Luft­technik Schmeißer (LTS) from Berlin has been working on the formula for fresh and healthy indoor air for a long time. The family-owned company, which has been in busi­ness since 1903, devel­oped air heating as early as 1945, before launching the first motor-driven venti­lation system in 1983. In 2019, the company finally decided to upgrade its TSL-150 decen­tral­ized venti­lation unit and looked for suit­able compo­nents at ISH trade fair. “Our build­ings are becoming increas­ingly dense and require high-perfor­mance venti­lation systems. These in turn have to run more and more effi­ciently. This is why we wanted to give our TSL-150 an upgrade – to keep pace with the times,” explains Sebas­tian Scholz, third-gener­a­tion managing director at LTS.

Complete solu­tion for conve­nience

ebm-papst, with whom Schmeißer has been working since 1993, presented the EC centrifugal fan RadiCal in a scroll housing at ISH. Its features won LTS over imme­di­ately. “The fan has a great set of stats and also has every­thing we need in terms of sensors. On top of that, it’s easy to connect,” explains Sebas­tian Scholz.

The RadiCal in a scroll housing won LTS over imme­di­ately. (Photo | ebm-papst)

Nikolai Lukin, Team Leader Resi­den­tial Venti­lation at ebm-papst, adds: “When further devel­oping the RadiCal, our main focus was on effi­ciency and volume consis­tency. We can only achieve this using sensor tech­nology – which is why we devel­oped the scroll housing and now offer our customers a plug-and-play system solu­tion.”

The inte­grated anemometer measures the air flow, and the elec­tronics regu­late it to an accu­racy of about one percent. The built-in sensors for humidity and temper­a­ture make it possible to control the fan as needed. “With it, we are now 30 percent more effi­cient and 3.5 dB (A) quieter than with compa­rable centrifugal blowers,” says Scholz. It wasn’t just the inte­grated sensors and improved figures that were crucial to him and his team: “Its MODBUS inter­face allows us to easily read out the values, even remotely, or connect addi­tional sensors like a CO₂ meter if needed. That’s state of the art.”

New concept – more possi­bil­i­ties

The opti­mized design and extended range of func­tions meant that it no longer made sense to install the venti­lation system in existing types of unit; a completely new one was needed. The result was the TSL-152: a decen­tral­ized venti­lation unit incor­po­rating two RadiCal in a scroll housing and achieving a rated air flow of 125 cubic meters per hour. “We pulled out all the stops in terms of design,” says Scholz. This is because the new venti­lation unit is designed to cater primarily to indi­vidual rooms in multi-story build­ings such as hotel rooms or smaller apart­ments, which makes instal­la­tion partic­u­larly tricky.

For the TSL-125 we pulled out all the stops in terms of design.Sebas­tian Scholz, Managing Director at Luft­technik Schmeißer

For example, there is a maximum height of 30 centime­ters avail­able for the unit in the false ceiling. The TSL-152 fits right in at 28 centime­ters. This is also due to a special foam forming the new base for the self-supporting housing, which is replacing the old aluminum-based one. This saves weight, space, and enables greater quan­ti­ties to be produced. “The new design was also impor­tant because we didn’t want to compro­mise on air filtra­tion, heat recovery or humidity control,” explains Christoph Stein, design expert at Schmeißer. As a result, the venti­lation system achieves an effi­cient 86 percent heat recovery, and 76 percent mois­ture recovery. It also filters minute parti­cles such as fine dust, viruses and bacteria in outdoor air to at least 55 percent in accor­dance with filter class ePM1. “If neces­sary, however, you can also go up a notch here.”

The new venti­lation unit is ideal for intel­li­gent single-room control in small apart­ments or for hotel rooms and class­rooms. (Photo | Luft­technik Schmeißer GmbH)

Venti­lation and heating

Another feature makes the venti­lation system the first combi­na­tion unit at Luft­technik Schmeißer: “As an option, we can also connect a heating coil to the TSL-152 and replace other heating systems. This makes both the supply and the billing over sepa­rate elec­trical circuits much simpler,” explains Sebas­tian Scholz. Effi­ciency also has to be right for all the func­tions. “With a device that runs almost contin­u­ously, such as a venti­lation system, it does make a differ­ence whether the device runs at well over 50 kilo­watts an hour, or only 36 like the TSL-152. In addi­tion, the sensor tech­nology in the RadiCal ensures that the system is opti­mized for demand, making it even more econom­ical on the bottom line.”

As an option, a heating coil can also be connected to the TSL-125. (Graphic | Luft­technik Schmeißer GmbH)

Sustain­ability taken to its logical conclu­sion

During the two-year devel­op­ment of the TSL-152, the compa­nies were in regular contact with each other. “The support was excel­lent,” says Scholz. Luft­technik Schmeißer is one of the first compa­nies to use this new devel­op­ment from ebm-papst in series produc­tion.

LTS has also given thought to pack­aging. “If you think about the number of units in a hotel or resi­den­tial building that all have to be indi­vid­u­ally pack­aged, you can imagine the amount of special pack­aging waste like styro­foam,” notes Christoph Stein. “We have suffi­cient confi­dence in the stability of our product. So our ‘slim pack­aging concept’ was created, consisting only of card­board box and a bag made of recy­clable PE plastic, which is also intended to serve as tempo­rary protec­tion against construc­tion dust once the venti­lation unit is installed in the ceiling by simply being slipped over the unit from below.”

Jens Duchow, regional manager and contact person for LTS at ebm-papst adds: “We are very pleased that Luft­technik Schmeißer is on the same wave­length as us when it comes to sustain­ability and effi­ciency.” Schmeißer has already used the inno­v­a­tive all-round concept for various customers such as a school and a motel. “We want to move more into multi-story build­ings. They’re becoming increas­ingly impor­tant, and that’s exactly what our device is designed for.”