Over the past few years, a tremendous number of modulating/condensing (mod/con) boilers have been installed and incentivized throughout our service territory. These qualify as high-efficiency boilers because they have efficiency ratings in the 90s-some as high as 95% to 97% AFUE. These boilers intentionally condense some of the flue products that form as a result of combustion.
As heating contractors, we normally ensure that a standard boiler never condenses its flue products because the condensate would rot out the boiler and vent piping. So what's different? When combustion occurs, energy in the form of heat is transferred through a heat exchanger to flowing water on the other side of the flame. Combustion gases, formed when the flame is produced, contain water in the form of vapor. Generally, these vapor gases vent out of the boiler through the venting/chimney system and out into the atmosphere. But mod/con boilers are designed to allow the flue gases to condense right inside the heat exchanger. They even provide a drain to allow the condensate to escape from the heat exchanger and drip through a neutralization kit into a drain or condensate pump.
When these combustion gases are condensed, the heat energy they contain is saved-this is usually lost up the chimney, essentially just thrown away! In a steam system, when the water vapor in the combustion gases condenses, it gives off a lot of latent heat. How much? For every pound of vapor that condenses back to liquid, 1000 BTUs of latent heat are released. In mod/con boilers, the heat exchanger "catches" this heat and transfers it over to the system water. That's how these mod/con boilers achieve their higher efficiency ratings: more of the unit of fuel goes into heating the system water rather than up the flue pipe.
Like its name suggests, in addition to condensing, the mod/con boiler can also modulate. As the load changes, the boiler will only consume the necessary fuel to meet that load. Unlike traditional on/off boilers where-if they're firing-they're consuming fuel at 100% capacity, the modulating boiler can fire down to as low as 20% of its capacity and then modulate all the way up to 100%. Burner modulation combined with condensing technology promises huge energy savings, providing your customer with a technology that lowers energy costs for the future.
UPCOMING TRAINING AND EVENTS
December 5-8 8am-5pm BPI Heating Professional Training
Learn how to optimize the performance of heating equipment to help save energy and ensure occupant comfort, health and safety. Register online at sunyulster.edu/ce or call 845-339-2025.
Outdoor temperature has the greatest impact on a home or building's load by far. Simply incorporating the outdoor reset function that comes with a mod/con boiler's operating control can mean big energy savings. The outdoor reset tells the boiler whether it's a cool autumn day or a frigid winter evening, enabling the boiler to deliver the appropriate water temperature needed for the weather condition. Features like the boiler reset add up to reduced energy consumption and more comfortable spaces. Be sure to look at our increased, limited-time incentives for natural gas high-efficient equipment rebates here.
Conversion Incentives Expire Soon
Central Hudson is currently offering a $1,000 incentive for eligible residential customers and $1,500 for eligible commercial customers who choose to switch to natural gas heat before the end of 2016. Customers who sign up to make the switch can combine the incentive with existing rebates for energy-efficient equipment like boilers and furnaces to further reduce the out-of-pocket burden. If you have questions about how to offer combination savings to your customers, or if you have customers you think may qualify, email Tom Wolf.
Be "Efficient" with Your Time
Earlier this year, Central Hudson deployed the Power Rebate App for HVAC and domestic hot water system measures installed in residential homes. We're actively looking for more Trade Allies to give it a try. Download it today and let us know your thoughts. We designed the tool to eliminate pain points that are common to the data requirements of energy efficiency programs. Let us know if it's working to make your job easier! The app is available for both iOS and Android devices and includes a short tutorial. If you or your technicians would like on-site training or to participate in a training web conference, contact Melissa Decota to schedule a half-hour training.