Positive Input Ventilation help required

Ianlx

Hi all - first post, here goes...
After views on PIV systems, in particular Nuaire Drimaster 365.
I have a 1930's 3 bedroom semi with the following: UPVC double glazing (no trickle vents), adequate loft insulation, cavity wall insulation.
The current warm weather situation finds the upper rooms with very little air flow and very stuffy and very hot at night when the outside air temperature is lower than inside (this is definitely worse since the cavity insulation was fitted). We are limited to the amount of open windows etc with a noisy main road and young kids, and even with windows open on a still night there is no air movement.
With the Drimaster 365 the option of taking air from loft or outside dictated by a adjustable thermostat sounds promising but looking for anyones real world experience of this?
My concern is - will a central vent position provide enough air flow to rooms and dare I say it, could this knock a few degree's of the air temperature when it is being sourced from outside?
Looking forward to your reply's.
Thanks.

modelreject

Not the most impartial to give you advice but I would recommend these guys as a friend has used them, Beam Central Systems