The HEM NVX ranges from 10-200kW heat outputs, Where higher duties are required modules may be installed in either parallel or in series. Depending on model and size such multiple modules may be supplied factory pre-assembled. Fuel usage and emissions are a key consideration within the HEM design with all modules offering an efficiency of 90% at nominal airflow rates.
Controllability is a key benefit of HEM modules. Each individual module can be specified in on/off, high/low or modulating burner format. High/low and modulating burners provide a turn-down ratio of between 2:1 and 4:1 depending upon model selection. The application of multiple modules further enhances the ability to increase turn-down rates and control heat output to close tolerance. A feature of HEM tubular heat exchangers is their ability to provide efficient heat transfer with minimal pressure loss across the tube bank, thereby allowing designers to optimise fan selections. For applications with high airflows it is possible to provide bypass facilities.
Typically modules are arranged for internal installation, often fitted within the confines of the air handling unit. External units can be supplied with fully weatherproofed burner enclosures. Room sealed enclosures are also available allowing the connection of ducted combustion air as well as access to the flue spigot.HEM NVX modules utilise proven tube technology four pass heat exchangers with each tube being fired by a dedicated, matched and efficient in-shot burner.
Efficiency and ErP Compliance
From 1st January 2018 all warm air heaters used to provide comfort for the occupants of a heated space are required to meet minimum standards of ‘seasonal’ efficiency as determined by the Ecodesign regulation (EU) 2015/1188, Directive 2009/125/EC - Lot 21 Tier 1. Compliance to the standard is mandatory. HEM NVx heaters placed on the market after 1st January 2018 comply with the requirements of the standard.
- Wide range of outputs, featuring a multi-unit capability (individual units can be configured together to operate in series or parallel to provide higher outputs.
- Slimline width - no requirement for inlet or outlet transition sections reducing material and labour costs for OEMs plus reduced length of the air handling unit.
- Easy to service - multi-tube burners fed from a manifold with a single gas safety control.
- Suitable for retro fit/upgrade - HEM-NVx is ideal for the conversion of hot water, steam or electric systems to gas.