Imperial (US)
Cooling Calculations (Imperial)
Fill in the yellow boxes
Green boxes will auto-populate
Boiler Calculations (Imperial)
Fill in the yellow boxes
Green boxes will auto-populate
Softener Calculations (Imperial)
Fill in the yellow boxes
Green boxes will auto-populate
Dealkalizer Calculations (Imperial)
Fill in the yellow boxes
Green boxes will auto-populate
LSI/Ryznar Calculations (Imperial)
Fill in the yellow boxes
Green boxes will auto-populate
Wastewater Calculations (Imperial)
Fill in the yellow boxes
Green boxes will auto-populate
AWT Calculations Help
Information: Cooling (Imperial)
- Formulas
Tower Tonnage:
RR / 3GPM RR:
Tower Tonnage × 3VOLUME:
1.5 × sump or
5 × RR or
Evap C = RR × 1.83CYCLES (COC):
Tower TDS / MU TDSEVAP (E) gpm:
E = 1% × RR per 10 FMake up (MU) gpm:
(Evap × COC) / (COC - 1)Blow Down (BD) gpm:
E / (COC - 1)Holding Time Index (HTI) Hrs:
0.693(V/BD)CR = 3gpm / ton
E = 3gpm / 100 ton
- Inhibitor lbs/day
((ppm / COC) / 120) × ((MU gpm × 1440) / 1000))
or
(ppm / 120) × (BD(gpm) x 1440) / 1000- Biocide Dosing
slug:
(ppm / 120) × (Volume system / 1000)- Links
Basic Calculations Necessary to Survive in the Field - Part I: Cooling Water
Guidelines for Treatment of Systems Containing Enhanced and Super Enhanced Tubes
Information: Boiler (Imperial)
- Formulas
Boiler Horsepower × 34.5 = # steam / hr
- Inhibitor lbs/day
CYCLES (COC):
Boiler TDS / FW TDS((ppm / COC) / 120) × (MU gpm × 1440 / 1000)
or
(ppm / 120) × (BD(gpm) x 1440) / 1000- Abbreviations
BD: Blow Down
BW: Boiler Water
COC:Cycles of Concentration; Cycles
FW: Feed Water
MU: Make Up
Mmhos: millimhos
ppm: parts-per-million
- End Units
Annual AVG Steam Load:
#/hrCycles of Concentration:
cyclesHours/Day:
hoursDays/Year:
daysCity Water Cost:
$/galMU Conductivity:
MmhosFW Conductivity:
MmhosCondensate Conductivity:
MmhosOperating Hours:
min/yrMU Water Flow:
gpmFW Flow:
gpmBD Rate:
gpmAnnual MU:
galAnnual BD:
galActual % Condensate Return:
%MM pounds per year:
MM lbsCondensate Flow Rate:
gpmSteam Flow:
gpmAnnual Water Costs:
$/yr- Links
Basic Calculations Necessary to Survive in the Field - Part III: Boiler Water
Information: Softener (Imperial)
Exchange Capacity:
30,000 gr/ft3 @ 15 lbs saltPeak Flow Rate:
5 gpm/ft3 resin17.1 ppm total hardness = 1 grain
- Links
Basic Calculations Necessary to Survive in the Field - Part 2: Pretreatment
Information: Dealkalizer (Imperial)
Peak Flow Rate:
3 gpm/ft3 resinExchange Capacity:
10,000 gr/ft3 @ 5 lbs saltExchange Capacity:
13,000 gr/ft3 @ 5 lbs salt w/ NaOH0.25 lbs NaOH per ft3 of resin
Other Anions
-
1ppm PO42-
1.58 ppm as CaCO3
1ppm SO42-
1.04 ppm as CaCO3
1ppm SiO2
0.83 ppm as CaCO3
1ppm NO3
0.81 ppm as CaCO3
1ppm Cl-
1.41 ppm as CaCO3
- Links
Basic Calculations Necessary to Survive in the Field - Part 1: Cooling Water
Information: LSI/Ryznar (Imperial)
A tolerance of -0.3 to +0.3 is the ideal range for swimming pools
A tolerance of -0.5 to +0.5 is acceptable for swimming pools
A Saturation Index of higher than +0.5 indicates carbonate scale formation.
A Saturation Index of lower than -0.5 indicates corrosive water.
Information: Wastewater (Imperial)
- Formulas
Dosage Required = (Volume of Water to be treated x PPM)/1,000,000
Pound Required = (Target ppm/120) x (Volume Water/1000)
Feed Factor = 100/Percent Solution (as percent)
Percent Solution = 100 X (Volume of Polymer/Total Solution Volume) (*Volumes must be in same units)
Percent Removal = ((influent - Effluent)/ Influent) x 100
This is used to calculate the removal efficiency for BOD, TOC, COD, TSS, FOG, etc
Floculant Make down
Day Tank addition Calculation
Floculant Volume Added = (Desired Flocculent Make Down Percent/100) x Day Tank Volume x unit desired conversion
© 2025 Association of Water Technologies
1300 Piccard Drive, Suite LL 14
Rockville, MD 20850
Phone: (301) 740-1421
Fax: (301) 990-9771
