For a brand new building that is not yet out of the ground you can only work from drawings. However, since the large majority of installations are for existing buildings, we will assume, for the purposes of this article, that the application is a two-story office building, with approximately 160m2 per floor and multiple segregated cellular offices and open plan areas.
When they first make an enquiry most customers do not have a clue about how much air conditioning costs, so it is important to establish what their budget is. Some customers maybe willing to discuss this but others will not, especially if they have already had a price from someone else and are shopping around for a better deal.
Failing this, try to give them a ballpark price early on to establish whether it’s worth them, or you, proceeding any further.
Assuming this all goes well, the next step is to carry out a site survey during which the following information needs to be gathered:
- Size of room(s) – internal /external walls and orientation.
- Number of people in each room.
- Windows – sizes, type (single/double glazed any special coatings, internal blind or external shading).
- Internal equipment heat gains (copiers, lights, PCs, servers etc).
- Building construction (suspended ceiling, void depth, and external wall construction).
- Location of power supplies and space for external equipment (roof, ground, wall mounted) Is the roof strong enough to take the weight of the proposed equipment? If in doubt the client or their landlord may have to engage the services of a structural engineer.
- Roof access. Can the proposed equipment be manhandled up to and onto the roof without needing a crane? Take measurements of all stairways, lift openings and doorways along the proposed route up to the roof.
- Space and possible routes for pipe-work and/or ducting.
- Is there any additional mechanical ventilation required to meet building regulations? This is often the case if a new occupied internal space/office is created with no external opening windows.
- Check with the customer exactly what he requires in terms of temperature control and whether the system is for cooling only or heating and cooling with independent control for each area. It is also very important to find out if the client has any future plans to expand or change the floor plan in any way. If he does, then now is the time to consider building in flexibility to accommodate those future changes. Chances are the client will be more interested in limiting the initial cost, in which case it is also important to point out that a system designed to a price for immediate requirements will cost more to modify or add to in the future.
Having undertaken the site survey the next step is to take all the information gathered back to base and crunch some numbers to see what the cooling/heating loads will be.
At this stage you also probably have an idea of what type of system(s) you will be offering, but that is for the next instalment.