Altecnic ‘broke the mould’ when it released its electronically controlled SATK30 series heat interface unit (HIU) 6 years ago. Now, with the release of the new generation SATK32 series, we have a HIU that can protect the network from failure and inefficiency.

Primary flow rate limitation:

Typical UK apartments have a heating demand around 3 to 4 kW. However, for the first 10 – 15 minutes of the heating coming on, the apartment can take 8 or 9kW from the network. If lots of apartments are on heating at the same time, say at 7:00am on a weekday morning, then the network may not have enough capacity and it will fail to provide hot water at the extremities. The SATK32 range has the facility for the maximum flow rate the HIU can take from the network set. A HIU connected to a 3kW apartment can only take 3kW, nothing more. The network is protected from failure and the network demand peaks are reduced.

Return temperature limitation:

The low heating demand in today’s apartments mean that only a very small flow rate is required on the heating circuit. This low flow rate makes it very difficult to balance the radiators in an apartment. The result is that most apartment heating systems are not balanced correctly. If the circuit isn’t balanced, then the return temperature will be high. This high return temperature will be transferred to the network and the efficiency of the whole network will be greatly reduced. The SATK32 is equipped with Return temperature limitation (RTL). This feature allows you to set a maximum return temperature on the network. Once enabled and set, the HIU will control its output into the apartment to ensure that this pre-set, primary return temperature is met. The network is again protected from inefficiency and failure caused by small delta T’s and high primary flow rates.

Preheat control:

Many HIU’s on the market have a permanent, in built preheat function. This bleeds energy through the HIU constantly 24 hours a day. Bearing in mind that the tenant may only use their hot water a few times a day, having preheat on permanently makes no sense and costs the tenant money. The configurable controller supplied with the SATK32 can be set to allow the tenant to set the preheat function like his heating system to come on and go off automatically only when he needs it.

Modbus output:

The SATK32 range has full Modbus output/input. This means that the HIU can be set up and commissioned remotely. Any faults or error message on the HIU can also be read remotely. If a tenant believes there’s a fault with the HIU, the HIU can be interrogated remotely and the fault diagnosed prior to any attendance on site. The engineer can then ensure that he has the spare parts required prior to any attendance on site. Even the actual temperature within the apartment can be checked to see if it is at the set point set on the HIU.
The drive to make buildings ‘Smart’ continues apace and there are now specific companies that specialise in the operation and running of these smart buildings. The Modbus output from the HIU removes much of the hardware that needs to be installed on a smart network and therefore cost. The Modbus allows more accurate network control based on demand and the HIU facilitates a much more efficient network.

Weather compensation:

Another feature of the HIU is the weather compensation option. The HIU has the ability to vary the heating output based on outside temperature. It’s a standard option on the SATK32.

Prepayment compatibility:

The SATK32 is compatible with all the prepayment units/systems on the market. The prepayment unit is simply wired into the HIU controller and when the tenant runs out of credit, the HIU will close down the heating and DHW output without the need for a separate motorised prepayment valve. This not only saves money but allows for prepayment to be retrospectively installed without the need for any plumbing work.

Clamshell insulation:

To reduce heat losses to an absolute minimum, the SATK32 has full clamshell insulation. Once the cover is fitted to the HIU all the internal components are completely encapsulated in insulation. Heat loss from the unit is negligible further reducing costs to the tenant.

A full range of accessories are available for the SATK32 range including integral energy meters, prepayment systems, flushing bypass valves, ball valve kits, first fix rails etc. Altecnic can also give advice on energy centre sizing, primary network design, diversity application and network flow rate calculations. We also have a CIBSE approved CPD seminar that can be presented at your offices should this be of interest.