Peak lopping units are increasingly being used by developers to ensure compliance with Part O. The units include a cooling module that, when activated, provide a degree of cooling to the dwellings, helping them achieve compliance. In specifying these units, developers should also be aware of the following:
- Size and weight: Some models are large (exceeding 2000mm in height and 700mm in width) and heavy (over 100kg), requiring appropriate cupboard space and structural reinforcement.
- Energy efficiency: These units may not be as energy efficient as traditional MVHR units, impacting SAP calculations negatively. Further they will use additional electrical energy for the cooling unit.
- Ventilation Rate: Design ventilation rates are relatively inflexible due to the limited number of peak lopping products in the market.
- Duct Size: Ducts need to be adapted for the increased flow rates, and appropriately insulated and soundproofed. Increased void spaces may be required.
- Modelling Challenges: To demonstrate the benefits of the peak lopping units, modelling must be carried out carefully and competently. We have coordinated with manufacturers and software providers for accurate results in our models.
- Limited Case Studies: We recommend that developers should carry out post-occupancy evaluations due to lack of available case studies, especially on cost-effectiveness.