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Hydronic Heating & Cooling
Industrial & Commercial

Hydronic Unit Heaters


Sigma horizontal and vertical propeller unit heaters feature a wide performance range for both hot water and steam applications. The performance range is consolidated to reduce the number of different models, simplifying the selection, ordering and installation activities.

All single-phase models may be ordered with a low-cost speed-reducer permitting units to be field tuned. Side entry coil connections on model H units permit installation in clearance-critical low ceiling environments. Special coils, constructed with 0.032” wall Cu-Ni tubes or 0.049” wall copper, are available for more demanding applications. Furthermore, special explosion-proof motors may be ordered for any unit size.


All units are designed for maximum airflow and for optimum air distribution. As a result, outlet temperatures are reduced, avoiding unwanted “hot spots”.

Standard units in both horizontal (model H) and vertical configurations (model V) have 12 fpi fin series for enhanced performance.

All model H units are equipped with horizontal louvres for simple vertical air distribution adjustment. Optional Louvre Fin Diffusers on model H units permit enhanced air distribution adjustment with either a wide spread of warmth or focussed warm air for greater unit throw. Optional Louvre Cone Diffusers are available on model V units to permit tailored airflow distribution.

Need something special?

We do custom manufacturing to nearly any specification. Get in touch to discuss your job with one of our engineers.

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