INSIGHTS

2025.04.09

MEP Engineering talk. Environment and equipment idea notes Vol. 19

Taking on the challenge in a medium-sized office building
Balancing wellness and energy conservation (Part 2)

Front Place Chiyoda Ichibancho

MEP Engineering designers talk. Environment and Equipment Idea Note TOP

(Main photo: FOTOTECA)

Following on from the first part, we will introduce the efforts being made at Front Place Chiyoda Ichibancho, which is pursuing the ideal form of a modern tenant office building. In the second part, we will focus on the wide range of facilities being undertaken, aiming to set a new standard in tenant office buildings.

Making tenant offices more comfortable: Taking on the challenge of introducing air-type radiant air conditioning

As an effort to improve thermal comfort, one of the components of wellness, air-type radiant panels * were installed on the entire ceiling of the office tenant areas, except for the perimeter area, aiming to create a comfortable air-conditioned space through the effects of micro-air currents and radiation.The air-conditioning system is a typical air-cooled heat pump package air conditioner, but the air supply ducts from the indoor units and total heat exchanger are connected one by one to box-shaped air-type radiant panels, and air conditioning is performed by the radiant effect of the conditioned air temperature and the micro-air currents from holes in the panels.
Since air-type radiant panels are installed in large numbers on the ceiling, it is desirable for the design to blend in with the space, but at the same time, it is essential to balance functionality such as wind speed, static pressure, and airflow characteristics. With the help of design engineers, we created multiple patterns for the size, number, and layout of the holes in the panels, and conducted demonstration experiments with the cooperation of the manufacturer. We arrived at the optimal panel shape.

Intercentral air-type ceiling radiant heating and cooling system "RadiAir".

Left: Air radiating panel. The design blends in with the adjacent rock wool sound-absorbing panels.
Right: Demonstration of airflow characteristics.

In the height of summer just before completion, we measured the temperature distribution and PMV (average predicted thermal sensation declaration) * during cooling. Thermography confirmed that the air radiant panels on the ceiling cooled immediately after cooling operation started, demonstrating the effect of radiation. In addition, the time-averaged vertical temperature distribution showed that the temperature at the height of the occupied area was uniform, and the PMV was stable within a range of ± 0.5 about 15 minutes after the start of air conditioning operation, quantitatively confirming that the theme of "a highly comfortable air-conditioned space" had been achieved.

PMV (Predicted Mean Vote) is a thermal environment index based on six parameters: physical elements of the thermal environment, namely air temperature, radiant temperature, air flow, and humidity, and human elements of the amount of clothing worn and activity level (metabolic rate).

Left: Thermography taken 30 minutes to an hour after the air conditioning started. The air radiating panel on the ceiling is cold.
Middle: Vertical distribution of time-averaged temperature.
Right: Actual measurements just before completion. Checking the PMV meter.
Vertical distribution of time-averaged temperature.
Actual measurements taken just before completion. Checking the PMV meter.

Sustainable and user-friendly electrical installation planning

Our goal was to create a "new standard for tenant office buildings" and to achieve a sustainable, user-friendly electrical equipment plan.

The lighting control equipment in the common areas of the offices takes advantage of the characteristics of DALI (Digital Addressable Lighting Interface), which allows each lighting device to be assigned an address and freely configured, allowing for more detailed control by giving each​ ​lighting device an address, aiming for a lighting plan that takes energy conservation into consideration. For example, as shown in the photo, it is possible to set up schedule control for each lighting device, change the lighting output depending on the time of day, or use sensors to detect when no one is present and automatically turn off the lights in unused spaces, which is expected to have an energy-saving effect.

Left: Schedule control settings for common area corridors, which vary in detail from location to location.
Right: Occupancy control settings for the common area toilet. Different brightness settings can be set for the ceiling and walls. (Two photos: FOTOTECA)

Throughout the building, we have been conscious of creating a "seamless connection with the town." The entrance uses a skeleton ceiling, which is rare for a tenant office building, and incorporates linear lighting that runs from the exterior area to the entrance.
Furthermore, in keeping with facade of "piled stones," the benches facing the street are designed to let light in through the gaps between the stones. Considering ease of maintenance and to allow human intervention, we created a full-scale model and worked with the design team to adjust the placement and dimensions down to the millimeter.

Left: The entrance uses linear lighting that evokes a sense of connection with the town.
Right: A bench installed at the entrance. Light pours in through the gaps. (2 photos: FOTOTECA)
A full-scale model of the bench was created and the dimensions were considered based on feedback from the craftsmen who would actually be installing it.

"Seamlessness" was also a theme in the security plan for the entrance and exit management equipment. At the office entrance and private office areas, we installed card readers and automatic doors that open and close automatically when the user touches a card, while the elevators in the common area of the office have contactless buttons that allow users to register their destination floor simply by holding their hand or finger over them. The traffic flow plan connects the town, office entrance, common area, and private office area comfortably and seamlessly.

We aimed to create a traffic flow plan that would be contactless and stress-free even for visitors who do not normally use the office.

Obtaining BELS 5-star certification for a medium-sized office space

By reviewing the air conditioning heat load settings, adopting high-efficiency air conditioners, controlling the number of outdoor units, ​CO2 control, LED lighting throughout the building, motion sensors, and adopting optimal lighting control, we have reduced annual primary energy consumption by more than 40% compared to the standard value, achieving BELS 5-star environmental performance.

BELS evaluation label BEI=0.58
This design reduces primary energy consumption by 42% from the standard amount.

