Site Progress - Oxford - EnerPHit House
This week my work has mainly consisted of a full rewire of two properties in Oxford. One being a EnerPHit (Passive House retrofit) and one being of standard construction. As you can imagine the EnerPHit property has thrown up many challenges with wiring not normally encountered with traditional built properties - but high levels of airtightness are very much the future of construction. The additional challenges are mainly due to the membrane that is used to keep any air from escaping the property. Any holes in the membrane that were made due to cable runs, were tightly sealed with special adhesive tape to ensure no air loss in the property. Planning of cable runs was very important as not to damage any of the membrane.
Both houses are being fitted with an Air source heat pump. As the demand on the national grid increases these services must be notified to the DNO. Using the correct calculations and with help from ALTO Energy we have got both of the properties approved by the DNO. An ASHP is a type of pump that can absorb heat from outside the structure and release it inside using the same vapour-compression refrigeration process and much the same equipment as air conditioners but used in the opposite direction. Also in some cases they can provide domestic hot water. With its smart programming it can save up 35% more energy than a traditional boiler.
The EnerPHit house is also fitted with a MVHR. Mechanical ventilation with heat recovery. It is a continuous source of ventilation that extracts stale, moisture laden air from a building and resupplies fresh filtered air back in, resulting in a comfortable and condensation free home all year round. As this is a passive house this is a must.
The standard house has been far more straight forward. Choosing cable runs, noggins in stud walls for sockets and switches, downlights in various rooms of the house, chases in walls for backboxes and smoke alarms.
Both properties will be installed with Aico smoke alarms grade D1 Category LD3 to ensure they meet building regs. Also both properties will be fitted with full RCBO fuse boards with SPD type 2. The SPD is a surge protection device. This is a device that protects the whole electrical system from electrical power surges known as transient overvoltage’s. This is mainly to protect household appliances such as computers, laptops, TVs and kitchen appliances. As always onsite health and safety is of the up most importance. Safety boots and the correct PPE are worn at all times. Communication between the different trades on a day to day basis is also very important. This ensures that the whole job runs smoothly.