17 HVAC - Cooling The energy efficiency rating (EER) of an air conditioner is its BTU/h ratingover its Wattage.Example: window air conditionerRating: 10,000-BTU/hPower Consumption: 1,200 wattsEER = 10,000 BTU/h/1,200 watts = 8.3 Btu/WhNormally a higher EER is accompaniedby a higher price.
18 HVAC - Cooling (720 h x .2 kW) x $0.10/kWh = $14.40 Savings Choice between two 10,000-BTU/h units1. EER of 8.3, consumes 1,200 wattsEER of 10, consumes 1000 watts.Price difference is $100.Usage: 4 months a year, 6 hours a day.Electricity Cost: $0.10/kWh.===========================================4 mo. x 30 days/mo. x 6 hr/day = 720 hours(720 h x .2 kW) x $0.10/kWh = $14.40 SavingsSince the EER 10 unit costs $100 more,it will take about seven years for this more expensive unitto break even
23 HVAC -Heating FIRETUBE BOILERS WATERTUBE BOILERS Disadvantages of Firetube Boilers include:Not suitable for high pressure applications 250 psig and aboveLimitation for high capacity steam generationDisadvantages of the Watertube design include:High initial capital costCleaning is more difficult due to the designNo commonality between tubesPhysical size may be an issueFIRETUBE BOILERSWATERTUBE BOILERS