | 5 air exchanges per hour | and 2-4 feet per sec air speed | in the air circulation tubing | | |
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| STEP ONE Greenhouse Dimensions STEP ONE Greenhouse Dimensions | | | Enter a zero in cells that do not apply! BTW, a half circle hoop house has an 180 degree included arc |
| Box >>>> Sections>>>>>>> Box >>>> Sections>>>>>>> | Height | Length | Width | Box Section Sub total CUFT Box Section Sub total CUFT | Hoop >>>>> Sections>>>>>> | Arc Included | Radius | Length | Hoop Section Sub Total CUFT |
| Main | 8.5 | 48 | 18 | 7344 | Hoop One | 0 | 0 | 0 | |
| Section2 | 8.5 | 48 | 18 | 7344 | Hoop Two | 0 | 0 | 0 | |
| Section3 | 0 | 0 | 0 | =b9*c9*d9 0 | Hoop Three | 0 | 0 | 0 | |
| Denny - from the calculations, it is clear that you have a massive amount of air volume, much more than a lower house. Because we design for a 5 times per hour air exchange to the underground heat sink, the air handling system is large too. I've tweaked it a bit so that the tubing and fan needs can be minimized. But you will have to add 12-14" ducting to draw air from at least 8 feet high. That way you will be using high temperature air for the heat exchange - that translates into less money for the fans and tubing matrix. With these figures, you are looking at about $1800 for the system hardware (about $1/sqft) at 2 fans per house with 24 tubes in each (8 trenches with 3 tubes in each). I've included Payback calcshere | | Get more precise figures for your Hoop Section Volumes from here.Remember to zero out or clear the contents of calculator cells above if you use that other calculator - use the figure you get in the next cell over (just above the calculated value for "Total Hoop Volume CU/ft" which should be blank before you add the figure from the other calculator) | 4786 |
| Total GH Air Volume | 19474 | | Total Box Section CUFT | 14688 | | | | Total Hoop Section CU/FT | 4786 |
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| STEP TWO Fans | NB: From the calculated CFM, choose the CFM for the fan you have in mind and enter it (use the CFM at 0.02" back pressure if you can get that figure from the manufacturer's spec sheet) | | |
| Number of Fans | Exchange Rate TIMES/HOUR Design | Fan CFM Calculated | Fan CFM from Manufacturer List | Exchange Rate TIMES/HOUR Calculated | | | | | |
| 4 | 5 | 405.7083333333333 | 400 | 4.929649789462874 | | | | | |
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| Underground Air Circulation Tubing Underground Air Circulation Tubing | | | By design, GH should have at least 1.33 feet of tubing for each sq foot of greenhouse ------> | 2298.2400000000002 2298.2400000000002 | Total Feet of Tubing | Tubing Air Speed FT/SEC | Time in each Tube SEC | |
| Plenums | Tubing Diameter | Effective Diameter | Average Length of tubing | # of tubes in each plenum | Total Tubing Effective Area SQFT | 2400 | 3.623496107572541 | 6.8994140625 | |
| 4 | 4 | 3.75 | 25 | 24 | 7.359375 | | | | |
| | | | Total # of Tubes | | | | | |
| | | | 96 | | | | | |
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