ASHRAE 90.1-2007: Minimum Efficiency Requirements (Heat pump)

Hello Everyone: I am working in an office building project located in Galicia (Spain). We are carrying out the selection process of the heat pump for the air conditioning of the building. According to ANSI/ASHRAE/IESNA 90.1-2007, this heat pump (>40 kW) must comply the following minimum efficiency requirements: COP (8.3 ºC db / 6.1 ºC wb): 3.2 (as of 1/1/2010) COP (-8.3 ºC db / -9.4 ºC wb): 2.0 The heat pump we are evaluating has a COP of 3.5 (8.3 ºC db / 6.1 ºC wb). However, the manufacturer of the heat pump does not have the COP value at -8.3 ºC. They send us a letter explaining that this heat pump doesn’t operate under -7 ºC. We have analyzed the historic minimum site temperatures, and the minimum recorded temperature is -2.7 ºC, so the heat pump would never work under -7 ºC. Additionally, the manufacturer has given us the COP values at various temperatures. With these data, we obtained an equation that relates COP to temperature. The coefficient of determination (R2) of this equation is 1, and our estimated COP with this equation at -8.3 ºC is 2.2 (above the minimum ASHRAE value). This is the efficiency value which would have the machine assuming it could work at -8.3 ºC. Thus, could we achieve the ASHRAE requirements compliance taking into account these considerations? Thanks in advance!