Summary: Here is a photo tour of a successful VRV installation in an operational hotel.
VRV HVAC systems are making their way onto the American scene. Although the VRV technology is common in Europe and Japan, it is a newcomer to America. As such, there are few installations for engineers to observe. At the Sheraton Carlsbad Resort & Spa, California, the Mitsubishi City-Multi VRV system has been successfully installed. I visited the site and was impressed by the equipment and performance. Most notably, the guestroom unit is almost completely silent. This photo tour was made possible by Bruce Zelenka who enthusiastically allowed me to see all the pieces of the system from the roof to the guestrooms.
Bruce Zelenka was instrumental in getting the Mitsubishi City-Multi VRV system installed in the Sheraton Carlsbad Resort & Spa.
The condensers are modular and can be placed like soldiers shoulder to shoulder. Here they are about six inches apart, but if space is at a premium, they can be shoved completely together.
A custom curb is used to create a platform to support the condensers.
The refrigerant piping is light weight and can be routed above the roof membrane on off-the-shelf supports. Here is an example of the piping stacked two layers high.
Here is an overall view of the piping neatly racked across the roof. The electrical is extended through roof jacks from disconnect switches mounted on the wall of the parapet. Alternatively, the disconnects could be located at the roof penetration, but this is a cleaner installation.
The piping transition from the roof to a shaft down the building is shown here. Typically, refrigerant piping penetrates a roof with a roof jack, but with this large number of pipes, it is more efficient to create a roof hatch that handles a bundle of pipes. Also, the risk of a roof leak is very low with this detail.
The BC Controller is what Mitsubishi calls the unit which manifolds the refrigerant lines to the guestroom units. The best analogy to describe it is an electrical branch panel. Only one pair of refrigerant lines extend to the roof like a panel feeder, and each guestroom unit is separately served by refrigerant lines like branch circuits.
Looking up at the ceiling of the corridor, the refrigerant piping can be seen routed horizontally.
In a guestroom the fan coils are mounted in ceiling spaces near the corridor. This is no different than a four-pipe fan coil installation.
In this installation, the air filter is mounted behind the return grille to simplify filter replacement.
This is the standard Mitsubishi thermostat. This thermostat is under review by Marriott and Hilton for acceptance in their hotel brands.
Mitsubishi has a fantastic design, but there is still no magic to deal with condensate. Here the condensate from the fan coil unit in the ceiling is piped to the bathroom lav trap.
Mitsubishi offers a variety of fan coil unit styles. Here is a four-way cassette unit suitable for a kitchen or work area. This unit is installed without a ceiling, but as the trim would indicate, it is intended for a ceiling installation.
Mitsubishi has a special condensate trap that does not require a vertical loop. This simplifies installation in ceiling cavities with limited clearance.
This wall mounted style of fan coil is an economical alternative to a built-in type for a guestroom. Although this installation made no attempt to conceal the electrical power or the condensate drain, these units can be installed in guestrooms with a clean look not too different than a PTAC. However with this unit, it is mounted high on the wall and does not require any floor space near the outside wall. I have seen these units successfully applied to a college dormitory.