Should I use a vacuum cleaner or negative air unit to extract the dirt?QuestionShould I use a vacuum cleaner or negative air unit to extract the dust which has been dislodged from the duct surface by brushes or compressed air?
AnswerThe answer is: you should use neither. You should use a specifically designed duct cleaning extractor system which will extend your 'reach' into the duct system. This is very important since most of the labour time is taken up in fitting the extractor to the duct system. So the fewer 'hook-ups' you can do, the more productive you'll be. That is: you want to 'pull' the maximum amount of ductwork at a time.
A proper extractor is a balance of high air volume to make the duct-laden air move quickly enough in the duct, and high static pressure to overcome the resistance of the duct system
Vacuum cleaners are the wrong solution because the have very high (negative) static pressure, or vacuum, but they move hardly any air volume. That's why you can have a vacuum cleaner head just a few centimeters away from your face and you'll feel no air movement.
'Negative air' units are a technology borrowed from the asbestos removal industry and are designed to simply keep an under-pressure in a containment tent. There's not enough static pressure to pull against the resistance of a duct system, so it soon runs out of capability.
Video recordingQuestionHow can I record duct video inspections (or cleaning and/or spray-coating with the TDB robot)?
Answer
We offer LCD screens, which are robust and simple methods of viewing what you’re looking at with the video cameras (Minicam, Inspector or TDB Robot), but it does not record.
To record, we would recommend a camcorder or a multimedia unit/ tablet such as the Archos 7 with a DVR station. It is important that whatever method you use is capable of receiving an analogue video signal, direct off the camera. About 30% of camcorders are so capable (e.g. many Canon) and the Archos with DVR.
It is possible to use ‘video-grabber’ hardware and software and feed to a laptop, but I wouldn’t recommend it because the PC needs to be super-quick, and you have the awkwardness of operating a computer on site and moving from place to place.
HVAC System TrainingQuestionWhere can I learn more about HVAC Systems?
AnswerThere is an excellent introduction to the various types of heating Ventilating and Air Condiditioning (HVAC) systems in a Center for Disease Control document, which you can download from the NIOSH section of their website.
Have a look also at the article in the Duct Discussion/blog. If you have any trouble downloading the pdf, contact us and we'll send you a copy.
Triventek offers individualised training and consultancy in custom packages to substantial buyers of Triventek duct cleaning equipment, along with more specific HVAC hygiene technical and commercial training, business start-up etc. This can cover technical and commercial questions and is based on 29 years experience in the duct cleaning industry
Video connectionsQuestionHow do I connect my Minicam (or Inspector, or TDB Robot) to an Archos or other media player/recorder?
AnswerThe important thing to note is that the signal out from Triventek video cameras is an analogue signal via a BNC plug.
Go to any radio spares/electronics/electrical goods retail shop and buy a female BNC to female phono adaptor
You can then use the phono video cable supplied with the Archos unit to connect into the DVR (Gen 5) or Travel Adaptor (Gen 4) supplied as an optional extra with an Archos unit.
Likewise for a camcorder, all you need to do is to ensure that the it can receive analogue video, and you may need an adaptor plug from the male BNC plug on the Triventek equipment.
Biocidal Duct CoatingQuestionShould I use a biocidal coating in ductwork?
AnswerThere is some debate about the use of continuously active disinfection in HVAC duct systems.
There is concern at the idea of having a continuous biocidal activity in an airstream. Basically: you don’t want to have a ‘medicine that is worse than the disease’.
Basically our view is that systems should be kept reasonably (particulate) clean.
Biocides may be used for disinfection as a one-off treatment, where necessary. In this case, we would recommend a chemical such as stabilized chlorine dioxide precisely because it quickly degrades to non-active materials and so can pose no ongoing threat to the airstream.
