Condensation Control Unit Mr Venty Piv System

[YorkieJohn]

'Eco-Loft' Positive Input Ventilation System - PIV Loft Mounted

If anybody has one of thes units I would be grateful for advice on the following questions
On the above unit there is a setting for the temperature status of above 25 degrees , above 19 degrees , and below 19 degrees . What do those settings mean ? Also a lot of people criticise these units for blowing cold air out into the area where it is installed , does the heater on them make a noticeable difference to prevent that ?

[Buenchico]

I assume that the settings refer to the ambient temperature in the loft space. In particular, I note that the technical specifications document states:
"The PIV Air Source Unit has the additional facility to draw air from atmosphere during the warmer months of the year when the temperaure in the loft space exceeds 25°C. This provides efficient perception cooling into the property and maintains the required level of ventilation continuously throughout the year"
So I assume that the householder is required to choose the 'above 25 degrees' setting in order for that facility to work efficiently.
http://www.justfans.co.uk/catalogues/PIV_Loft.pdf