The H&H690 manual negative pressure unit is our smallest and lightest device intended for residential renovations. Sufficient for dust control in areas smaller than 35 m² (90 m³), which allows for approximately 6 air changers per hour.Product info and a quote request
The H&H800 manual multifunctional negative pressure unit is a basic device designed for residential renovations. Intended for dust control in areas smaller than 40 m² (100 m³), which allows for approximately 6 air changers per hour.Product info and a quote request
H&H800s is a manual multifunctional air filtration device. H&H800s is an 800-model equipped with a display and an integrated digital precision pressure gauge, energy consumption gauge, and operating hours gauge.Product info and a quote request
H&H5000 manual negative pressure unit. For depressurization and dust control during residential renovations in areas smaller than 300 m² (100 m³), which allows for approximately 6 air changers per hour.Product info and a quote request
H&H5000s1 IoT automatic negative pressure unit. For depressurization and dust control during residential renovations in areas smaller than 300 m² (100 m³), which allows for approximately 6 air changers per hour.Product info and a quote request
A negative pressure unit prevents fine construction dust from spreading into other areas. Partition the area under renovation using plastic sheeting with zipper doors supported by adjustable poles. The multifunction air filtration device and negative pressure unit can be located inside or outside of the partitioned area.
In a larger space it may be impossible or impractical to partition the area and provide ventilation. In this case, it is advisable to position the device as close to the origin of the construction dust as possible.
It is often necessary to increase ventilation to speed up the drying of paint or filler or to remove solvent fumes from the working area.
The G4-rated active carbon filter available as an accessory for the negative pressure unit allows you to remove unpleasant smells from the air.
First you must decide how you are going to partition the area to be renovated. Next, calculate the volume of the space (m3). If the developer requires a specific air change rate (for example 6 times per hour), multiply the volume of the space with the ventilation rate. The resulting figure is the minimum flow rate the negative air pressure unit must be capable of producing while equipped with filters.
The practical design must consider the accumulation of dirt on the filters, the connector assemblies, and the hoses. They all increase the air flow resistance and thus the volume of air produced by the negative pressure unit. This means that negative pressure units must have redundant capacity compared to the optimum situation to ensure that sufficient ventilation can be achieved.
On sites that contain asbestos, the minimum level is -5 Pa and on sites that contain crocidolite (blue asbestos) -10 Pa. There is NO required level of negative pressure for sites where asbestos has not been found during the survey. The essential thing is to ensure that negative pressure is maintained for the entire duration of the demolition work. -1…-3 Pa is a suitable level.
The negative pressure level can be measured using a separate datalogger (GDUA), from which a negative pressure log can be downloaded on to a computer with the Meslog software. The H&H 2800S and 5000S negative pressure units automatically maintain the specified negative pressure level and allow you to download a log file on to a computer.
The best method of ensuring that the negative pressure level in the renovated area is properly maintained is to seal any leakage points, such as gaps in temporary walls, windows, and door frames, and by plugging the ventilation ducts and instructing the personnel on the proper closing of any access openings. Tip: By constructing a transitional space with a secondary opening in front of the opening used to access the renovated area allows you to minimize the loss of negative pressure while accessing the area, as each opening can be re-sealed before using the other one.
Temporary partition walls can be constructed using spring-loaded installation poles (GHDG001D) and plastic sheeting intended for construction use. All seams must be taped to seal any leakage points. However, it is necessary to provide replacement air to the area under negative pressure using a valve if the area is otherwise airtight. Excessive negative pressure can cause particles to be released from structures, makes opening doors more difficult, consumes energy unnecessarily, and may damage the temporary partition walls. Openings can be constructed in the partition walls with plastic zipper doors (2313014C).
On residential sites, the accessways must also be protected to prevent damage to floors or other existing surfaces due to traffic during construction. These areas can, for example, be protected with a 1-meter wide protective floor covering (JM16050100, a 50-meter roll). The soft, porous material on top can effectively absorb paint splashes. Placed down with the plastic film side up, the adhesive surface on the bottom side ensures that the covering remains in place.
If the renovated or partitioned space is small, it is advisable to place the negative pressure unit outside of the area. In this case you must use a connector assembly (HH80001) and a Compact accordion hose (HH12505).
If there is sufficient space, the negative pressure unit should be placed inside the renovated area. This allows you to maximize the performance.
To achieve negative pressure in the first place, the air from the negative pressure unit and the partitioned area must be directed outside or into other areas of the building. In this case, exhaust ducting provides an affordable option (H&H 800: PE12505, H&H2800, 5000: PE200015).
If the air is directed to other areas within the building, you must use G3+G4+H13 filters. If it is possible to direct the air outside, you must use at least G3+G4 filters or if the air is directed to a narrow inner yard, G3+G4+F7 filters. The H&H negative pressure units CANNOT be used without filters.
If a demolished structure was built before 1994, it is possible that the structure contains asbestos. In practice, all such sites should be subjected to an asbestos survey, based on which a safe demolishing plan can be produced. If asbestos is discovered during the survey, the demolishing work may only be carried out by a contractor with an asbestos removal license. Additional information on asbestos removal can be found in the Act on Certain Requirements Concerning Asbestos Removal Work 684/2015, the Government Decree on the Safety of Asbestos Work 789/2015, and the announcements of the Regional State Administrative Agencies.
On sites that contain asbestos, the level of negative pressure must be ≥ 5 Pa and on sites that contain crocidolite (blue asbestos) ≥ 10 Pa. The negative pressure must be monitored using a datalogger (GDUA) that produces a warning if the negative pressure is insufficient and makes it possible to review the negative pressure data during the work on a timeline. Excessive negative pressure (≥ 15 Pa) can remove harmful particles from the renovated structures, damage temporary partition walls, and make it more difficult to open doors.
Each filter, hose, and connector produces counter-pressure on the motor of the device. All of the above reduces the air volume produced by the negative pressure unit for their part. As the filters accumulate dirt, their resistance increases, and the air volume produced by the device is gradually reduced. Once the counter-pressure becomes overwhelming, the motor stops.
GDUA monitors negative pressure at the asbestos removal site, records any changes in the negative pressure, and alerts the users if a preprogrammed lower limit (for example 5 Pa) is breached with a blinking red warning light. The recording frequency of the datalogger can be adjusted from 1 second to 2 hours, and the device has enough memory for 200,000 measurements tied to a timeline. The device is programmed using the log software that can be downloaded from www.hhtuonti.fi Log information is downloaded from the device on to a computer with a USB data cable.
The counter-pressure produced by the new H&H G4, G4C, F7, and HEPA 13 filters is extremely low compared to most similar filters on the market. Low resistance filters provide more operational capacity, which means that they are more cost-effective in use.