Large amount of Condensation on uPVC frames

If there is condensation between the glass ..then there is a problem in glasses ..glass should be energy sufficient..A rated or C rated ...if it is not between the glass it's mean house it's happening due to cold weather ...and need more heating in house ..

To reduce condensation on uPVC window frames, you can consider the following steps: Improve ventilation: Ensure proper ventilation in the affected areas to allow moisture to escape. This can be achieved by using exhaust fans or opening windows periodically to exchange indoor air with outdoor air. Use a dehumidifier: Installing a dehumidifier in the room can help reduce indoor humidity levels, which, in turn, can help minimize condensation on the frames. Insulate your home: While retrofitting insulation in an older home can be a significant project, improving insulation in the walls and around the windows can help maintain a more consistent indoor temperature and reduce the temperature difference between the frames and the indoor air. Install weatherstripping: Ensure that the windows are properly sealed with weatherstripping to prevent cold air from entering and warm, moist air from escaping. Use thermal curtains or blinds: Installing thermal curtains or blinds can help create a barrier between the window frames and the indoor air, reducing the temperature difference and the potential for condensation. Remember that condensation on window frames, while not ideal, is not necessarily a sign of a problem with the uPVC windows themselves. It is often related to the overall environmental conditions in your home. By taking these steps to reduce humidity and improve insulation, you can help minimize condensation on your window frames and maintain a more comfortable indoor environment. If you continue to experience excessive condensation or if you have concerns about the condition of your uPVC windows, it may be a good idea to consult with a professional for a more specific assessment and recommendations.

The bay angles are joined by Aluminium bay poles, these can cause condensation to form around the area, also alot of fitters do not seal the bay poles to the PVC frames, especially at the bottom where they sit on the welded cill, the best course of action is to remove the bay pole covers, use expanding foam both inside and outside, allow to cure, scrape flush once cured, then re-fit the plastic covers, this will insulate the Aluminium poles.

I agree with the filling answer however if you have no trickle vents installed this can also lead to it