| SHCS Calculator SHCS Calculator | | | |
| Please fill in ALL the placeholder numbers (in Bold) and read the result (in the BLUE Italized CELLS) | | |
| First calculate | volume of air in the greenhouse - fill in the figures in the Greenhouse Dimensions Yellow section | | |
| Then fill in the fan, tubing & cost 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 should be: 5 air exchanges per hour and 2-4 feet per sec air speed in the air circulation tubing | | |
| Your important Calculated figures are in cells this color | | | |
| | | | | | | | | |
| DIRECT YOUR QUESTIONS TO THE SHCS FORUM | | |
| | | | | | | | | |
| 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 | 4 | 100 | 20 | 8000 | Main | | | | |
| Section2 | | | | | Section2 | | | | |
| Section3 | | | | =b9*c9*d9 0 | Section3 | | | | |
| Total Square footage | 2000 | Design should be 1.33 feet of tubing per square foot | 2660 | | 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) | 8551.2 |
| Total GH Air Volume | 16551.2 | | Total Box Section CUFT | 8000 | | | | Total Hoop Section CU/FT | 8551.2 |
| | | | | | | | | |
| STEP TWO Fans | NB: From the calculated CFM, choose the CFM for the fan you have in mind and enter it (for 0.02" back pressure if you that figure from the manufacturer's data sheet) | | |
| Number of Fans | Exchange Rate TIMES/HOUR Design | Fan CFM Calculated | Fan CFM from Manufacturer List | Exchange Rate TIMES/HOUR Calculated | | | | | |
| 2 | 5 | 689.6333333333333 | 500 | 3.6251147953018514 | | | | | |
| | | | | | | | | |
| Underground Air Circulation Tubing Underground Air Circulation Tubing | | | | | | 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 | 2970 | 4.026106786191712 | 13.660839843749999 | |
| 2 | 4 | 3.75 | 55 | 27 | 4.1396484375 | | | | |
| | | | | | | | | |
| Cost of system hardware | | | | | | | | |
| Tubing @ $0.30 per foot | Fans, Plenums, @ approx, $200 per Plenum | Controls Package | Total Hardware Costs | | | | | | |
$840.00 $891.00 | $400.00 $400.00 | 100 $100.00 | 1340 $1,391.00 | | | | | | |
| | | | | | | | | |
| Payback Calculations | | | | | | | | | |
| Mass of heatsink in pounds | 480000 | Heat stored with a 1 F deg rise in heat sink temp | 480000 | Your Therm cost ($ per 100,000 BTU's) go herefor rates | 1.55 $1.55 | Stored heat value as natural gas cost per 1 F deg rise | $7.07 $7.44 | Expected # of days you get a 1 F deg Rise | 150 |
| Gas Value gained each year | 636.12 $1,116.00 | Your Electricity Cost in $/kilowatt hour (rates here) | 0.08 $0.08 | Operating cost - fans @ 2 amps for 8 hrs/day | $53.73 $53.73 | Yearly Net | 367.47999999999996 $1,062.27 | Hardware Payback in Years | 1.3094574647547899 |
| | |
| | | | | | | | | |
| | | | | | | | | |
