Atmos Heating Launch Revolutionary Combinair

Atmos to launch Combinair, a low cost route to level 3 and 4 of the code for sustainable homes, at this year's Greenbuild. Atmos Heating Systems, the low carbon heating specialist, unveils the ground breaking Combinair on Stand A1 at this year's Greenbuild, 17-18 June 2009, Manchester Central (formerly GMEX), Manchester. Boasting an efficiency of 300-400%, the revolutionary Combinair integrates a condensing gas combi boiler with an air source heat pump (ASHP) into a single unit. Designed to reduce CO2 emissions the unit offers a low cost route to achieving Code Levels 3 and 4 of the Code for Sustainable Homes.

To gain Level 3 of the Code, a 25% reduction in CO2 emissions is needed, which can be achieved in a low energy house with the Combinair. This innovative ASHP combines the benefits of a heat pump with mechanical heat recovery ventilation in one unit. The Combinair draws warm air from the house mechanical extract ventilation system, together with outside air. Recovering heat from the extract air, and using only 655 Watts of electrical energy, the unit pumps up to 3kW of heat energy back into the central heating system, to achieve its amazing high efficiency. When the central heating demand exceeds 3kW, the high efficiency condensing boiler (90% Sedbuk A) cuts in to provide the extra heat demand.

Meanwhile, the weather compensating control system keeps the central heating flow temperature as low as possible, and thereby maximizes the efficiency of both the heat pump and the boiler. The system operates best with underfloor heating, but can also be used with low temperature radiators, or a combination of both. Hot water is supplied by the condensing gas combi boiler, which provides a generous 12 litres/min at 35 deg C temp rise from its 30kW power output. To achieve Level 4 of the Code, a 44% reduction in CO2 emissions is required. This can be achieved by adding the Atmos MonoSolar hot water system, which fits neatly beneath the Combinair to form a Code 4 packaged solution.

The Solar Combinair benefits from all the features and efficiency of the Combinair with the added benefit of providing 60% of the annual hot water required for an average two/three person house from a renewable heat source - the sun. "Air source heat pumps generally have a lower efficiency than ground source heat pumps, because the average seasonal air temperature is lower than the ground. However, the Combinair, takes all the warm house extract air, mixes it with the outdoor air, so that the average input air temperature is higher, resulting in a higher efficiency of 300-400% similar to a ground source heat pump," explains John Thomason, General Manager of Atmos Heating Systems".

In addition, Atmos will showcase its low carbon SolarCombi system, which can cut fuel costs and CO2 emissions by 50% compared to conventional gas heating systems. The SolarCombi presents two installation options, bringing together the Atmos MonoSolar drain-back system with either the Atmos Inter or Multi range of high efficiency condensing gas boilers. The MonoSolar features a 100 litre insulated thermal storage tank, complete with an integral copper tube heat exchanger, energy-saving variable speed pump and electronic control module, and a drain back solar collector.

Storage tank water circulates around the solar collector, absorbing heat from the sun which is transferred via the heat exchanger to the mains hot tap water to offer savings of up to 1,500 kWh of gas energy per year. The MonoSolar system includes a simple non-electric diverter valve, when the tank is above 45 deg C, the diverter valve activates to bypass the boiler and send water straight to the tap, via a thermostatic mixing valve for safety. This system reduces the boiler's operational time and hence reduces gas consumption. When the tank water is below 45 deg C the diverter valve sends the pre-heated water through the boiler to top it up to 60 deg C, or whatever the hot water temperature setting is on the boiler.

With the Inter and Multi condensing technology saving 35%, and the MonoSolar operation cutting energy consumption and costs by a further 15%, combined SolarCombi operation will save up to 50% in fuel costs, usage and related CO2 emissions. As a closed circuit system, the MonoSolar is virtually maintenance free. Because of the low volume of secondary water, and the stored hot water transfers heat through the copper pipe heat exchanger, there is no risk of legionella.

Meanwhile, because the drain back system empties the solar collector, there is no risk of overheating or freezing. Instead of an expansion vessel, the tank incorporates an air gap, and water automatically flows back into the tank's empty discharge space from the collector, eliminating the need for glycol antifreeze in the system.