Characteristics of water - EMS

1 Characteristics of waterBoiling point 212F @ sea level, higher altitudes?Freezing point-32 FSpecific heat Ammonia has highestice and steam SH = .5 Specific weight heat of fusion 144 heat of vaporization 970 7 neutral (less is acid more is base)Mpemba (IM PEM BAH)effectAltitude affects boiling pointAltitude (ft)Altitude (m)Pressure (mm-Hg)Temp. FTemp. weight of water = weight of oils = . (oF)Density- -(slugs/ft3)Specific Weight- -(lb/ft3)(lb/gallon) heatSpecific heat of water = 1 Material(cal/g C)(J/kg K)(cal/g)(J/kg) s required to heat waterIt takes 1 BTU to heat 1 pound of water 1 degree FBTU s = pounds X temp. heat of fusionPounds x 144 BTU sLatent heat of vaporizationPounds x 970 BTU sHeat 200 pounds of ice @ 20F tosteam @ factorPure water = 7 (neutral)Above 7 alkaline, tends to scaleBelow 6 acidic, tends to corrodeMaintaining temperature below 160 Ftends to inhibit scaling in an opensystem. A close system generally willnot scale at higher effectDiscovered in 1969 by student in Tanzania, AfricaHot water freezes before cold waterWHY?

2 1. Good conduction no frost2. Convection currents more active and reducedinsulating Evaporative effect4. Warm water has less gaseous impuritiesGAMAGas Appliance Manufacturers costStep s =Lbs X TDStep 2 Fuel =BTU sBTU per unit X EFBTU s per unitOil-144,000 per gallonNatural gas 100,000 perthermor 100 cubic feetLP gas 94,000 per gallonElectric 3413 per KWWater mixing formulasWhat will temperature be if 60 gals @ 120 degrees are mixedwith 30 gals @ 60 degreeTemp = (Q1 X Temp1) + (Q2 x Temp2)/ (Temp2 + Temp1)= (60 X 120F) + (30 X 60F) / (120F + 60F)= (7200 + 1800) / 180= 9000/180= mixing formula 2If the cold water is 60F and there is 40 gals of 140F wateravailable, how many gals can be produced @ 95FQ1 =Q2 x TD tankTD desired=40 gals. X (140F-60F)95F 60F=40 gals. X 80F35F=320035= gallonsWhat happens when we lower the temperature to 120F?Recovery RateBurner capacity X x temp. riseRecovery RateA 40,000 BTUH WH, 80% efficient, is capableof supplying _____ gallons per hour atan 80F temperature ,000 BTUH x.

3 80 = 32,000 amount BTU s needed to raiseone gallon X 80 = rate =32, 48 gals per hourFirst hour ratingFirst hour rating = recovery rate + tank capacity= 48 gals. + 40 gal. tank= 88 of GPM on temp riseTemp. Rise =BTUH (output)GPM X 500500 = X 60 metric to imperialGallons = = gallons X Fahrenheit to Celsiusand VSF = (9/5 X C) + 32C = 5/9 X (F 32)9 40 30 Calculating volumeVolume of square or rectangularshaped building = area X height,orlength XVolume = length X width x height= 30 X 40 X 9 = 10,800 cubic feetVolume of a triangular building= area of triangle X lengthorheight50 6 24 Step 1. Area of triangle =length X height2=24 X 6 2= 72 sq. Volume of triangle = area X length= 72 sq. ft. X 50 = 3600 cubic feetVolume of a cylinder= Area of circle X length of cylinder10 30 Step of circle = XRadius2or R2= X (5 X 5 )= X 25 square feet= square feetStep 2. Volume of cylinder = area of circle X length of cylinder= square feet X 30 = 2355 cubic feetGallons = cubic feet / = cubic feet X gallons X a water heaterConventional Storage water HeatersDemand (Tanklessor Instantaneous) WaterHeatersHeat Pump water HeatersSolar water HeatersTanklessCoil and Indirect water HeatersConventional Storage water HeatersDemand (Tanklessor Instantaneous)

4 water HeatersHeat Pump water HeatersSolar water HeatersTanklessCoil and Indirect water HeatersMetlundorChilipeppersystemHeat trapsFVIRF lammable vapor ignition resistance A device to prevent ignited vapors frompassing out of the combustion chamber A one way intake system to control themovement of makeup air into thecombustion chamber An inner door and burner assembly tocreate a sealed junction with thecombustion chamber, preventingcombustion air and flammable vaporsfrom entering the chamber through thefront of the water heaterFVIR-TroubleshootingFlammable vapor ignition installation environment may be conditions exceed the TCO switchcutoff exceed 115 water heater may be starved for combustionair. Don t forget an electric dryer, it also consumes may not be a draft at the water heater A flammable vapor incident has Plumbing Code Chapter 5 Section 501- water heater must be set at 120F. If thewater heater is used for space heating it may be set above120F. If the temperature is above 140F amastertempering valve must be installed.

5 (ASSE 1017).Customer may set temperature above 120F but no oneelse maySection heatersource of ignitionmust be 18 abovegarage floor. Both fossil fuel and : FVIR appliancesMechanical Code Section heaters used for space heating must beapproved for such : When replacing a water heater used forheating be sure to replace with same pipe sizingNatural gasLP gasVenting single applianceHow house pressurization affectsgas flameTax credits for solar WHFederal-30% until 2016 no limitNorth Carolina 35%-$1400 limitSolar water heatingSolar constant = BTU s per sq. 300 Btuh per sq. ft. reach the earthThree types of solar energy to be collectedDirect 300 Btu/sq. 50 Btu/sq. 60 Btu/sq. KWH/sq. meter/ yearCollector orientationFace TRUE south (15 degree variation)Tilt angle = degree latitude- water heating onlyDegree latitude plus 15 degrees-space heating(10 degree variation acceptable)Flat plate collectorGlazing selectionHigh shortwavetransmittnace(.2 micrometers)Lowlongwave transmitance(greater than )Low absorbance at allwavelenghtsExcellentweatherabiltySing levsDouble GlazingForwater heating onlysingle glazing is all that sneeded in our of lowinsolationwould benefit with doubleglazingAbsorber PlateBlack Paint97%absorbtion97%emisstivitySelectiv e Surface95%absorbtion9-12%emisstivityvsCo llector sizing20 square feet per person for first two8 square feet each person thereafter (sun belt)12-14 square foot per person(north)Corrosion ControlPrevent direct connection of anodic andcathodicmetals or supply sacrificial end (anodic)MagnesiumZincAluminumCarbon steelBrassTinCopperBronzeStainless steelProtected end(cathodic)

6 Storage tank gallons per square foot collector gallons per square foot in very sunny areasThese rules of thumb will prevent overheatingTransfer FluidsWater+ cheap, high heat content, safe freezes,suportsgalvanic corrosion, boils at lowtemperature, promotes scale formationWater/Glycol+ will not freeze above 35F, can handle corrosioninhibitors-Must be replaced regularly, not stable at hightemperatures, boils slightly above waterHydrocarbons+Low cost, no freezing problems, nontoxic-breakdown at high temperatures (become acidic), thickenwhen cold causing pump Fluids+do not freeze, do not boil, do not corrode, will last LOS-Initial costControlsPump sizingCollector loopDetermine the head +adjusted friction lossesDetermine the GPMwater-GPM = collector X .015 Silicon-GPM = sq. ft. collector X .039 Storage loopUse manufactures specs