Realizing the Potential of Data Center Waste Heat Reuse

IT equipment generates a lot of heat, and data centers consume a lot of energy keeping that equipment cool. Effective thermal management is critical to the reliable operation of the data center, but that doesn’t mean heat has to be exhausted as waste. Some data centers are reusing heat instead.

Think about it. In the cooler months, we use energy to heat our homes, offices, and other buildings. Why not take advantage of the heat from data centers?

Data center heat reuse is seeing growing interest amid mandates to reduce energy consumption and work toward “net zero” emissions. Operators are finding that heat reuse programs can help them reach their sustainability goals at the macro level. Rerouting heat to nearby buildings can enable those facilities to reduce their energy consumption. It also saves money through greater energy efficiency.

Data Center Heat Reuse Opportunities

Some data centers exhaust heat into the atmosphere. Others route heat into a plenum, where it is drawn into a computer room air conditioning (CRAC) unit or the air handling unit of a water-cooled system. The air is chilled and returned to the data center.

In a water-cooled system, the temperature of the water rises to about 77 degrees Fahrenheit (25 degrees Celsius) as it cools the data center air. That water can be condensed by heat pumps to 158 degrees F or more and piped to heating systems in other locations. Since 2019, Amazon has used heat from its Westin Building Exchange data center to heat its Seattle headquarters.

Here are two other examples of how this concept can be applied.

Heating Other Buildings in the Community

Data center heat reuse works best when applied to facilities with high heat demand and communities with district heating systems. For example, Amazon’s Tallaght data center heats residences, two hospitals, and Technological University Dublin. Meta’s data center in Odense, Denmark, heats thousands of local homes. 

Agriculture and Aquaculture Applications 

Unlike facilities occupied by humans, greenhouses need consistent heat year-round. Data center heat reuse offers an alternative to geothermal energy, which can contaminate groundwater and reduce water tables. Heat from data centers can also heat the water used to breed and raise fish commercially.

Obstacles to Data Center Heat Reuse

Moving heat from one place to another isn’t as easy as it might sound. Here are some of the obstacles to data center heat reuse.

Heat Lost in the Transfer Process

Heat loss occurs when the liquid in pipes is hotter than the surrounding air. Data centers must monitor the heat being transmitted to ensure it works effectively at its destination. Generally, data centers have to install heat pumps to get the water hot enough to support distant heating systems.

Distance from the Destination

A related problem is the distance the heated water must travel to its destination. If the data center is too far from a district heating system or other point of consumption, maintaining the water's temperature won’t be feasible. Similarly, the effort will be wasted if there aren’t enough consumers to take advantage of the recycled heat. 

Infrastructure Requirements

Data center heat reuse requires significant infrastructure investments to achieve the necessary scale. The technology is new, so it tends to be expensive. As the concept catches on among more data centers, the cost will likely decrease. In the meantime, tax credits, government investment, and cost savings can help data centers offset some of the startup expenses.

Heat Reuse and Local Goodwill

Data center markets are no longer concentrated in select regions across the country. The rise of distributed computing, coupled with power and land constraints, has forced developers to explore markets of all sizes across the country. The challenge is public perception. Communities worry about data centers taking more than they give in the form of power, water, land, and more. Companies can build goodwill from local governments and communities by demonstrating their commitment to offsetting their consumption with practices such as heat reuse. 

Heat reuse opportunity should be a location consideration for new data center developments. After all, data centers exist to empower digital communities; why not extend that thought to the physical world as well?

Enconnex: Your Global Data Center Partner

Enconnex has achieved ISO 14001 certification, showing our commitment to energy efficiency and environmental sustainability. We have various products and solutions to help data centers meet their sustainability objectives. Contact one of our specialists to learn more.