Yearly Fuel Utilization Efficiency (AFUE): The Annual Fuel Utilization Efficiency (AFUE) rating shows how well a heater changes over energy into usable heat. The rating is communicated as a level of the yearly yield of heat (yield rating in Btus – warm British units, a proportion of energy) to the annual energy contribution to the heater (input rating in Btus).
Evaluations can be sorted in an accompanying manner:
Low Efficiency: AFUEs under 71%.
Mid-Efficiency: AFUEs somewhere in the range of 71 and 83 percent.
High Efficiency: AFUEs of 90% or more.
Appraisals somewhere between 84 and 89 percent are not regular—acidic condensate, unsafe to the heater, structures at these rates. Public Law No. 100-12, passed in1987, necessitates that all gas heaters produced after January 1, 1992, have a base AFUE of 78%.
Barometric Vent Combustion: If a chimney stack is accessible, heaters with this framework are the most economical to introduce. Barometric vent heaters have AFUEs of 60-65 percent when outfitted with standing pilots and AFUEs of 63-70 percent when furnished with electronic start frameworks. With uncommon vent dampers, environmental vent units can accomplish AFUEs of 78-80 percent.
Gathering (or Recuperative Units): These units are effective for specific plans arriving at AFUEs of up to 97 percent. In contrast to ordinary constrained air heaters, consolidating departments catch most of the water fume and heat contained in hot vent gases that would typically escape up the stack. At that point, the getting away from gases goes during a time heat exchanger, and condensate is ousted. The heat exchangers are made of consumption-safe tempered steel, and many have lifetime guarantees. Exhaust is cooler than that of customary heaters and can be vented with PVC channeling.
Downflow or Counterflow Furnace: These units have a blower at the top to bring air into the heater. Heated air is smothered at the base. This kind of heater is utilized to supply floor channel frameworks.
Electronic Ignition: An electronic start dispenses with the requirement for an energy-squandering standing pilot. Fuel is utilized just when required. The pilot is lighted with an electric sparkle.
Heat Exchanger: The heat exchanger is a metal chamber in the heater that houses a gas burner. The fire delivered by the burner heats the section. When the outside of the room becomes hot, the air encompassing it is warmed and used to heat the house. Further developed plans upgrade effectiveness and give calmer activity.
Flat Flow Furnace: Air voyages evenly from one side of the heater, across the heat exchanger, and hot air extinguishes on the opposite side. This sort of heater is introduced in regions with restricted headroom, for example, storage rooms or unfinished plumbing spaces. They can likewise be introduced underneath floors or suspended beneath roofs.
Non-weatherproof: These units are intended to be introduced inside.
Force Combustion: In this framework, burning is delivered by a blower. The blower pushes the burning gases through the vent and manages the measure of ignition air. Force-burning heaters don’t need a draft hood. This lessens off-cycle misfortunes and further develops proficiency. Many force-burning heaters work at 78-80 percent AFUE. When furnished with an extra heat exchanger, they can work at AFUEs of 90-96 percent.
Heartbeat Combustion: (These models are recorded under consolidating heaters.) Pulse ignition is delivered without anyone else sustained “beats.” This particular framework blends air and fuel in a fixed burning chamber. A flash touches off the combination, and the subsequent expansion in pressure shuts the gas/air gulf valve. The ignition items are constrained through an exhaust pipe and the tension in the burning chamber drops, re-opening the channel valve. The following burning cycle is touched off by the heat staying from the past process. This cycle rehashes the same thing around 60 times each second. Heaters with this ignition framework have AFUEs from 91-97 percent. Exhaust gases, at 100-200 degrees Fahrenheit, are sufficiently cool to vent through PVC funneling.
Fixed Combustion: Sealed burning frameworks attract all the air utilized for ignition from an external perspective, and exhaust gases are immediately vented to the outside. Since cold external air isn’t blended in with the warm indoor air during ignition, productivity is upgraded. Heaters with this sort of burning framework have an AFUE scope of 70-80 percent.
Upflow Furnace: These units have blowers at the base that bring air into the heater. Heated air is smothered at the top. These heaters can be introduced in utility rooms, storerooms, or storm cellars.
Vent Damper: The vent damper is a “flapper” gadget introduced in the pipe. At the point when the heat request has been met, the damper closes, catching lingering heat for flow in the home. When heat is required, the damper opens before the burners are lighted to permit ignition vapor to get away. The damper’s remaining parts open just as long as the burners are on. Burners can’t light if the damper is shut.
Weatherproof: These units are intended to be introduced outside.