chadfireski
New member
Selling my Used Hottop KN-8828B-2K+
Located in Davis CA
KN-8828B-2K+
* Dual K thermocouples monitor bean temperature and environmental temperature
* Auto and manual control roasting
* Temperature, time, fan speed, and heating element power can easily be modified during the roast
* Auto mode allows operation much like older models as well
* Numerous safety functions including manual emergency eject
* Capacity: 225g - 300g per roasting (250g optimal)
-As you can see from the pictures I did a RAF (Reverse Air Flow) Mod, you can read about it below or at
The most significant difference between a factory Hottop, and the RAF-1 Extreme, is the direction in which the air flows through the roaster. In order to reverse the direction of the airflow, I have installed an extraction pipe above the roasting chamber; that pipe is linked to a plenum mounted at the rear of the roaster; attached to the plenum is the original exhaust fan, which operates in the same way as it does on a factory Hottop.
With this modification, turning ON the exhaust fan creates negative pressure inside the plenum and in the extraction pipe; that negative pressure causes hot gases to be extracted from the roasting chamber through the opening at the top. More importantly, cool air is now pulled into the hot roaster through openings in the rear housing, and openings in the base of the Hottop; this cool air effectively shields the roaster?s most critical components from unpleasant chaff, stubborn tar-like deposits, and extreme heat levels.
Located in Davis CA
KN-8828B-2K+
* Dual K thermocouples monitor bean temperature and environmental temperature
* Auto and manual control roasting
* Temperature, time, fan speed, and heating element power can easily be modified during the roast
* Auto mode allows operation much like older models as well
* Numerous safety functions including manual emergency eject
* Capacity: 225g - 300g per roasting (250g optimal)
-As you can see from the pictures I did a RAF (Reverse Air Flow) Mod, you can read about it below or at
Homeroasters - Home Roasting Coffee Community - Discussion Forum: Enhancing My HotTop (5.1 of 5) ? Extreme Mods
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The most significant difference between a factory Hottop, and the RAF-1 Extreme, is the direction in which the air flows through the roaster. In order to reverse the direction of the airflow, I have installed an extraction pipe above the roasting chamber; that pipe is linked to a plenum mounted at the rear of the roaster; attached to the plenum is the original exhaust fan, which operates in the same way as it does on a factory Hottop.
With this modification, turning ON the exhaust fan creates negative pressure inside the plenum and in the extraction pipe; that negative pressure causes hot gases to be extracted from the roasting chamber through the opening at the top. More importantly, cool air is now pulled into the hot roaster through openings in the rear housing, and openings in the base of the Hottop; this cool air effectively shields the roaster?s most critical components from unpleasant chaff, stubborn tar-like deposits, and extreme heat levels.