Q: Do you provide samples ?

A: Yes, we provide samples at cost. Sample fee will be rebate to you during 1st mass production order.

Q： Do you do pre-production sample before mass production？

A： Always a pre-production sample before mass production; Always final Inspection before shipment.

The combustion of natural gas produces water vapor and carbon dioxide etc.  One cubic meter natural gas produces approximately 1.5kgs of water vapor (appx 2M³). The excess air coefficient of the condensing boiler is between 1.2 and 1.3, the dew point temperature is about 54°C, and the general exhaust temperature is about 60°C. When the smoke comes out, it is already in the state of small water droplets, not steam. The white smoke seemed is actually tiny water droplets. Therefore,it is already white smoke before contacting with cold air (in winter) to condense.

The exhaust smoke temperature of non-condensing boiler is above 130°C and it comes out of the flue invisible.When it further spreads out, it will be condensed into visible white smoke (tiny water droplets) by cold air (winter). It therefore appears to have less white smoke than condensing boilers. Some non-condensing combi boiler with higher exhaust smoke temperature, or larger fan power (the flue gas is flushed farther), have less white smoke.

The reason why the efficiency is higher at 30% load than at 100% load is that with the same excess air coefficient (about 1:1), the heat exchange area at 30% load is larger than that at 100% load. That is to say, when the heat exchange area is the same, though the amount of heat received is small, the heat transfer is more effective.

Condensing boilers generally have a modulation of 1:8 or even 1:10.  The minimum power can make 24KW (modulation for 24KW boiler is 1:10). Non-condensing boiler, restricted by the burner, modulation of which can make 1:3, or even 1:3.5, though very hard.

When it approximates thermal equilibrium,the heat load is small. Condensing boilers can work at small load, and the temperature will not rise 2~3℃ higher than the set value. The boiler doesn’t stop but runs at low fire. Generally the heat output power can be increased (almost all condensing wall-hung boilers can be modulated)