The HEM-SL range of heat exchange modules is based upon similar technology of our standard NVx range of suspended unit heaters. HEM-SL units have been adapted to suit the needs of O.E.M’s by the provision of its slot-in casing arrangement. It has been specifically designed with Air Handling Manufactures in mind. It’s low resistance to airflow and ability to have combination units make it flexible for both selection and usage.
The HEM SL ranges from 30-200kW 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 SL modules are of similar configuration to NVx but are of two-pass design to minimise the majority of module widths to an impressive 400 mm.
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 SL 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.
HEM-NVx heaters are based on aluminised or T409 stainless steel tube heat exchange elements with each tube having a dedicated inshot type burner and a closed combustion circuit that is fan assisted with fully automatic controls. Units are available as on/off, high-low or fully modulating, with a low fire rate of 40%. Each unit is fitted with a condense drain and solenoid valve and supplied without controls housing for installation into air handling units.
- T316 stainless steel tube upgrade
- High-low burner option
- Modulating burner option
- Burner enclosure - room sealed option
- Burner enclosure - fully weatherproofed
- Multi-stack unit option available
- Air bypass facility available
- Vertical or Horizontal flue assembly
- 10kW to 200kW outputs