Support for this view can be found in various places e.g.:
· University of California Environmental Health & Safety
· Chartered Institute of Building Services Engineers: TM26 ‘Hygienic Maintenance of Office Ventilation Systems’
· WHO GUIDELINES FOR INDOOR AIR QUALITY: DAMPNESS AND MOULD 2009, pp50
· HVCA Guide to Good Practice TR19: Internal Cleanliness of Ventilation Systems
At parts of the HVAC which suffer from trapped, non-refreshed water accumulation, e.g. incorrectly designed fitted condensate drain trays, then the hazard associated with microbiological colonisation is much greater. In these circumstances ongoing biocidal treatment, e.g. with Triventek BioBlocks can be justified (if it is not reasonably practicable to take engineering measures to deal with the problem) on a risk-benefit basis.
Compressed air equipmentQuestionWhat is the difference between the various types of compressed air equipment?
Answer1. All the compressed air equipment, except the ST80140805 and ST80140810 small guns, must have high-volume compressed air at approx 7 bar. High-volume means 5.5 m3/min -12 m3/min. This is essential to get the nozzle to ‘stick’ to the duct surface. Please be sure that you have such volume available (typically to a maximum separation of 90 m from compressor to cleaning tool)
2. The 12mm Tornado nozzle ST80101012 is the basic workhorse, with the greatest flexibility
3. The 25mm Tornado Nozzle ST80101025 is better for larger ducts, but a little less flexible
4. The 12mm and 20mm ST80100012 and ST80100020 rotating brush nozzles combine the ‘stickability’ and flexibility of a compressed air nozzle with the scouring effect of a steel brush rotating at 11,000 rpm. They work only on round ductwork, and are excellent for typical industrial and slightly damp/sticky/well-adhered industrial and other extract duct deposits
5. The ST80100025 Rotating Whipstream Nozzle is different from all the others as it does NOT stick to the duct surface, but rather centres itself in riser ducts and shoots out a concentrated pulse of air up to 1000mm distant. This means you can clean risers in one hit, without multiple access on every floor. You can work upwards or downwards. It can also be attached to the TDB multi-platform robot for use in difficult and larger horizontal ductwork where man-entry is undesirable.
6. The ST80140805 and ST80140810 small guns have semi-flexible hoses which can be bent to shape, and are typically used for ‘final few metres’ cleaning with either forward, or rearward-facing nozzle jets. They need only 50-80 litres/min compressed air. They can be conveniently fed by the compressed air manifold with quick-release connections (and ¾” clamp connections for the bigger nozzles).
TDB Robot wirelessQuestionCould the TDB Robot be built 'wireless', i.e. without cables back to the control unitAnswerNo, it is not feasible to use the TDB without wires because wires are also needed to transmit power to the wheels and lights.
One advantage of the TDB is the power of its traction, which means it can:
a. pull its own umbilical cable
b. pull spray lines (biocides or coatings)
c. pull heavy compressed air lines (e.g. to the Rotating Whipstream Nozzle)
d. carry relatively heavy or large brushes
e. operate with quite heavy resistance to movement from the brush acting against the duct interior.
All these factors mean that battery-powered drive on the robot would be impractical, due to weight.
In our experience, relatively few situations actually arise where you really can not have cables running back to the control unit.
Complete duct cleaning system for commissioning a pharmaceutical plantQuestionWe need a complete Air Duct Cleaning system for commissioning of one of our pharmaceutical projects. Kindly please send us a budget cost estimate along with delivery time. Our maximum duct dimensions are 1500 mm X 500mm.
AnswerYour Pharmaceutical Plant
It is difficult to assess exactly what equipment is needed to carry out your work, but the following considerations will apply
Ø All cleaning requires two actions 1) extracting dust from the duct system and collecting it, with e.g. an Extractor, and 2) dislodging dust from surfaces, typically with brushes, compressed air or direct vacuum extraction
Ø For a pharmaceutical work, you will also need a method of testing, and so demonstrating, the level of cleanliness achieved. This is usually done by Vacuum Test, following either US NADCA ACR2006 or UK HVCA TR19 Guide to Good Practice: ‘Cleanliness of Ventilation Systems’, testing methods and standards (likely to be taken up and adapted across the EU, as a general norm, and often cited by pharmaceutical cleanliness/purity authorities)
Ø The tools you need are also heavily dependent on the access to the ductwork, and the amount and characteristics of the access panels already fitted, or to be fitted, in the duct system.
