‘The World’s Greenest Furniture Company’ Uses Propane
Interior automated Green Color Factory of The Plus, Picture credit: Nicolas Tourrenc

‘The World’s Greenest Furniture Company’ Uses Propane Heat Pumps and Chillers at Its Newest Factory

Vestre’s newest factory, The Plus, uses R290 heat pumps and chillers supplied by Enrad in its production process and for heating.

Norway-based Vestre calls itself the “world’s greenest furniture company,” and part of its sustainability credentials are based on its use of propane (R290) heat pumps and chillers at its newest factory, The Plus.

Vestre has manufactured furniture for more than 70 years and makes outdoor benches, chairs, recycling bins and more using metal, wood and concrete. In 2022 it opened The Plus, which it has dubbed “the world’s most environmentally friendly furniture factory.”

The Plus is located in the town of Magnor on the Swedish border and covers 7,000m2 (75,347ft2). Vestre says the factory’s energy consumption is 60% lower than equivalent conventional factories and that its greenhouse gas emissions are 55% lower than similar buildings’.

The factory’s structure is made from wood, low-carbon concrete and recycled reinforcing steel. According to Vestre, there are 888 solar panels on the roof of The Plus, and they provide 250,000kWh of electricity annually. Vestre says heating is not needed to warm the factory until outdoor temperatures reach 5°C (41°F) thanks to its “exceptional insulation rating” and use of windows with “minimal energy loss.”

In addition to the eco-friendly building materials, solar panels and focus on insulation, propane heat pumps and chillers also help The Plus reduce its energy consumption and emissions.

“We use R290 heat pumps and chillers [made by Swedish OEM Enrad] for our daily activities,” said Lasse Nilsson, Vestre’s Quality Systems and Project Manager. “We are also looking for a high-temperature heat pump, possibly one using R600a [isobutane], for an application in our color factory where high temperatures are required.”

Nilsson and Øyvind Bjørnstad, Head of Sustainability at Vestre, spoke with Hydrocarbons21.com about The Plus and its use of propane heat pumps and chillers.

This interview has been edited for length and clarity.

Why did Vestre opt for R290 heat pumps as opposed to heat pumps using HFCs or other natural refrigerants?

Lasse Nilsson: With a strong commitment to sustainability, The Plus aims to be recognized as the world’s most environmentally friendly furniture factory. A key part of achieving our sustainability goals involves using very low GWP heat pumps, and R290 is the best solution in this case as it meets our environmental regulation standard.

Walk us through the process of implementing the R290 heat pumps at The Plus. Were there any significant challenges or obstacles you encountered?

L.N.: Initially, the plan was to implement separate heating units and chillers for the painting process, which requires heating and cooling, in addition to the distinct systems for the overall building climate control. However, during the project’s development, the potential for significant energy savings from reusing excess heat from the manufacturing process became apparent. This realization led to integrating these systems into a unified, energy-saving solution.

This integrated system now comprises two chillers that primarily generate cold water for cooling during the powder painting process. The cooling is achieved using chilled water produced by the chillers, and excess heat generated during this process is utilized and covers the heating demand in the entire building, such as floor heating, preheating of domestic hot water, radiators ventilation preheating and snow melting.

What is the capacity of the heat pump and chillers? Is there any specialty during operation?

L.N.: The system includes two chillers, each with an approximately 110kW (31.2TR) cooling capacity, and two heat pumps designed for a heating capacity of about 100kW (28.43TR).

The furniture is built with a lot of automation, and if we run out of cooling capacity from the chillers, we can also use the heat pumps as chillers. The energy needed to power the heat pumps is sourced from geothermal wells. We have drilled 17 wells, each reaching a depth of 300m (984.2ft). In the tubes inserted in the wells, a non-freezing liquid is circulated, exchanging heat with ground soil and groundwater. This geothermal heat source is utilized for the heat pumps and offers passive cooling on the cold side, enabling us to cool our offices, which makes the system more versatile.

Øyvind Bjørnstad: In the painting process, if the cooling section generates too much energy, we can store this excess by sending the warm water underground. Later, we can retrieve this stored water to create heat again.

So does that mean you use the geothermal wells as a warm water storage tank?

L.N.: Yeah, you can say that. In addition to temperature regulation, the building utilizes excess energy for practical purposes, such as heating the outdoor concrete stairs to de-ice them during winter. For situations where there’s an abundance of excess energy, we have a dry cooler equipped with fans to dissipate the remaining heat into the environment.

What safety measures and protocols were implemented to ensure the heat pumps are used safely?

L.N.: Well, each heat pump is equipped with an exhaust fan to maintain a slight under pressure inside the cabinet, enhancing safety and preventing gas accumulation. If the cabinet has any leaks or a gas leak occurs within the system, the negative pressure ensures that air flows into the cabinet rather than allowing the gas to escape outward. Additionally, gas detectors are installed within each heat pump to promptly detect any propane leaks, triggering an alarm for immediate action. Normally, these fans operate at low speeds to maintain under pressure. However, if a gas leak is detected, the fans are switched to high speed to evacuate air effectively.

Initially, there were challenges with false alarms triggered by the gas detectors, which were caused not by propane leaks but by chemical vapors released during the painting process. To resolve this issue, the gas detectors were replaced with ones better suited to differentiate between propane and other chemicals. Since this adjustment, there have been no false alarms.

Can you share any best practices for other furniture or manufacturing companies that are considering implementing natural refrigerant heat pumps?

L.N.: What truly sets our operation apart and perhaps places us in a pioneering position is the comprehensive integration of these units within our manufacturing process. This integration, especially the extensive energy recovery mechanisms we have implemented, is where we see the most value. This aspect of our system could serve as a learning model for other industries.

Also, I have some great news. We’re exploring new installations within the factory, particularly because our current use of R290 heat pumps comes with some limitations, especially concerning maximum achievable temperatures. This impacts processes that are necessary before painting, like pre-treatment washing and degreasing, that require high temperatures. These stages are currently powered by electricity, but we’re considering introducing a heat pump to this process, potentially an R600a heat pump.

Does Vestre plan to use natural refrigerants for heating/cooling at its offices or showrooms?

Ø.B.: We have an office in Oslo, but it’s rented out now. Our current office operates with a biofuel heater. As we plan to move to a new office, we are committed to considering the building’s heating and energy consumption in our decision-making process. We will ensure the use of future-proofed technology like R290 heat pumps.

“We are also looking for a high-temperature heat pump, possibly one using R600a [isobutane], for an application in our color factory where high temperatures are required.”

Lasse Nilsson, Vestre’s Quality Systems and Project Manager

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