It is important that tenant office buildings are designed to be easy for workers to use, and facility planning also requires a high degree of flexibility compared to other architectural uses. We believe that this project has demonstrated one solution for architectural and facility planning that balances wellness and energy conservation while maintaining the functionality of a tenant office building. We hope that the ideas and achievements of the various environmentally friendly initiatives in this project will be linked to future large-scale projects.

Designer's Voice

Designer

Mechanical MEP Engineering Department / Joined in 2020

Maho Onoda

Maho Onoda

We were able to find a way to balance wellness and energy conservation in a tenant office building, and I believe that this was a valuable and important experience for me as MEP Engineering for our company. The business operator, contractor, and designer came together as one team, and everyone around us proactively considered various design initiatives from their own perspectives, which made this project a reality. I would like to take this opportunity to express my sincere gratitude.
*Affiliation at the time of project assignment

Designer

Electrical MEP Engineering Department / Joined in 2020

Hirotaka Nagahama

Hirotaka Nagahama

Aiming to create an office building unlike anything that had ever been built before, the mechanical and electrical teams were particular about the design, and I feel that this is the building that was brought to fruition. I have been involved as the main person in charge since my first year at the company, and have been able to experience everything from the early stages of design to on-site completion, which has given me confidence as a designer. I would like to continue designing various buildings at our company, but there is no doubt that this will be a building I will never forget!
*Affiliation at the time of project assignment

Back to Part 1

Data

Property Name

Front Place Chiyoda Ichibancho
Site area

Approx. 1,219.74 m2
scale

11 floors above ground
Completion

September 2024
Design and Construction Supervision

Mitsubishi Jisho Sekkei Inc.
location

23-3 Ichibancho, Chiyoda-ku, Tokyo
Total floor area

Approximately 6,862.78 m2
structure

Steel frame
Main Applications

Offices, restaurants
Construction

Zenitaka Group

OTHER COLUMNS

MEP Engineering Speak: Environment and Facility Idea Note Vol.19

Taking on the challenge in a medium-sized office building
Balancing wellness and energy conservation (Part 2)

Front Place Chiyoda Ichibancho

MEP Engineering Speak: Environment and Facility Idea Note Vol.18

Taking on the challenge in a medium-sized office building
Balancing wellness and energy conservation (Part 1)

Front Place Chiyoda Ichibancho

MEP Engineering Speak: Environment and Facility Idea Note Vol.17

Equipment that supports trust and creativity (machinery)
Air conditioning that creates flexible offices

Nikon Headquarters/Innovation Center

MEP Engineering Speak: Environment and Facility Idea Note Vol.16

Realizing an "Open Kitchen Classroom"
Air conditioning approach

Tsuji Culinary Institute Tokyo

MEP Engineering Speak: Environment and Facility Idea Note Vol.15

Ideas for creating a comfortable space that harmonizes with wood

Kumamoto Tokio Marine & Nichido Building

MEP Engineering Speak: Environment and Facility Idea Note Vol.14

Facilities planning to overcome the "hurdles of wooden construction" for a new era

The Royal Park Canvas Sapporo Odori Park

MEP Engineering Speak: Environment and Facility Idea Note Vol.13

Moving away from simple replacement: How to approach ZEB Renovation (Part 2)

Renovating existing stock to become ZEB

MEP Engineering speaks. Environment and equipment idea notebook No.12

Moving away from simple replacement: How to approach ZEB Renovation (Part 1)

Renovating existing stock to become ZEB

MEP Engineering Speak: Environment and Facility Idea Note Vol.11

Creating a comfortable "air" environment with renewable energy

Takasago Thermal Innovation Center

MEP Engineering Speak: Environment and Facility Idea Note Vol.10

Delivering light, wind, and temperature to the entire space

SEITOKU Kindergarten

MEP Engineering Speak: Environment and Facility Idea Note Vol.09

Lighting design creates an energy-efficient and iconic reading space

MUFG PARK Library

MEP Engineering Speak: Environment and Facility Idea Note Vol.08

Electrical work expands from lighting to data utilization and security

FUKAYA-HANAZONO Premium Outlets®

MEP Engineering Speak: Environment and Facility Idea Note Vol.07

Initiatives based on the "facilities" that support the city

Otemachi Center & Otemachi One Sub-Plant / DHC plant relocation due to redevelopment

MEP Engineering Speak: Environment and Facility Idea Note Vol.06

Contributing to the BCP of the entire town through "water independence"

Otemachi Financial City Grand Cube

MEP Engineering Speak: Environment and Facility Idea Note Vol.05

Creating a more comfortable, smarter, greener office

Kayabacho Green Building

MEP Engineering Speak: Environment and Facility Idea Note Vol.04

Delivering energy-saving air by "crawling" along the ceiling

Shinryo Shinjyo Building

MEP Engineering talk. Environment and facility idea notes Vol.03

Paving the way for radiant air conditioning using natural energy

Shinryo Shinjyo Building

MEP Engineering Speak: Environment and Facility Idea Note Vol.02

Lighting designs born from a variety of thoughts and environments

Shinryo Shinjyo Building
Full view perspective

MEP Engineering Speak: Environment and Facility Idea Note Vol.01

Even skyscrapers are ZEB Ready

(Tentative name) Uchikanda 1-chome Project
MEP Engineering designers talk. Environment and equipment idea notebook

Update : 2025.04.09

Tags

PAGE TOP