1. Cost Calculation for Anti-Freeze Usage VS. Weep Water Let’s do some cost comparison for an owner who has a Sub Zero compared to Traditional Weep System with some average statistics. SubZero: We recommend 4 to 8 ounce of antifreeze per purge per bay. Say we use 4 ounces per purge per bay. Assume we have 1 bay. Assume on average we wash 32 cars per day. Also assume that these cars are not washed one after the other immediately, which leads to 32 purges of antifreeze per day in that bay. Each purge uses 4 ounce. So total antifreeze used is 4 x 32 = 128 ounces per day = 1 gallon per day. So now we now that we consume 1 gallon of antifreeze per day. Assume the average cost of antifreeze to be $5/gallon. That means cost to owner for antifreeze is $5/day. For 1 month it will $5 x 30 = $150. So it costs the owner $150 per month in antifreeze. Assume $20 for electric power consumption for Sub Zero. So total cost for operating Sub Zero is $170 per month. Traditional Weep Water System: On average, we need 1/3 GPM of water flowing through port for each bay on the weep water system to prevent it from freezing. Again we assume we have 1 bay. 1/3 gallons per minutes means we will consume 1 gallon of water in 3 minutes OR 20 gallons of water in 60 minutes OR 20 gallons of water in 1 hour. Again consider that we wash 32 cars per day. Let assume that the average length of each wash is 5 minutes. So in a 24 hour day we only stop weeping for 5 x 32 = 160 minutes = 2.66 Hours. So in a particular day on average, we will weep for 24 - 2.66 = 21.34 hours. We use 20 gallons of water in 1 hour, so in 1 day, we will use 20 x 21.34 = 426.8 gallons of water. Let’s round it to 425 gallons per day. This is the amount of fresh water that we use every day. In 1 month we will consume 425 x 30 = 12750 gallons of fresh water. Now, we need to look at the water and sewer rates for our location to calculate how much it will cost us for using this amount of water. Generally, there is a water cost and a sewer cost and an additional surcharge cost which has to be accounted. Sometimes, the borough or municipality charges a fixed cost per EDU. 1 EDU is 1000 gallons of water and sewer (Please check with your water authority). In such cases, the calculations may become easy going forward. Please check with your local borough or municipality to inquire about rates that they charge. For calculations, we will consider the water and sewer rate in central Pennsylvania which is very conservative. On average a typical car wash has a 2” main feed line. For a 2” feed line, the average water and sewer rates including the surcharge is $15.26 per 1000 gallons of water. We calculated ahead that we consume 12750 gallons of water per month. Then on average, a typical one bay car wash will incur, 12.75 x 15.26 = $194.56 of cost for weep water per month. We have not considered the cost of managing the ice buildup due to water weep. We will not consider the maintenance cost or labor cost associated with removal of ice. But if such cost is incurred then it should be added to the total cost for having a weep system in operation. Cost Comparison: So on average, by switching to Sub Zero, a car wash owner saves $194.56 - $150 = $44.56 per month per bay. If we have a 5 bay wash setup at our location, we save $44.56 x 5 = $222.8 per month. A 5 bay Sub Zero costs about $4200.00 Considering 5 months of operation in a year (November, December, January, February, March), we save $1114 per year. ROI or Return On Investment for a 5 bay Wash Setup will be $4200 / $1114 = 3.77 years. So basically, a car wash owner would have recuperated his investment in Sub Zero in about 3 and 3/4 years on average on a 5 bay setup. The above steps can be followed in that order to obtain a personalized cost comparison report for any wash setup. Contact Technical Support at 800-528-5733