Aqualia’s engineers have arguably been the most active in the field of indoor pool environmental control for over 30 years and their expertise is sought from numerous pool contractors, hotels and leisure groups, local authorities and of course domestic pool owners.

The vast majority of the schemes installed have involved the use of the Calorex Delta system and the smaller brother the Calorex Variheat. We have several hundred installations for which we can share the photographs and the case files. In the meantime we will just show off the fact that our knowledge goes beyond the supply of standard production line machines and showcase some of the specialist installations where a Calorex unit would not do the job we needed.

Will we be the cheapest? Probably not, but that is because we will not take short cuts or compromise on the quality of the installations. The Calorex Delta system includes a number of sophistications such as boiler start switching, filter pump switching (to make the best use of available recovered energy) and set back switching to revert to lower energy unoccupied mode when a pool cover is fitted. We are astonished at how often system are installed (by others) that do not use these energy saving features. What is the point of fitting a class leading heat recovery dehumidifier and then not use some of the energy saving features?

Pool dehumidifier from Aqualia
Mistral installation in a prestigeous health club with 25 metre pool complete with option for cooling.

The pool dehumidifier and air handling systems are amongst the most important parts of the equipment for an indoor pool. 

They control the room humidity and the air temperature and these two aspects ensure that the room remains comfortable and condensation free (in a building that is fit for purpose!)

The air handling system can also be one of the most energy wasteful parts of the system and this is the reasoning behind the development of the Aqualia Mistral.

Domestic pool installation with service lighting and dirty filter indictors.

The Mistral pool dehumidifier, whilst having some standard units within the range, is a custom built air handling solution that includes some of the most energy efficient technology and features of any pool air handling system on the market. That is not a boast we take lightly.

And despite that efficiency claim, we are able to design and build these units at an extremely competetive cost, especially for the large pool commercial market.

Aqualia Mistral pool dehumidifier
Domestic installation in Kensington including cooling coil and external chiller for “party mode” on a 15 metre long moving floor pool.

At the heart of the unit is a pair of the latest energy efficient EC motor fans. Not only do these permanent magnet fans offer fantastic performance at their full capacity but they also provide an unmatched level of performance adjustment.

Thus when a pool room is conditioned to perfection then the fans are turned down to the minimum required. This can reduce energy consumption by around 90% when compared with similar fixed speed fan systems.

Aqualis Mistral pool dehumidifier
Domestic installation in Theydon Bois serving a 12 metre x 6 metre pool with overflow spa

The Mistral pool dehumidifier also includes a set of fully adjustable proportionally controlled dampers. When the room humidity is acceptable then the dampers place the machine into recirculation mode, removing the input of cold fresh air with the attached energy requirement for heating.

When the humidity is high then the Mistral moves into fresh air mode, but fear not, this does not mean huge heating costs. Between the fresh air input and the warm stale air exhaust is a heat exchanger of around 80% efficiency that will recover vast amounts of heat and use it to heat the fresh air.

A dated system with low efficiency belt driven fans, poor aerodynamic design and broken controls

The efficiency of the Mistral pool dehumidifier continues with a fully proportional air heating valve and this ensures that the air is never heated any more than necessary. It does this with a valve that opens to the precise needs of the room and creates a stable fixed temperature environment, rather than the on / off undulations of the common 2 port valve fitted to most systems.

In combination with our fully proportional control output signal the Mistral can monitor the rate of temperature rise and fall of the room air and accelerate or decelerate the heating effect to great effect. Especially useful with highly glazed pool rooms with large and rapid fluctuations in solar gain.

If all that sounds a little complex to control then the computerised colour touch screen controller should allay those fears. The brains of the Mistral is monitoring all equipment and all conditions constantly and ensures that everything works in unison.

This optimises conditions and minimises running costs. The Mistral pool dehumidifier can be provided as an external weather proof unit, and can also be supplied in a multi piece assembly to ease its way into difficult plant rooms before being assembled and commissioned.

This 2022 replacement was for a 16 metre deck level domestic pool in Surrey and the existing unit didn’t offer too much scope for changes in machine dimensions. So we create an almost perfectly identical size unit but dispensed with the old inefficient belt driven centrifugal fans and installed the latest EC motor driven variable speed plug fans.

The heat exchanger installed was over double the size of the previous unit and the highly accurate temperature and humidity controls allow precise monitoring of the required fan speeds. The motorised dampers like the fans are able to respond in a precise proportional modulating manner rather than the normal “open or closed” controls of typical machines. Similarly the air heating valve operates on a proportional schedule rather than “fully open or fully closed” which means that a graph of room temperatures is a flat line, rather than the profile of a roller coaster!

With heat pump and other low temperature heat sources being favoured for their energy efficiency, you may need an air handling solution with a larger air heat exchanger to work with lower temperature heating water. These extended surface area heat exchangers are easily incorporated into the Aqualia Mistral.

More Conventional Pool Dehumidifier Systems

Calorex delta pool dehumidifier installation

Where an indoor pool can be dealt with using more conventional, off the production line equipment, then Aqualia’s design and installation team have a wealth of experience for both new built, refurbishment and simple replacement. We have worked on and installed units from Calorex, Heatstar, and all the other brands available in the UK. Our experience on the Calorex (Dantherm) range is second to none including spares holding for older machines.

Our facebook page often has up to date information on recent system installations

Our service team also keep these units ticking over at the top of their form with regular filter and belt changes and the all important calibration of controls