Heaters Buyer's Guide FarmTech – 2012 http://www.farmtek.com Whether you own a home, greenhouse, barn, workshop or warehouse, you will need to efficiently heat the space. Knowing the different types of heating systems available and the best type for your needs will help you make an informed decision for your specific application. What are the different types of heat? In order to understand common heating systems, it is important to know the difference between the three types of heat, which are conduction, convection and radiant. Conduction is the transfer of thermal energy from one object directly to another by contact. Touching a hot or cold object is an example of conduction. Convection is the transfer of thermal energy from one object to another by heating the air between the two. An example of convection heating is heating the air inside a building, thereby raising the temperature of the objects within the space. Radiant (infrared) heating is the transfer of heat from a high-temperature object to a low-temperature object. The air in between the objects is not heated; radiant heat only heats the objects it comes in contact with. An example of this would be the sun-warming the Earth. Convection Heating Radiant (infrared) Heating Radiant (infrared) Heating What are the different types of heaters and which one is best for my application? When choosing which type of heater is best for you, it is important to consider which applications each heater is ideal for. FarmTek offers in-floor heating systems, spot, tube, forced-air and electric heaters, each with advantages for different situations. Radiant in-floor heating systems: Radiant heating works the same way the sun does it heats the object, which heats the air surrounding it. Radiant under-floor heating is one of the most efficient and least expensive methods of heating a building. Radiant Floor Heating TekCoil & TekFoil Boilers Boiler Panels These systems contain pex tubing which is installed under flooring or concrete slabs. Hot water flows through the tubing, heating the floor above it and radiating heat from the ground upwards. This makes it more efficient since the heat emanates from the floor instead of rising to the ceiling. Contact us and we can help you design your custom in-floor hydronic heating system. There are many benefits of radiant heat. It is often more efficient than baseboard heating and forced-air heating because no heat is lost while moving through ducts. This type of heating is also very clean because there is no moving air which decreases the amount of dust allergens traveling through the space. Hydronic in-floor systems also use very little electricity, which lowers energy costs for users. Radiant Spot Heaters: This type of radiant heater is located in a specific area to heat an exact spot, instead of the entire vicinity. An example of this is using an infrared heater above large warehouse doors. The heaters will warm the objects under them, not the air, reducing heat loss through doorways and loading areas. A spot heater we offer is the electric Quartz Infrared Heater which is ideal for work stations, lobby entrances and indoor plants. The benefit of radiant spot heating is that it heats just the objects it is located above, not the air around them. When radiant heat is used, people, machinery, objects and floors all become heat reservoirs, leading to better fuel efficiency and greater cost savings. Infrared tube heaters: These can be used for complete building heat or spot heating. The best applications for these heaters are in large warehouses where there is significant heat loss from doors frequently opening and closing, and in buildings with ceiling heights above 10 feet. We offer the SunStar Infrared U-Tube and Straight-Tube Heaters which provide uniform radiant energy distribution. These heaters are designed to meet any commercial or industrial heating need, and are extremely efficient, resulting in energy savings as high as 70% in large buildings and up to 50% when compared to forced-air convection heating. Radiant Spot Heaters Infrared Tube Heaters Force-air Heaters Electric Heaters Forced-air: These are one of the most commonly used types in North America. When on a thermostat, the system works by igniting a burner within the heater's combustion chamber when the space's temperature drops below a preset level. The heat that is created transfers to the furnace's heat exchanger, and is then moved throughout the space by a system of ducts. Forced-air heating heats by convection. These heaters work best in animal housing, sports arenas, commercial greenhouses, warehouses, manufacturing facilities and shops. We offer the Modine Effinity 93 Condensing Unit Heater, which is 93% efficient, making it one of the most energy-efficient heaters available. Another popular forced-air heater is our Modine Hot Dawg Heater, which is ideal for smaller areas like your garage or workshop. Forced-air heaters are excellent when used with programmable thermostats since the system takes a short time to recover. Forced-air heaters provide uniform heat for strong and rapid plant growth, frost protection and frost control. These heaters have a very attractive return on investment. Electric utility heaters: These heaters force an electric current through an element which generates heat. Electric heaters are typically fan-forced, and contain an electric fan to pass air over the heating element. Other electric heaters are convection heaters in which the heating element exchanges heat with the air next to it, warming up the room. These work best in small spaces such as garages, shops, hobby greenhouses, sheds and workshops, office spaces, and for on-the-job applications, like drywall, painting and floor refinishing. We carry several different electric utility heaters including the Heat Wave Salamander Heater and a heavy-duty portable model that is ideal for your home, garage or work area. The advantage of electric utility heaters is that they are very portable and useful in small areas. They also don't require venting, and are safe and easy to use. How do I determine where to place a heater? The positioning of a heater depends on variables like clearance to combustibles, location of exhaust venting, the height or width of the space and where the heat is going to be directed. The placement of entry and garage doors must also be taken into consideration. If you are unsure, discuss these parameters with a professional before positioning a heater in your space. Mounting hardware may be necessary for your application, so ask your National Account Manager to help you decide what is appropriate for your needs. What needs to be considered in high altitudes? Precautions must be taken when a heater is being used in altitudes 2,000 ft. above sea level or higher, since high altitudes alter atmospheric pressure and oxygen content. In order to keep a fire burning in the burn chamber of the heater, the correct fuel-to-oxygen ratio must be maintained. The heater's fuel and air travel through an orifice into the combustion chamber, and must maintain the correct mixture to ignite. In high altitudes, an adjustment to the orifice is required to compensate for this change. If you live in a high-altitude region, mention this to your National Account Manager to determine if a high-altitude kit is needed, and to size your heater correctly. How do I determine the number of BTUs needed to heat my space? A BTU (British Thermal Unit) is the approximate amount of energy needed to heat one pound of water one degree Fahrenheit. Here is a simple formula that is commonly used to determine the BTUs per hour needed to heat a space in an insulated building: Cubic feet to be heated* x 0.133 x Desired temperature rise** = BTUs needed per hour *Cubic feet to be heated* x 0.133 x Desired temperature rise** = BTUs needed per hour ** Subtract the lowest expected outside temperature from the desired inside temperature. If you are trying to determine the number of BTUs needed to heat an un-insulated space, a different formula is used. Call your National Account Manager for help with this calculation. What are heater ratings? All heaters are given a BTU and forced-air heaters are given a CFM (cubic feet per minute) rating. These ratings tell the user how many BTUs the unit can produce in one hour, and how many cubic feet of air per minute the unit's fan needs to push the heat outwards. A rule of thumb is the higher the BTU rating, the higher the CFM rating. What if I need to heat a high-humidity area? None of our stock heaters are recommended for a high humidity area due to metal heat exchangers and elements that can corrode easily. However, many heater manufacturers such as Modine substitute stainless steel elements for use in areas of high humidity. Ask your National Account Manager for more details if you are planning on using a heater in a high humidity area. What accessories would be useful to purchase with heaters? Ceiling Fans: Use of a ceiling fan will help you get the most out of your HVAC systems. Remember that heat rises, and the air in your space will have varying temperatures as it ascends, with the warmest air closest to the ceiling. Choose a fan with a reversible motor to reap the benefits of both warming and cooling functions. In the winter, run your fan in a clockwise direction to push the warm air downwards. In the summer, run your ceiling fan counter-clockwise to circulate the room's air and provide a cooling breeze.