I agree. HKD Energy funded a new air to air heating system at Southwater Church Room - which is now loads more comfortable. The old night storage heaters can be chucked out.

This is 6 months in a suburban/rural location. The dirtiest one is the F7 supply, the other is the G4 extract

Make your money go further by understanding the costs and options in a home energy efficiency retrofit
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Since the RdSAP 10 regime was adopted on 15th June, homes with heat pumps and heat recovery ventilation can now get a sensible rating. Why A99 not A100 in this case? Didn’t want to litter the roof with higgledy piggledy solar panels

Here’s the bible very much recommended

Not at all - take this central window on a 70s retrofit. The room inside is dark, needs max light. But at certain times the southern sun is blinding. External blinds on a triple glazed window sort this problem perfectly - and room stays < 25C when it’s 34C outside. Brise soleils would be silly here.