Hot water is widely used in a variety of industries including: food processing, concrete production, hotel/motel, laundry and many others. Businesses that require hot water in large amounts have to look at specialized heavy duty equipment to make large quantities of hot water for sustained periods. For a very long time, the go to solution was the use of a boiler system, but new technologies over the past 30 years have changed the methods and efficiencies associated with heating water and now recirculating water heaters and direct contact water heaters (also called on demand water heaters) are becoming industry standard.Water boilers were commonplace during the early and mid 1900’s providing heat and hot water to industry and residential buildings in mass. As heating methods developed and forced air systems and central cooling became commonplace, the expense of a water boiler didn’t make much sense for many business and residential buildings. As most of us know, the common residential water heater was developed and boilers become a specialty machine for industrial hot water applications and other specialty operations. The other major negative factor impacting boiler use besides the upfront cost was the training and inspections necessary to operate the equipment. In some cases specially trained employees are required to be on staff to operate a hot water boiler.Eventually the industrial recirculating hot water heater was developed for businesses like concrete plants, bakeries, and other consumers of large amounts of hot water. Industrial recirculating water heaters typically work with a large water holding tank. The cold water is heated and deposited into the tank. The hot water in the holding tank is also circulated back through the heater to maintain and raise the water temperature as desired. These systems are usually very affordable and reasonably easy to install. They will often require a large footprint because of the water holding tank necessary, and they are more expensive to operate on a daily basis than more efficient on demand water heaters. As technology improved manufacturers of recirculating type industrial water heating equipment began offering more efficient versions and retrofitting old versions to improve efficiency by trapping and reusing lost heat.Now, the most popular industrial water heating equipment is the high efficiency and on demand water heaters. They are generally more expensive than recirculating systems but less expensive than boilers. As with recirculation water heaters there is no special license or training required to operate these industrial systems. They are highly efficient in their operation making their annual cost to operate less than boilers or other types of systems. It should be noted that while these water heaters only require a small water holding tank, many of the manufacturers (not all) use very tall designs and the systems may not fit in a standard room. Also, these types are systems are more susceptible to weather and should be installed indoors in most cases.It is safe to say that no matter what style of industrial water heating you choose the efficiency is much better than 20 years ago, but there are still significant differences between cost to purchase, cost to operate and overall efficiencies between the different types of systems. Most customers find a balance between upfront cost and cost to operate and make their decisions based on cash on hand and overall use.