What is VWART?

VWART stands for Volume Weighted Average Return Temperature. The temperature calculated is that being circulated back to the network from the Heat Interface Unit (HIU). In the latest BESA Test Regime, the VWART is calculated across both heating and hot water modes over an annual usage period. This measure providing a reasonable estimate for the impact of the tested HIU on the performance of the heat network. Generally, the lower the return temperature back to the central plant, the more efficiently the network can operate.

Take a look at Baxi's AquaHeat HIU 

For homes fed with heat from a heat network, the Baxi AquaHeat is the answer to your apartment’s heating and hot water requirements. Perfectly suited to supply heat to communal and commercial premises in your development.

Related FAQs

Heat Interface Unit (HIU) pros and cons

Find the pros and cons of Heat Interface Units (HIUs) here at Baxi FAQs.

How to reset pressure on my Heat Interface Unit (HIU)? 

Watch this video to find out how to reset pressure on my Heat Interface Unit (HIU)...

What is the price of a HIU (Heat Interface Unit)?

Average cost for a Heat Interface Unit (HIU) can be from around £800 to £1500, depending on the HIU type, performance of the unit and equipment provided.

What support is available in the design of my Heat Interface Unit (HIU) system?

Our Application Engineers can assist in advising clearances, dimensions, and possible locations for consideration. Find out more...

What support is available for installation / set up of the Heat Interface Unit (HIU)?

Baxi’s technical helpline supports you at every step of your installation & commissioning process. Find out more about training & enhanced warranty here.

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