– What are the Benefits of Heat Recovery VRF?

Since the turn of 2020, the amount of the time we spend in indoor spaces has increased as has our need to create comfortable environments that are energy efficient.  

Variable refrigerant flow or VRF is praised globally as an air conditioning solution that is highly efficient and versatile. Similar to a multi-split system, VRF systems comprise of one outdoor unit that is connected to multiple indoor units and/or zones. However, VRF systems can achieve greater energy efficiency and comfort than a multi-split because they continually adjust the amount of refrigerant flowing to each indoor unit, giving the operator greater control over their indoor temperature. What’s more is that with VRF, it’s possible to cool and heat each room individually and even the entire floor of a building.  

What are the Different types of VRF on Offer? 

Well, there are 3 types of VRF available at Hitachi: Heat Pump, Heat Recovery and Cooling Only. Today we are not looking at all 3 types but rather we are focusing on Heat Recovery VRF. But first, it’s relatively clear what Hitachi Cooling Only VRF can offer, but what about Hitachi Heat Pump VRF and Hitachi Heat Recovery VRF? 

Though very similar in their versatility, Hitachi Heat Pump VRF is a two-pipe system that allows heating or cooling in all the indoor units but not simultaneously. This means that when cooling mode is selected, all of the indoor units connected to that system provide cooling. On the other hand, Hitachi Heat Recovery VRF systems are three-pipe systems that can provide heating to one space and cooling to another at the same time. These pipes consist of a suction gas pipe, discharge gas pipe and a liquid pipe. The additional 3rd pipe enables the system to carry the waste thermal energy of an indoor unit (produced from the main mode, whether cooling or heating) to the rest of the system. 

If you’re interested to know which type of VRF system is most suitable for your project, contact us for more information. 

How does Heat Recovery VRF work?  

Heat Recovery VRF provides simultaneous cooling and heating by transferring exhaust heat (or waste heat) from a zone being cooled to a zone that requires heating. If an office space is being cooled, the excess energy being removed is transferred into a room that requires heating. Apply this to a whole floor or even entire building and Heat Recovery type VRF increases air conditioning efficiency greatly and can lower energy usage by up to 30%, and in some cases even more.

To achieve this, a Hitachi Cooling & Heating Change Over Box or CH-Box is integrated into the Heat Recovery VRF system. CH-Boxes are made of valves that can direct the right-temperature refrigerant to the indoor unit demanding it. In other terms, the CH-Boxes help coordinate the cooling or heating as required by the indoor units. When selecting a CH-Box, low noise level in indoor spaces is a must, so our CH-Box can be located in strategic locations thanks to the piping design flexibility.  Also, their compact size means that the aesthetics and finish of indoor spaces is not impacted.  

Hitachi CH-Boxes connect the outdoor and indoor units and come as a single-port type or multi-port type, with the latter ranging from 4, 8 and 16 ports. Having a selection of single and multi-port options makes it easier to tailor each project to the specifics of the building’s architecture and layout, meaning less components for the installation and less impact on interior aesthetics.   

This shows the application of a Heat Recovery VRF system with 1 outdoor unit and 5 indoor units. Here a multi-port CH-Box lets the operator control 4 of these indoor units as individuals, meaning that these are able to offer simultaneous heating and cooling independent of each other. Though only a couple of indoor unit types are displayed in the diagram, Hitachi Heat Recovery VRF is compatible with all indoor unit types except fresh air units.

The Benefits of Heat Recovery VRF 

To fully appreciate the benefits of a Heat Recovery type VRF system, it’s best that we look at what they offer in specific applications.  

Hotels 

In a building built to meet the comfort needs of each individual, Heat Recovery VRF is an essential ingredient in providing the perfect stay.  

• No guest has the same temperature requirements, especially international hotels with guests from around the world. By utilizing a Heat Recovery VRF system, hotel management can offer guests control over their room’s climate, letting them personalize their experience.

• For example, guest in room 101 has just returned from a workout and wants to cool his room. Guest in room 102 has been working on a project all afternoon and has started to feel chilly. From the cooling in room 101, the exhaust heat can be re-used to heat room 102. This leads to two guests happy, and simultaneous heating & cooling without the extra energy expense. 

Offices 

An office consists of open-plan work spaces and various meeting rooms of differing sizes, all of which require different temperature needs depending on not only their occupancy but also orientation of the rooms. 

• With Heat Recovery VRF, offices that have south and north facing rooms can balance out the distribution of heating and cooling needs by transferring the excess energy from one side to the other. 

• This type of system promotes higher energy efficient ratings, contributing to a green building certification.

• For a project that is designed for a small server rooms that needs year-round cooling even during Winter, the Heat Recovery system can be fitted with a cooling-only indoor unit, which means that a CH-Box isn’t required, sparing the need to install extra dedicated cooling equipment.  

Simultaneous cooling and heating systems are also beneficial for residential usage, especially in locations where the climate is not extreme but mid-season temperatures can rapidly alternate, creating the demand for either cooling or heating depending on the amount of sunlight or the number of people in a room. However, it is in business and industry applications that Heat Recovery VRF proves itself to be one of the most efficient means of providing excellent heating and cooling and comfort. 

What’s more is that with our centralized control solution, Central Station, with give building and facility managers the tools required to monitor and adjust 360-degree control of a building’s climate. Read more about the Air Conditioning Controllers offered by Hitachi Cooling & Heating, here.  

If you´re interested in learning more about our VRF product range, click here, or if you would like to learn more about how Heat Recovery VRF and your business, please select your region's page and contact us.