Large Heating Savings from Chilled Beams

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All,

I am getting unusually high heating energy savings, ~50%, when I apply chilled beams (induction units) to patient rooms in a hospital.

I just stumbled across another energy report written by another firm for a laboratory project of ours that shows the same results, ~50% heating energy savings when applying chilled beams.

The cooling and electricity savings are in line with what would be considered reasonable and I realize there should be some heating savings due to a reduced reheat load, but 50% seems excessive.

Both buildings have approximately 40% of the floor area using chilled beams.

The lab is in a cold climate, the hospital is in a more temperate climate.

Has anyone else come across this issue?

Thanks,

FRED BETZ? PhD., LEED AP

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It possible. Reheat can be a really large load - I've seen labs where 50% of the energy usage was reheat (in Summer).

In most labs, the hot labs control the supply air temperature and the ventilation driven labs end up using a LOT of reheat energy. Chilled beams are really a strategy to reduce reheat loads by allowing you to reset your supply air temperature.

A good sanity check is to submeter the reheat coils. This is easier to do if its electric or attached to a campus steam/hot water system. If it's a boiler I would create a separate boiler for the reheat coils (just for diagnosis).

You could attach your inp file too.

Vikram Sami, LEED AP

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