Ø Please pay careful attention to the recommended duct sizes for the various tools
Ø As a general rule, ductwork above 800mm longest side is not easy to clean with rotary brushes (e.g. DuctCleaner) or compressed air (e.g. Jetvent Tornado). This is usually not a problem since at that size a man can enter the duct and carry out direct vacuum extraction.
Ø If man-entry is not possible, e.g. the 500 x 1500mm duct you mentioned might be a little too small for safe man-entry, then the TDB Robot is always good as it offers complete, monitored control
Ø If there is very frequent access in larger ductwork, then it may be possible to clean with ‘head-and-shoulders’ access only
Ø As a general rule, compressed air is more flexible and requires less access, but physical brushing usually produces higher quality finished surfaces. Sometimes the use of both (brush, followed by compressed air) can be time-saving.
Ø Special tools, such as the Rotating Whipstream use compressed air without ‘sticking’ to the duct surface, and can be very good for risers where you want to avoid man-entry/rope-access or excessive access panels (2 per floor, typically). The Whipstream can also be fitted on to the TDB Robot for quick work at horizontal ductwork, especially where the deposits are relatively light builders’ dusts, rather than more ‘sticky’ carbonaceous and other dusts built up over years of use of the HVAC system.
Vacuum Test post-clean samplingQuestionI have some questions about the Vacuum Test sampling
1. Can the Millipore AAWP037 PM matched weight sampling filter be reused for further tests?
2. If single usage how much the cost of 50 capsules? Here the problem is customer wants us to prove cleanliness with a test, free of charge and at many points.
Could you kindly send European standard or any other standard of indoor air quality guideline and parameter as reference or recommended as guideline currently applied. Here there is no reference guideline as local standard. Laboratories are using their own standard and one lab varies from the other.
Answer1.
The filter sampler is for one-time use only. Theoretically, you could re-use the capsule with new filters, but it is not worth the trouble, and risk of contamination. A matched weight sampling filter capsule comprises two 0.8 µm pore-size filters one on top of the other. The idea is that the top filter collects all the dust and the two filters are weighed to see the difference between the top and bottom filter (since the filters were previously weighed and matched to the same weight). Working this way is better than pre-weighing one filter and re-weighing afterwards because it avoids problems such as weight being added to the filter by e.g. moisture, or contamination at some point between pre-weighing and re-weighing. You could ask local laboratories if they can provide another way of measuring weight gain on 0.8 µm pore-size filters. The British HVCA TR19 Guideline specifies matched weight filters, but the US NADCA ACR2006 and the EU prEN15780 allows either matched weight or pre-weighed filters.
2.
You would have to check with Millipore (or their local laboratory supplies agents/distributors) for the local cost of AAWP037 PM matched weight sampling filters, and find a local laboratory with a 4-point balance, i.e. a very sensitive weighing machine which is capable of measuring the very small weight increase that you usually see in post-clean verification sampling
3.
We get a good discount from Millipore because we buy in bulk and can pass on those savings through our supply and analysis service, which is based on batches of 50 capsule filters to make the shipping viable. Our customer gets analysis credits and can send capsules back as and when they are used.
4.
Please see the British HVCA: which describes post-clean verification amongst other things. The British guide pretty much follows the US NADCA ACR 2006 method for measuring and verifying cleanliness. The EU prEN15780, due for adoption in the last quarter of 2011) uses a slightly adapted method to increase the sample by 'brushing' or scraping dust off the surface and into the capsule (taken from the Finnish industry's method). The US and EU methods both require a 15 litre/minute sampling pump, rather that the previous 10 litres/minute
5.
