Quality assurance

 

Septic Heaters undergo extensive testing during production.

• All electronics are tested at a UL certified manufacturing shop.

• Completed units also go through an operation test at a temperature of -20º F.

 

Prototype Field Tests       

We placed 12 Septic Heaters placed around the state of Minnesota and 1 in Alaska the winter of 2003-2004.  The septic systems on which we tested had been freezing just prior to the installation of the Septic Heater.  In all the cases, the Septic Heater has been 100% successful at preventing the septic systems from freezing.  Based on our testing, we have incorporated improvements into our production model to make it universal (it works on all septic systems) and ensure long product life and superior performance.

 

View test site details and tester comments.

 

Concept Test

We completed over 400 hours of Septic Heater testing in a controlled environment during the fall of 2003.  Twin City Testing (TCT) installed temperature monitoring equipment including thermocouples, a data logger, and a laptop computer to read and store data.

Testing Facility
We conducted the Septic Heater testing in a refrigerated semi-trailer that was divided into three chambers.  In one chamber we had a small lab that was kept warm and contained all the sensitive computer monitoring equipment.  In the second and largest chamber we had 150 feet of sewer pipe strung out with temperature sensors at various points within the pipe.  This chamber represented "below ground" and was kept at 15-20° F, the temperature of frozen ground.  We also had a water reservoir representing the septic tank in this chamber from which we could trickle water into the pipes that would end up in a drop box.  Water was collected in a stock tank and pumped back up to the reservoir.  The third chamber contained the Septic Heater attached to an access pipe from the drop box in the second chamber.  The third chamber represented outside airtemp (intake air for the Septic Heater).  We varied the temperature of the third chamber from 35° F to -20° F.

 

What we measured
We monitored the temperatures of the pipes at 6', 30', 45', 90', 120', and 150' from the drop box.  We monitored the drop box water temperature (at the surface and below the surface), the air intake temperature, heater output temperature, and ground temperature.    For ground temperature, we measured the air temperature at two different points in the second chamber and used the average in our result charts.

 

Results
With -20° F intake air temperature the Septic Heater kept the drop box and 110 feet of pipe from freezing.  With temperatures above 0° F, the Septic Heater consistently kept 150 feet of pipe above 32° F.  The average length of sewer pipe from the tank to the first drop-box (where the Septic Heater is typically installed) is from 25 – 50 feet, so we are very pleased with the performance of the Septic Heater.

With air temperatures below 0° F, the Septic Heater runs continuously, maintaining a water temperature of about 40° in the drop box.  With air temperatures above 0° F, the Septic Heater runs for 2-3 hours, heating the water in the drop box to 45° F, then shuts off.  It takes the water in the drop box about 3 hours to cool to 35° F, at which point the Septic Heater re-activates.  This on/off pattern continues as long as the drop box water naturally remains at or below 35° F.

We tested with and without a trickle of water running through the pipes.  With a trickle of water, the drop box water took longer to heat and cooled off more quickly.  (The water entering the drop box was cold after running through the cold pipes.)