Apex City Hotel, Edinburgh: Project Diary, Part I

The four-star Apex City Hotel is located on the Grassmarket in Edinburgh, right in the heart of the city. The key selling point is the view, looking out onto the southeast side of Edinburgh Castle, dominated by the dramatic, curved wall of the Half Moon Battery.

Through specialist M&E contractors WMQ, B-DACS was commissioned to install air conditioning for the hotel’s 49 castle-facing rooms, which are set to be renovated in the New Year. Our engineers have been working on the new system since 21^st October and I visited them on site last week to find out more about the project.

B-DACS Engineering Team

When I arrived at the hotel, I found the B-DACS team working in the main corridor on the third floor. Two of the engineers were up ladders, working on the pipework in the ceiling void, while the others were helping out with tools and equipment.

We’ve kept a consistent team working on the project, which is led by Derek, one of our senior engineers. He’s being supported by Darren, an engineer’s assistant who joined us in the summer, and Ross, a former transport refrigeration engineer who’s working on his first full project with B-DACS. Also lending a hand for the day was our project manager, John.

Project Background

We’re installing a Mitsubishi Electric VRF system to serve 49 rooms in the Apex City Hotel. It’s an extensive project, covering 10 bedrooms on the first floor and 13 bedrooms on the second, third and fourth floors. It involves installing 49 indoor units, 4 outdoor units and the connecting pipework and infrastructure. We’ll be working in the hotel until March 2015 and the final rooms won’t be open to the public until May.

Although the work is taking place in the corridors, the hotel will remain fully operational throughout the project. However, with guests and staff free to walk through the area at any time, it’s been vital for all the engineers to ensure everyone is comfortable with the work we’re doing. Keeping the area safe and tidy has been a major priority and that side of things been extremely positive. There have been no complaints from hotel guests.

Mitsubishi Electric VRF Infrastructure

Darren and Ross showed me around the new air conditioning system, taking me downstairs to see the outdoor condensing units and then back up through the floors. They explained how the system would work and where the pipe runs went, passing from the outdoor units, through the chiller room and up the main riser, then into BC controllers on each floor before connecting up with the indoor units in the bedrooms.

The infrastructure is already in place in the corridors on each of the four floors and the main riser. The engineers are now working on installing the BC controllers for each floor, which perform a vital role in Mitsubishi Electric VRF systems. They make it possible to supply simultaneous heating and cooling to different units using a two-pipe VRF system.

BC Controllers

Basically, the outdoor unit sends a mixture of gas for heating and liquid for cooling through the same pipe. However, when it reaches the BC controller, it gets separated. That means the correct phase can be delivered to each individual indoor unit, depending on whether it’s set to heating or cooling. It allows for greater flexibility and comfort, while reducing installation costs and complexity.

In the system we’re installing for the Apex City Hotel, we’re using one BC controller per floor and connecting it to every indoor unit on that floor. As well as working on the system infrastructure, we’ve also fitted the outdoor condensing units, positioning them in the car park at the rear of the hotel.

Next Steps

The first phase of the project is almost complete. Unusually for a construction project, the air conditioning is the only thing that’s been started so far. However, work is due to start on a sample room in the next few days.

It was important to get the infrastructure in place now because it will allow the programme to progress on a staggered basis. When the other trades come in to refurbish the rooms, only a few will be closed at any one time.

All we will need to do in the New Year is install the indoor units – although that will be no small task – everything else will be ready to go.