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Steam/Water Heater0 pages
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| Flo-Rite-Temp Instantaneous Steam/Water Heater | ||||||
| Steam/Water Heaters Steam/water heaters are typically classified as instantaneous, semi-instantaneous and tank-type. Temperature control can be defined as either feed-forward or feedback. Feedback systems are error-driven and rely upon an outlet or downstream thermostatic temperature-sensing device to detect a temperature change requirement and then modulate the steam to effect the heat exchange in an attempt to recover the heater set-point. Feedback systems are reactive, and a significant concern is their speed of response to system and application temperature control requirements. Tank-Type Steam/Water Heaters (feedback) Tank-type steam/water heaters typically include a temperature sensing element or coil immersed in a storage vessel with a separate, remote steam control valve. As a function of their integral and often significant storage capability, the poor response times often associated with the relationship of temperature-sensing device and steam control valve are less of an issue. Tank-Type Steam/Water Heaters are a less attractive option because: ٕ They consume a large amount of valuable mechanical-room real estate. They have been identified as amplification and colonizaխtion points for Legionella bacteria. They have significant leak potential over time. Օ Tank repair is difficult, and tank replacement often requires mechanical room/building structural modifications. They consume energy to heat and maintain what is effectively a reserve hot water supply. Օ They require separate steam control valves, which require ongoing maintenance. They require thermostatic element/sensors,which have shown a tendency to wear and eventually rupture under a heavy cycle load. Օ They are slow to recover and may run out of hot water during peak load periods. Tankless Instantaneous Steam/Water Heaters (feedback) Tankless instantaneous steam/water heaters, often referred to as shell and tube heat exchangers, do not include hot water storage capacity. These models will rely upon either an outlet or downstream temperature-sensing element with a separate steam control valve. | ||||||
| Tankless Instantaneous Steam/Water Heaters are a less attractive option because: Lag time from message (thermostat) to action (control valve) creates thermal lag and a resulting temperature swing. Օ Modulating steam supply can cause condensate evacuation issues, resulting in damage from water hammer and tube bundle corrosion. ͕ A cycling phenomenon during low- or no-demand periods will cause premature wear to the thermostatic element. Thermostats typically fail in an open position, making overheated, scald-temperature water available to the system. | ||||||
| High-maintenance feedback systems with large storage tank may leak, corrode or rupture a thermostatic control. | ||||||
| Feedback Instantaneous systems may suffer from lag time, tube bundle corrosion and problems with thermostatic element deterioration. | ||||||
| Armstrong Hot Water Group, 221 Armstrong Blvd., Three Rivers, MI 49093 - USA Phone: (269) 279-3602 Fax: (269) 279-3130 www.armstronginternational.com | ||||||
