Residential

Our manufacturer's recommendation for calibration is as follows:

• Retrotec fans: Every 5 years.  
• DM-2 Manometer: Every 2 years  or if the Manometer fails a field check. 
• DM32 / DM32 WiFi Manometer: Every 5 years or if the Manometer fails a field check.

Please review the DM32 and DM-2 Manuals on how to perform a field check.  

This only covers our manufacturer recommendation.  The energy standards (EN13829, ASTM, ATTMA, USACE, etc...) that you are using for test results may have different calibration intervals.  Please consult the energy standards for the specific equipment calibration intervals.

Retrotec recommends you take the maximum number of test points to decrease the uncertainty in your test.

Yes, you can change this default and take only 5 readings according to the Standard but your uncertainty will often be too high and you might have to retest.  Next, you might retest and find the result differs from the previous test by 10% or more making you lose confidence in the results. Retrotec defaults that include taking 10 test points and longer baselines will optimize your tests and give better results. 

You might save a few minutes by testing to the minimum allowed by the Standards but in the long run, your test results will be poor. Officials look at high uncertainties and poor repeatabilities between your tests and wrongly conclude your equipment is faulty but the truth is that your test method is faulty.  Please use our defaults as practical minimums and if anything take your tests over a longer time rather than shorter and your results will

*Max current is initial in-rush current. Generators used for Retrotec equipment should be inverter type generators, (i.e., suitable for use with sensitive electronics).

In order to do both, you need to be sure you have version 5.8.30 of FanTestic or later. 

In all versions of FanTestic before version 5.8.30,  if you plugged a DM32 into a computer USB to give it power (instead of plugging into the wall adapter) FanTestic would assume you also wanted to use USB Serial connection for control.  FanTestic made this assumption even if the gauge was also connected to the computer over Ethernet (via the Network cable or via WiFi). 

In all versions starting with 5.8.30, FanTestic discovers gauges connected via Ethernet first, so it can ignore the same gauge also found on USB Serial. 

This change allows users to have their DM32 connected for control via Ethernet but also connect the DM32 to the computer USB port for power (if it is more convenient than connecting to a wall outlet).  Retrotec recommends that users use Ethernet connection rather than USB for controlling the DM32. 

I am doing duct testing and use the DW/143 standard (UK).  FanTestic keeps telling me the test is not compliant, what am I doing wrong?

FanTestic checks that you have held the ducts at the test pressure for at least 900 seconds.  If you do not, the test will show as not compliant.  If you did a manual test and are entering the information into FanTestic, be sure to enter the time over which the test pressure was held.  If this is greater than 900 and your other test conditions are correct, the test will show compliant. 

Compliance means the test conditions comply with the stated requirements for a test  in DW/143.  Pass or fail means that the measured results are within the required level.

The big issue is exhaust getting into the house. Duct leaks from the supply side cause the house to have a negative pressure, which can cause air to get pulled in from the garage. Exhaust entering the home can be dangerous and can lead to health issues.

The first step is to find what the maximum house depressurization would be with combinations of the airhandler on, closed bedroom doors, and any exhaust fans running. Do what you can to eliminate these pressures. Check to make sure there aren't any air intakes (returns) inside the garage.

To determine how leaky the garage to house connection is test the house leakage at 50 Pa, then pressurize the garage to 50 Pa; if you see any drop in flow, there's a connection between the two.

Next, depressurize the house and use a smoke puffer to test the garage to house connection. Seal everything between these two zones. 

Modular Panels are designed to be placed into doors that are not well sealed.  The panel leakage for the Modular Panel is about 14 square inches compared to about 3 square inches for the Aluminum Frame and Cloth and around 1 square inch of leakage for the upgraded Aluminum Frame with snap together corners.  These three panels represent three typical doorways: 

1. Poorly weather-stripped which would have an approximate 1/16 inch gap which equals about 14 square inches leakage;  
2. A well weather-stripped and adjusted door would be around 3 square inches or leakage; 
3. A super tight door could be as tight as 1 square inch of leakage and can even have less.

One rule of thumb is that all standards require the blower door panel to be leakier and never tighter than the existing door.  The Modular Panel qualifies here.  It is likely that the Aluminum Frame and Cloth are tighter than the existing door.  In either

The exterior pressure reference for the differential pressure measurement across the door panel is provided by the red tube.  The exterior pickup location must be chosen to minimize the influence of wind, sun and atmospheric pressure on the differential measurement, or measurements must be taken to allow correction for these influences.  Each standard defines what is expected in terms of the exterior reference pressure measurement.  Use Table 2 to determine where best to locate your red tube depending on the standard procedure you are following.

Table 2:  Locations for Exterior Reference Pressure Pickup as required by the various Standard Procedures

I have a Energy or Enclosure Integrity Test to perform.  How many fans do I need to properly run the test?  Do I have enough fans to run the test?

We have created two tools to help you figure out how many fans you will need for your test. 

Download either the Blower Door or Enclosure Integrity version of the Number of Fans Calculator. 

Next, open the file in excel and "Enable Editing" when a security warning appears.

Fill in all the fields highlighted in blue.  The number of fan results are highlighted in green.

Here is what the Blower Door Number of Fans Calculator looks like:

And this is what the Enclosure