Published 2022-08-11

Operation technician Martin Lundin works with the indoor climate at the hospital in Västerås but also at the hospitals in Fagersta, Sala and Köping in Region Västmanland. His constant challenge is to create comfortable indoor environments for both healthcare professionals and patients while keeping energy consumption low.

To help him in his daily work, Martin Lundin often uses the smart multi-instrument testo 400. Nordtec caught up with Martin to hear about his impressions and experiences with this climate meter.

Can you tell us a bit about your work?
– I do everything in the field of indoor climate and check ventilation flows and also perform some minor adjustments. However, as we have about 400 000 square meters to cover in our premises, much of this work is done by hired contractors.

– I am also an energy coordinator. In this role, I work actively to reduce energy consumption, which is measured in kilowatt hours per square meter.

– Also, you should not feel that there are temperature differences between different hospital departments, but it can be difficult to find that balance. However, the instrument is great for walking around and measuring temperatures and also differential pressure between different corridors, i.e., the air conditioning system. over- or under-pressure to ensure the right balance of ventilation systems.

– I also work on preventive maintenance. To enable my staff to easily troubleshoot when we have problems with heating or ventilation, I have equipped them with a bag containing the testo 440 multi-instrument and various accessories. Good work always requires good instruments and tools.

Do you measure both in premises and ventilation ducts?
– Yes, exactly. I measure temperature, humidity and airflow in ducts and premises. When measuring flow in canals, I sometimes have to drill a hole and measure at several points in a cross section of the canal area.

You mean so-called grid measurement?
– Yes, that’s right. That’s where the instrument is fantastic. You specify whether it is a square channel, for example, enter the dimensions and then take a number of measurement points. The instrument then automatically calculates the airflow.

Are you satisfied with the instrument?
– I’m super happy. I had a testo 440 dP before, but needed an instrument with better pressure measurement accuracy and the ability to log trends. There are so many more possibilities with the testo 400.

Do you feel unfamiliar with a touch screen on a measuring instrument?
– No, given today’s technology and how accustomed we are to mobile phones, it was quite natural. On the contrary, it was very easy to get started with the testo 400.

How do you analyze the measurement results?
– I usually connect the instrument to the computer and use the program testo DataControl to analyze the values. Then I get reports that are very useful where I can also attach pictures. I think that’s really good.

Can you tell us about a particularly interesting measurement mission?
– Yes, in Sala hospital we changed the control equipment on an old unit to get better control of the supply air temperature. But initially there was too much alternation between high and low temperatures.

– Then we were able to use the 400, because we could connect both before and after the heating coil. The controller’s P and I times were changed and we could continuously see how it calmed down or if the values jumped. You could see when it started to oscillate. That’s where the trend management in testo 400 is fantastic.

– Then I am currently working on mapping the indoor temperatures of the entire hospital, in all departments at different outdoor temperatures.

That sounds like a big job?
– Yes, our client requires that energy consumption be reduced, so we have a huge job ahead of us to get the right curves, especially on the heating side and to have the right temperature in the supply air.

What did you use before getting the testo 400?
– Previously, as I said, I had a testo 440. But I needed better accuracy of the differential pressure measurement at low air flows. Also, I like to see trends, which cannot be done in the same way with this instrument.

What kind of sensors do you use?
– I have a small hot wire sensor that is always in the instrument. Then I have a digital sensor that measures both moisture and temperature. These values are transmitted to the instrument via Bluetooth. Both these sensors also work with the old testo 440. Then I have a clamp-on sensor for pipe temperature measurement as well.

What did you use before getting the testo 400?
– Previously, as I said, I had a testo 440. But I needed better accuracy of the differential pressure measurement at low air flows. Also, I like to see trends, which cannot be done in the same way with this instrument.

Have you needed support from us to get started?
– No, I think it has worked well. The only thing that happened was that the pipe temperature sensor broke on one occasion.

Do you also use data loggers to see trends over time?
– Yes, I do if I am unsure and there are major problems that are not immediately apparent. Then I have to log for a longer period of time and analyze the anomalous trends afterwards.

Do you have any requests, anything you would like to see in the instrument?

– I don’t know… I haven’t used exactly all the features yet, but right now I’m just very happy with the instrument!

– If one could wish freely, it would have been good to have a socket at the top of the front for a hot wire sensor. He often holds the instrument upside down.

– Then it would be good if you could make a few more pre-settings in the instrument via the analysis program testo DataControl.

Published 2022-08-10

Almost ten years ago, Johannes Öberg switched from being a shop salesman to a service technician in ventilation. He hasn’t regretted it for a second. We caught up with Johannes to talk about the varied challenges of the job, ‘airborne’ and his love of testo 400.

