Natural Ventilation

The Geyser building is a naturally ventilated building which utilizes the natural warming and cooling effects of an active façade to control the indoor air temperatures.

The building has a double skin façade (DSF) which is a double layer of glass between the internal office space and the exterior environment. This forms a natural temperature controlled cavity with open-able shutters at the top and bottom of the cavity and windows and trickle ventilators across the cavity into the tenancy space. These shutters are activated by internal and external temperature sensors (refer winter and summer operation figures below). Wind and rain sensors override the opening of the windows in the event of bad weather.

Naturally ventilated buildings have a wider thermal comfort range that mirrors the outdoor air temperature, therefore it is important that occupants accept temperature leniency, dress accordingly for personal comfort and actively manage the internal façade. The building is designed to achieve an indoor temperature range of 19-25 ºC in Winter and 21-27 ºC in Summer, active management from the tenants is required to achieve these temperature ranges as instructed below for each season. Fine tuning of individual zone temperature set points can be made via the BMS. The BMS is also capable of monitoring and logging room temperatures.

Naturally ventilated buildings are similar to air-conditioned buildings in that there is a person to square meter ratio to ensure desired tenant comfort, in Geyser the desired ratio is one person per 10sqm. If you breach that ratio your tenancy will be prone to overheating, and if you fall far short of that ratio your tenancy may also experience cooler temperatures in winter.

Winter Operation

Generally, the outer skin operable windows remain closed throughout the heating season. The top and bottom cavity dampers are closed out of working hours to retain heat within the buildings. Internal windows are manually operable by building occupants.

Heating. Each tenancy has ceiling mounted electric heaters for the cooler months to maintain acceptable thermal comfort. They operate on timers but each tenant has an override switch to turn the heating back on if required.

Summer Operation

Generally, the top and bottom cavity dampers remain open 100% during the Summer season (unless raining), the internal windows shall be manually operable by building occupants whilst the windows in the external skin shall remain open 24hrs to provide assisted cross ventilation effect.

Cooling. The late afternoon sun is particularly intense in New Zealand and tenancies on the Western side should use their blinds to mitigate solar gain heat spikes inside tenancies.

Night purge: At night the inner windows are recommended to be left open for night time flush ventilation during the summer months to refresh the tenancy spaces and reduce peak daytime temperatures within.

Creating an air flow: To encourage an air flow, where possible, make sure opposite sides of your tenancies have their windows open.

Don’t block windows or place cabinets to obstruct air flow through your space.

Consider impact of the use of full height partitioning within your space and how this will impact airflow in the area.

Dress according to personal comfort at the designed set temperature of 21.5 C.

Outdoor Air Supply

In addition to the buildings natural ventilation features, an outdoor air supply has been provided to each tenancy to enable the tenant (with Landlord approval) to add individual air conditioning to the tenancy space.  Spatial provision has been made within the service risers for tenant AC refrigerant pipe work and on the roof for limited outdoor condensing equipment based on a commercial variable refrigerant volume (VRV) system.

Last modified: 04 Mar, 2019