We strongly recommend that contractors clean to a measureable standard to avoid the ‘white glove’ problem, i.e. where a customer denies that you have cleaned properly if he can get any mark at all on his ‘white glove’ irrespective of how large an area he wipes, how much pressure he applies etc. I once saw a large duct cleaning contractor nearly driven to bankruptcy by a client who made them promise that ducts would be ‘perfectly clean’. Of course ‘perfectly clean’ is impossible (or at least unrealistic economically), there will always be something present, even at molecular level, it is simply a question of what measurement technique and an agreed standard to be achieved.
6.
Our sister company offers in its quotations to ”Clean ductwork to HVCA TR19 standards (or could be US NADCA ACR 2006 standards) whereby surfaces are visibly clean and no Vacuum Test sample may show a residual deposit of more than 0.075g/m2” They then also offer a number of samples as an optional extra to the cleaning quotation.
7.
As a backstop regarding how many samples should be taken and where from, there is reference in HVCA TR19 to sampling locations “A minimum of three test points per system should be included with no less than one test point per 50 linear metres of ducting up to 300 linear metres and no less than one test point per 100 linear metres thereafter” In fact, the number of samples is usually agreed in advance by means of the optional offer of sampling in the quotation
How to connect an Archos unit?QuestionHow do I connect the Minicam (or Inspector, or TDB Robot) video output to the Archos unit for display and recording?
AnswerWhen a customer buys an Archos unit from us at the same time as a Minicam, Insopector or TDB Robot, we supply a BNC adaptor plug to convert from the BNC video output socket on the Triventek equipment to a phono socket.
You can then use the phono video cable supplied with the Archos unit to connect into the DVR (Gen 5) or Travel Adaptor (Gen 4) supplied as an optional extra with the Archos unit.
If you buy an Archos unit separately from the Triventek video equipment, you can always go to any radio spares/electronics/electrical goods retail shop and buy a female BNC to female phono adaptor.
See photo's here
Airborne Particle CountingQuestionDo I need to buy an airborne particle counter as part of my offer to customers?
AnswerIn most cases, you do not need to, and probably should not, buy an airborne particle counter. Duct cleaning cleans ducts, airborne dust conditions are too variable, too dependent on outside air, filtration etc to be managed solely by cleaning activity. Duct cleaning deals with the accumulated dirt on a surface which can re-entrain and/or condition the air passing over it microbiologically or chemically.
This is discussed in the Triventek Duct Cleaning Blog
A more relevant tool is the Vacuum Test kit (or whatever else may come out of the current EU discussions) to define surface cleanliness of ducts.
Archos unit configurationQuestionHow can I stop the screen going black when I'm recording with my Archos multimedia unit?
AnswerThe default setting is for the screen to go blank (black) after a short period of inactivity to save power. You can change the period of time under battery and power conditions.
Go to the Power settings and change the settings for Backlight Off to 'Never'.
You do need to have a more recent firmware upgrade to do this. Check that you have firmware version 2.1.04 or higher.
It's very convenient to use the wireless connection to get the firmware update practically automatically, but alternatively go to the the Archos support site to download first to your computer
For many questions, improvements and tweaks to this wonderful piece of hardware, you can get help at the Archos Fans Forum
Sizing Triventek BioBlocksQuestionHow do I select which size of BioBlock to use?
AnswerThe BioBlocks are rated by kilowatts (kW) cooling capacity of the coil. This is based on a sub-tropical climate with a system running 24/7 and gives a reasonable approximation to the amount of (condensate)water that can be disinfected over a standard 3-month period. Normally there will be a great safety margin, and if there is not (and you see this because the condensate is ‘thickening’ when you come to replace the BioBlock) then you know you need to increase the size of the block, or add more.
