TO CONDENSE OR NOT TO CONDENSE

High energy prices have created a consumer driven shift toward high efficiency modulating/condensing boilers. Yet many remain skeptical of the true value of a condensing boiler, especially in high temperature applications, such as baseboard or hydro air. However, the high efficiency boiler creates savings by modulating its firing rate down. For example the Sync boiler, by Lochinvar is equipped with a 10:1 turndown ratio and can fire at a rate as low as 10% of the full rated capacity of the boiler.
Now let’s talk about condensing. In a condensing boiler, when flue gases condense, or change state from a gas to a liquid, latent heat gets absorbed by the water in the heat exchanger. Instead of flue gas heat going up the chimney, its heat is now applied to the system water. The lower the return water temperature, the greater the condensing will be. Since condensing begins at around 135 degrees, designing your system with a 25° delta T and a supply temperature of 160° will yield return water cold enough to condense. With a properly sized boiler there are few days each heating season that require water temperatures over 160 degrees. In fact standard baseboard can still provide heat with water temperatures of 110 degrees.
If that isn't enough to sell it, how about rebates and tax credits of $2,500.00 residentially and, depending on which gas utility, as much as $15,000.00 commercially per boiler.