Camus Hydronics DFH/W500 Installation, Operation And Service Manual

Contents

Camus Hydronics DFH/W500 Installation, Operation And Service Manual Manual pdf 23 page image

184.1 FREEZE PROTECTION• Appliance installations are not recommended outdoors inareas where danger of freezing exists unless precautionsare taken. Maintaining a mixture of 50% water and 50%propylene glycol is the preferred method of freezeprotection in hydronic systems. This mixture will protectthe appliance to approximately -35ºF (-37ºC). To maintainthe same temperature rise across the appliance increasethe GPM flow by 15% and the head loss by 20%.The following example demonstrates the procedure to followfor calculating the revised head for the heat exchanger whenusing a water / glycol mixture.• Given that Camus® is showing a heat exchanger flowand head loss of 100 gpm @ 10 feet• Increasing the flow by 15% now results in a head loss of13 feet at 115 gpm (from B&G system syzer). At thisincreased flow Camus® now recommends to increasethe head loss by 20%.• The requirement for the heat exchanger with water /glycol mixture will now be 115 gpm @ 15.6 feet. (ie.1.2 x 13ft. = 15.6 ft.)• A similar procedure must be followed to calculate theadditional head loss in pipe and fittings in order toarrive at the proper pump selection.• For Outdoor installations in colder climates a snow screenshould be installed to prevent snow and ice accumulationon and around the appliance. Regular inspections shouldbe made to ensure that air intake and vent are free ofsnow and ice. Always consider the use of a shelter suchas a garden shed in lieu of direct exposure of theappliance to the elements. The additional protectionafforded by the shelter will help to minimize nuisanceproblems with electrical connections and will allow easierservicing of the appliance under severe weatherconditions.4.2 WARNING REGARDING CHILLED WATER &HEATING COIL SYSTEMSWhen an appliance is connected to an air conditioning systemwhere the same water is used for heating and cooling, thechiller must be piped in parallel with the appliance. Appropriateflow control valves; manual or motorized must be provided toprevent the chilled water from entering the appliance.The appliance piping system of a hot water boiler connected toheating coils located in air handling units where they may beexposed to refrigerated air circulation must be equipped withflow control valves or other automatic means to prevent gravitycirculation of the boiler water during the cooling cycle.Figure 16: Chilled Water System4.3 INLET AND OUTLET CONNECTIONS• All water connections meet American NationalStandard Pipe Threads (NPT).• For ease of service, install unions on inlet and outletof the appliance. The connection to the appliancemarked “Inlet” on the header should be used forreturn from the system. The connection on the headermarked “Outlet” is to be connected to the supply sideof the system.4.4 MINIMUM PIPE SIZE REQUIREMENTSMinimum water pipe connections are as follow forDynaFlame® for single unit installations. The equivalentnumber of straight feet of pipe for each valve and fitting inthe connecting piping must be considered to properlyarrive at the total equivalent feet of straight pipe in the fieldinstalled piping to the appliance. See the pipingrequirements in Part 12 - Installation section of thismanual. Consult factory if longer piping distances arerequired for a specific application.4.5 PRIMARY HEAT EXCHANGERThis appliance uses copper or stainless finned tubing tomaximize the heat transfer process. The copper heatexchanger is comprised of vertical tubes rolled directly intotwo circular bronze headers. The stainless heat exchangeris an all welded construction. It is comprised of two rows ofvertical tubes welded into two circular stainless steelheaders. Both heat exchangers are designed to withstand160 PSIG working pressure. A series of “V” shaped bafflesare installed between the individual tubes to control themovement of the flue products over the finned tubes tomaximize efficiencies.A factory recommended circulating pump ensures properwater flow during burner operation and creates enoughwater turbulence inside the finned tubes and header thatprevents the formation of sediments. Temperature riseand erosion prevention in the primary heat exchanger arecontrolled by the selection of a properly sized circulatingpump. To ensure proper operation and ensure longevity ofthis heat exchanger minimum inlet water temperatures of115ºF (46ºC) MUST BE maintained for non-condensingmodels and 130 ºF (55ºC) for near-condensing andcondensing models.When return water temperatures are below therecommended temperature, the flue products passing overthe copper finned tubes will be cooled below their dewpoint resulting in the formation of corrosive condensationon the copper which shorten its life. Under theseconditions condensation will collect in the base of the innercombustion chamber. Follow the piping recommendationsgiven for low water temperature systems if watertemperatures are expected to be below the recommendedvalue. During initial operation of the appliance in a coldsystem some condensation will be generated but it will bequickly evaporated once the system return temperaturereaches 115ºF (46ºC).