– I like this job because no two days are the same. “There are always different conditions and challenges that must be solved to ensure good ventilation and a comfortable indoor climate,” says Johannes Öberg, who is currently a ventilation technician at Bravida.

An example of this is when Johannes and his colleagues were hired to review the ventilation system of a tire company. The unit was old, but even old units can last for many years. If they are maintained at regular intervals, that is. This unit had received minimal love over the past eight years.

“The air did not get through”
– One of the fans tripped because of the overheating protection and we had to do an extensive cleaning and filter replacement. They were so dirty that the filter bags had started to come off the frame. The air was simply not getting through. ‘It was like trying to draw air through a plywood sheet,’ Johannes recalls and continues:

– Of course, it took some time to fix everything. And time, as we all know, is money. But the people working there have to have air and that unit hadn’t delivered any air for years. It had just stood and walked with a single working fan.

This is what Johannes likes about his job. He enjoys tackling something that is a bit tricky, thinking about it a few times and then coming up with a solution. It is far from easy all the time, because every site is different. From belt-driven fan systems from the early 1970s to the very latest advanced ventilation systems with different layers of control systems.

Factors affecting air quality
Johannes and his colleagues are often called out on emergency missions. Often the complaint is that it is too hot in a room. While it may be that the ventilation system is not doing its job, it is remarkably often the case that other factors affect the perceived air quality.

– One room may have been converted into a conference room and more people are staying there than before, which affects the air. It can also be about a light source that makes the room warm. Sometimes it’s a bit difficult to determine whether it’s hot air or stuffy air. If it’s just stuffy air, it often means that we have to fix the ventilation. But if it is too hot, it is more likely to be due to the cooling or heating system.

A common ‘air villain’ is dust. Air ducts that have not been cleaned for a long time can accumulate up to one centimeter of dust, which reduces the diameter of the pipes quite significantly. This creates annoying additional noise and also results in lower air flows.

“The pipes are roaring”
When we meet Johannes, he and his colleagues are busy finishing the rebuilding of the ventilation system in the roofing company Wicote’s premises in Arendal, just outside Gothenburg.

It is a relatively old facility that has looked the same for many years, even though the premises have been redesigned several times to suit different tenants. The challenge was to find a good ventilation solution without rebuilding everything. There is nothing wrong with the unit and the airflow is there. Instead, it has involved, for example, adding supply air ducts where necessary.

– There is noise in the pipes, which is a sign that the unit is running too hard and pushing out too much air. During the adjustment, we will open all the valves fully and measure the total flow.

– By adding up all the sub-flows, we know that it should be a total of 330 liters. We put the aggregate at about ten percent above that to have a bit more to work with. We will then go around measuring and adjusting the devices, and then turn down the fans if necessary.

You use testo 400 exclusively, why?
– For several years I have used almost exclusively Testo instruments. This is largely because several other manufacturers have designs and user interfaces that feel very dated.

– One thing I like about the testo 400, for example, is when measuring with hot wire in a channel. The graph then guides me through the measurement. “If I set up twelve measuring points, for example, the meter tells me to insert the probe nine millimeters into this borehole, it then registers the result and I can move on to the next measuring point,” says Johannes, who points to the instrument’s large touch screen and then adds:

– The 400 is also particularly good if you are measuring a duct that has a touch screen. Then you just hold the hot wire sensor against the cover to measure.

Easy for everyone to use
Johannes points out several times that he appreciates the simplicity of the testo 400. Since he uses the instrument daily, he has quickly learned how it works. But it works just as well if a colleague needs to borrow it to measure the flow in a channel, for example.

– We have compared and seen that it works without problems. I have first made a measurement, handed the instrument to a colleague who made his own measurement and then compared the results. Especially hot wire measurement is very sensitive, because if you tilt the sensor towards the air stream a little bit, you get a completely different value. But by being guided through the measurement, both I and my colleagues got the same results.

– The instrument is a great help for those who are reasonably experienced and fantastic for those who are less experienced.

Create and send reports
The instrument’s built-in camera and report function is something that Johannes really likes and uses a lot.

– It’s great to be able to create detailed, attractive reports directly in the tool and then email them to customers. With the built-in camera, I can take pictures that show, for example, the position of the damper during the measurement. It shows which sensor was used and the differential pressure and airflow.

In addition to attaching pictures, there is the possibility for Johannes to easily enter text explaining what he has done, thus avoiding discussions about the number of working hours and costs for e.g. service with filter replacement. Johannes Öberg believes that it is this simplicity and all the smart functions that make the testo 400 an extraordinary measuring instrument.