Attic Heat Harvester
heating system efficiency, AHHS 1 floor installation


Heat your home for the cost of running a light bulb

Attic Heat Harvester Controller

reduce heating costs - buy now The Attic Heat Harvester Controller that is based on a powerful micro-controller, is designed to give incredible heating system efficiency. The controller also provides accurate attic heating system performance monitoring.

The system functionality is defined by a program that is pre-programmed into the device by the manufacturer. Attic Heat Harvester Ltd can modify the system functionality by developing different programs to meet the requirements of innumerable other applications.

When operating as a control system for an attic heat harvesting application the core function of the Attic Heat Harvester Controller is to compare two temperatures. If temperature 1 exceeds temperature 2 by a user pre-set amount a relay is closed, supplying ac power to a fan. Many other functions are also integrated into the Attic Heat Harvester Controller, these include: air valve control, calculation and display of system performance data, the user ability to pre-set a number of system parameters to precisely suit the application, a programmable timer, and system test features.

attic heat harvester controller

In the Attic Heat Harvester guise the controller has a 2 line x 8 digit 'back lit' LCD display, 3 key buttons, 2 temperature sensor inputs, and 2 or 3 relay outputs. One relay supplies ac power to a fan, a second is used to open and close the air valve, and the third optional relay is used to supply ac power to an optional attic cooling fan.


The Attic Heat Harvester Controller display has a number of display modes that:

a)    display system status and firmware version during the power up sequence - this information should be provided should you need to contact the manufacturer with a controller related query.

b)   display attic and room temperature - the 'normal' display mode

c)   display heating system performance monitoring data

d)   display the user pre-settable system parameters which can be changed by using the + and - keys

e)   display the results of system tests

f)   enables Attic Heat Harvester heating system performance monitoring data to be reset, i.e. cleared

g)   enables the fan and air valves to be manually operated

Attic Heat Harvester Control System Block Diagram

heating system performance monitoring using AHHS heating system performance monitoring with using AHHS
Attic Heat Harvester Controller
Block Diagram
Attic Heat Harvester System Schematic

The diagrams show the controller internal main system components and the Attic Heat Harvester System components connectivity.


Attic Heat Harvester Heating System Performance Monitoring

Attic Heat Harvester Performance data display mode enables the user to monitor system performance, the displayed data includes:

a)  Current power being generated in kWs, and the current system efficiency, e.g 15.3 = 1,530%, and 34 = 3,400%

b)  Total power in kWh and total system efficiency for the system since it was last reset

c)  The system heating cost, i.e. the cost of the electricity used by the system to transfer attic heat

d)  Fan operating hours and the average attic - room temperature since the system was last reset

e)  The un-used heat, i.e. the additional attic heat that was not required because the user pre-set room temperature had been achieved,

f)  The Attic Cooling Cost - for systems supplied with the attic cooling fan control option.

g)  The maximum and minimum attic temperatures seen

h)  The current time, if this has been previously set

The Attic Heat Harvester Controller Manual gives detailed performance parameter information and screen shots.


Attic Heat Harvester Pre-Settable Parameters to Optimise Heating System Efficiency

System Parameters configure the controller to meet your application's needs, system parameters are:

a)  Attic - Room temperature - sets how much higher than the room temperature the attic temperature has to be before the fan is turned on

b)  Maximum room temperature - sets the room temperature at which the fan switches off preventing further heating.

c)  Fan Flow - defines the air flow rate

d)  Heat Fan Power - defines how much power the heating fan

e)  Cool Fan Power - defines how much power the cooling fan (if fitted) consumes

f)  Electric Cost - defines the cost of electricity per kWh

g)  Metric or English units - defines whether the display is to operate in °C and cubic meters per hour cmh, or °F and cubic ft per minute cfm

h)  Current Day and Time

i)  Weekday Heat On hour and minute

j)  Weekend Heat On hour and minute

The Attic Heat Harvester Controller Manual gives detailed pre-settable parameter information and screen shots.