We've moved in!

We did move in straight after the final air-test. Thankfully this gave a final figure of 0.5 air changes per hour when tested at 50 pascals. We achieved 0.61 on the depressurisation test and 0.39 on pressurisation. The large difference between the figures was, according to air testing expert Paul Jennings, almost certainly caused by a failure in the membrane. Liam thinks some tape had come unstuck. This shouldn't happen with the tape used but we certainly had a dodgy roll of tape that caused problems with the need to re-tape in places. Clearly some faulty taping was missed. The other area of failure was in the sand-cement parge coat in Bed 2. Air could clearly be felt coming out of the stud wall through the electric sockets. Others should be able to realistically target an overall 0.3 air changes per hour when major works are undertaken in an existing property.

We are enjoying living in the house - even the cat although he no longer has a cat-flap. The only area that has caught us out is the heating. PHPP shows a maximum demand of around 1050 watts and the in-duct heater can supply 1200 watts so we shouldn't have a problem. What I failed to appreciate is that the heat is only delivered to rooms with air supply ducts - 4 in our case. However 3 of these are on the first floor with the other supplying the lounge. There is no supply to the basement. So if we only used the in-duct heater we would be more than 3 degrees warmer on the first floor than the lower floors. This is too much for comfort. Thankfully we anticipated heating issues in the Kitchen and Basement and have Redwell heaters in these locations (350 watts in the Kitchen) and (250 watts in the Basement). However we still have an issue in the lounge but we will address this by adding more heat. This should then enable us to lower the setting on the thermostat controlling the in-duct heater. Overall this shouldn't use any more energy just get it distributed more efficiently.

The general learning points seem to be to just use the MVHR for ventilation. Use a different solution for space heating - one that can address the energy requirement of each space. Also use a different solution for DHW (that is not the same system used in the space heating. The DHW system is proving to be a spectacular success. The plant room is within 0.5 degree of adjacent areas because of the very low losses from the Sunamp system.