TEC Auto Test in "Semi-Auto" mode

[Sean Maxwell]

We have had reports of Passive House testers having the TEC Auto Test software start sampling before the pressure in the house had equalised. Sometimes it can take a full minute for pressure to equalise in a large, tight house. The software thought the pressure was changing slowly enough that it was “stable”, and so it started sampling, when in fact it was still creeping up. The result was that the software held the fan speed steady and started sampling, but the building pressure kept going up and the fan flow kept going down!
===========
From Jake McAlpine at TEC:
TEC Auto test does not have different modes like TECTITE, but you can achieve the same thing as the semi-auto mode:

• You can force sample at any point (other than a low fan pressure situation) by hitting the green sample button.
• You can override the automatic fan adjustment by manually adjusting the fan speed with the slider within Auto Test.
• Once you override the automatic fan adjustment Auto Test will not return to automatic fan speed adjustment until a sample is taken.
• If you manually use the slider to bring the building pressure into the range of the target tolerance, Auto Test will automatically sample, or as described above, you can force sample at any point.
• Once a sample is taken the app will begin automatically seeking the next pressure.

===========
I was just playing around with the app. If you take manual control of the fan speed slider, the target search time parameter is ignored and you can hit sample whenever.

But the target tolerance parameter is still active. I would advise to reduce the target tolerance as much as possible so that the program is never satisfied and you have to hit Sample. Looks like the lowest it can be is 1 Pascal.

Using these methods, you should be able to use the TEC Auto Test app in a Semi-Auto fashion.

 

[Paul Carling]

Alternatively you could just do a manual test and not have any issues at all because you can take the readings when you know it has stabilised. It also means that you don't need to adjust the settings between a normal test and one on a low energy building.

 

[Sean Maxwell]

Alternatively you could just do a manual test and not have any issues at all because you can take the readings when you know it has stabilised. It also means that you don't need to adjust the settings between a normal test and one on a low energy building.

Agreed Paul. I can't wait for the ATTMA app to be ready to record from manometers as well. The ATTMA app is already quite handy at taking manual measurements, and paired with the on-board time averaging functions of any modern manometer, should be good to conduct a fully compliant test on even a tight building in windy conditions.
I'm trying to get people to not use Auto Test, which is TEC's iOS software, because it doesn't yield a file format that will be accepted by Lodgement. That would be a wishlist item for Lodgement.

 

[Sean Maxwell]

From Jake MacAlpine at TEC:

The Target tolerance remains active after you manually control the fan with the speed controller on the DG-1000, so you could manually try to get it in the range, and it would sample for you. However, I would recommend changing the following default setting in the app:

• Change Fan adjust rate from 2 down to 1 or 0.5
• Change Target tolerance from 2 down to 1
• Change target search time from 90 up to 120.

This set of changes will make the fan adjust slower, seek a smaller target, and look for it longer. This should give the fan more time to fully pressurize the space without as much overshooting.