Technical data

3
1.0 general
notes
The Gemini HSC range of high performance calorifiers from MHS Boilers Ltd comprises six models,
the 60-i, 100-i, 150-i, 200-i, 300-i and the 500-i providing hot water outputs of up to 1474 L/hr continuous
at a temperature rise of 50°C.
Gemini HSC calorifiers are constructed from two concentric cylindrical tanks (tank within a tank), a
principle which provides many advantages over conventional coil or tube type calorifiers.
The inner or secondary tank which contains the domestic hot water, is positioned within a mild steel
primary tank in which the primary heating water is circulated.
This arrangement ensures that the domestic water is thoroughly, efficiently and rapidly heated to
provide volume hot water for a wide variety of domestic, commercial or industrial applications.
The secondary inner tank is fabricated from corrugated stainless steel and is suspended within the
primary tank. The suspended and corrugated form allows the inner tank freedom to move and flex freely
preventing performance reducing calcium scale from adhering to the inner walls.
The corrugations also create eddy currents within the water as heating takes place preventing
stratification and ensures thorough and even heating of the entire domestic volume with no cool zones.
The thorough and even heating working principle of the HSC calorifier greatly assists with the
prevention of legionella bacteria. The scale resistant features together with the corrosion resistance of the
stainless steel significantly reduces the frequency of maintenance and avoids the need for sacrificial anodes.
Each Gemini HSC is equipped with a top mounted inspection/cleaning access port and has the facility
to be supplied with a backup electric immersion heater to provide nominal hot water supply during boiler
shutdown.
Gemini HSC calorifiers carry a five year guarantee against material or manufacturing defect in relation
to the water carrying parts. All other parts have a one year guarantee.
water byelaws scheme approved product
The Gemini HSC calorifier is listed in the Water Regulations Advisory Scheme’s Water Fittings and
Materials Directory. The Scheme’s Fittings assessment panel finds that the use of Gemini HSC fittings or
units, when correctly installed, will not contravene the requirements of the Water Regulations or
Regulations (NI).
GEMINI HSC
The water regulations ensure a good supply of wholesome water, and that only approved materials,
pipes and fittings are used to convey water.
2.0 water supply
(water fittings) regulations 1999
Building regulations are statutory and take precedence over all other regulations and recommendations.
The installation of a water heater into an unvented system must meet the requirements of Building
Regulation G3 and may only be installed by a competent person. All installations of unvented hot water
storage systems having a capacity of more than 15 litres should be notified to the relevant Local Authority
by means of building notice or by the submission of full plans. Note, it is an offence to install an unvented
hot water storage system without notifying the Local Authority.
3.0 building
regulations