Many of our competitors don’t bother with having a design department. After all most manufacturers provide generic schematics of how to install a ground source heat pump and so they rely on their onsite team to work out where and how to fit things together, and their commissioning engineer to make it work.
We don’t work that way. We design our installations, review and sign them off before the work starts, and update them to provide drawings of record after the practical work is completed. Obviously that costs more, so what do we do and why do we do it?
- We want to make sure the system does exactly what it should and there are no unpleasant surprises.
- The actual performance that a heat pump system delivers depends entirely on how well it is designed. Our systems consistently run at high efficiency and we know that the money invested in making sure the system is designed properly and the right equipment is chosen is the deciding factor that determines how well it will perform in practice, and therefore determines the lifetime cost of ownership.
- Heating equipment can be bulky and the space it fits into is always at a premium, no matter whether the house is large or small. We frequently find that the hardest part of the design process is making sure that all the equipment needed fits in the space available and that space is properly shared with all the other uses for it, whether that is for swimming pool equipment, a utility room, or even a home for the dog!
- A clear set of designs makes sure that the job is done properly, and allows us and other contractors to manage the work on site. This way the trenches are dug in the right place, boreholes are drilled as needed, and the team doing the house plumbing know how their work fits with ours.
- Once the practical work is completed the designs are updated to provide drawings of record for long term maintenance of the system. In an installation of any complexity it is very hard for someone coming back to the site in some years’ time to understand how it works. Keeping proper records is essential.
We create a number of design documents covering the different aspects and phases of the work. We create a hydraulic schematic diagram showing the interconnection of the different system components (a Piping and Instrumentation Diagram, P&ID for short). We also create a plan view of the plant room layout, and where necessary a 3D-model to visualise the plant room together with the equipment to make sure that it coordinates properly.
We do a trenching diagram that shows where the trenches should go for the ground collector and the flow and return pipework to the plant room, and, where appropriate, the location of boreholes. It will also show the pipes that run in these trenches and any special construction work or building penetrations that may be required.
Once the essential mechanical design is completed we will also create electrical wiring diagrams for our engineers to work from and to allow them to work effectively with other electricians on site. Alongside the electrical designs we will create a description of how the system controls work and interact with other systems on site.
Our design team become involved in the project from the start. They are responsible for making sure that the system does what is intended. Normally by the time the contract is agreed the overall concept design is complete but needs to be verified and worked out in detail. We will start by arranging a visit to the site to understand the constraints and capture requirements accurately. The requirements capture phase is ideally quick and simple, but sometimes it can become a long-protracted process involving meetings with architects, main contractors, other Mechanical and Electrical contractors and of course the end client.
Once the design requirements and system concept are clear and verified we will produce detailed drawings of the system. Normally the ground works drawing and the plant room layout are needed first, but the P&ID is the key drawing that captures the essence of the system. When the draft drawings are complete, they are reviewed both internally and with the client and other interested parties. The designs are updated as necessary and once they are all agreed, they are signed off. At this stage we know what equipment that will be required and so will be able to start placing orders. We insist on designs being signed off several weeks before the practical work starts to ensure that everyone understands what is being committed to, that the designs are stable, and that there is enough time to allow the procurement of longer lead time items.
The installation and commissioning can then go ahead on the basis of the agreed designs, and when the practical work is done, we will update the designs as ‘As Built’ drawings of record and issue them at the end of the project.
Our design team brings more than twenty years of experience in mechanical design; Ricardo Silva is our electrical engineer who is responsible for the electrical aspects of our work; and Richard Aplin does all aspects of the designs, especially the control and also does most of our customer training. The team uses a variety of design tools such as AutoCAD, Revit and SEE Electrical Design software, coupled with a number of custom tools designed to calculate the fluid dynamics and key parameters of ground source, air source and water source heat pump systems that we have developed over the years we have been installing these systems.
It is this attention to detail that makes the difference and leads to the excellent performance we see in isoenergy systems. When it comes to the detailed design of a heat pump system, you get what you pay for.