In the literature, we’ve tried to give some more guidance, relating typical cooling capacities to air volumes, which are sometimes easier to find out for an Air Handling Unit or Fan Coil Unit than cooling capacities, as below:
TBB45: 216L x 56W x 32H for up to 158kW
cooling (typically 16m3/sec)
TBB15: 92L x 70W x 23H for up to 53kW
cooling (typically 5.5 m3/sec)
TBB5S: 165L x 38W x 8H for up to 18kW
cooling (typically 2 m3/sec). Strip for low
profile drain pans
TBB5: 70L x 57W x 13H for up to 18kW cooling
(typically 2 m3/sec)
TBB units can be added together for larger
cooling capacity systems
Read about duct cleaningQuestionWhere can I read more about duct cleaning?
AnswerThere is a variety of material on the web and available on paper.
The best website is probably www.nadca.com, try also www.evha.com which is just getting started.
http://www.aivc.org/index.html is good for deep background/academic materials.
For German-speakers, try Marktführer Reinigung von RLT-Anlagen
There is an English-language page on the German VDI website, explaining VDI Guideline 6022 Parts 1 and 2
For Swedish-speakers, try the RSVR
See also the links page on this website
Not forgetting of course: you really should subscribe to this blog (my blog)!
There are some good paper materials to read.
Best of all would be the HVCA TR19 Guide to Good Practice: Cleanliness of Ventilation Systems. I might be a bit biased as I chaired this one.
CIBSE’s work on microbiology is useful, if only to convince you to keep it simple.
Building Services Research and Information Association (BSRIA) have a good set of FM Contractual-related documents The three HVCA TR19, CIBSE TM26 and BSRIA FMS 1/97 documents can be bought all together as a toolkit.
BSRIA used to have a really nice introduction - BSRIA Technical Note TN/L8/92 8th Edition 1996 - Ventilation Systems Hygiene - A Review. ISBN 086022452X, which has unfortunately gone out of print (after 6 editions - which is testimony to its usefulness) but they will do you a photocopy, if you phone them on +44 (0)1344 465529.
The British Health and Safety Executive produces: HSE G202 General ventilation in the workplace guidance for employers. 2000 ISBN 9780717617937 and HS(G)132 Guidance Note - How to deal with Sick Building Syndrome. ISBN 0717608611
The US NADCA has a variety of publications, including ACR2006, Inspection Procedures, Guideline for Commercial Consumers etc.
REHVA, the Federation of European HVAC Associations has some good material in its bookstore
If any reader has any other ideas for sources from around the world, please do not hesitate to contact us and I'll be very happy to add them to the list.
Slightly greasy or crusty ductsQuestionDo you have duct cleaning equipment for remote cleaning of kitchen extract ductwork which is moderately/slightly affected by grease?
AnswerYes, we do.
Rotary brushing can be a solution for remote cleaning of ductwork affected by dry-ish, ‘crusty’ deposits, not full-blown oil/grease fouling direct off the canopy.
It can be effective in e.g:
- flat/apartment block extracts affected by slight greasiness from the kitchen (or moisture from the bathroom)
- in the branch extract duct serving the dishwasher or non-cooking range areas of a commercial kitchen
- In areas of the duct system distant from the grease source where the grease deposits out in a relatively dry way.
We suggest steel brushes, or Tynex (like carborundum-impregnated grinding wheel) brush bristles which you can build up to suit with the ‘make-your-own’ brush head. I’d suggest you tak a selection of pre-made brushes because they can be more efective. If you take a few, you can try them out and you’ll probably end up buying a stock of those that you like.
These will break up and dislodge dryer grease deposits. As a rule-of-thumb, if you can clean it by hand with a stiff brush, then hard rotary brushes will work for you. Remember that you will need to extract the powdered/flaked grease/dust particles. In Kitchen extract systems, you can often use the system’s own fan, but you will often need to make some form of temporary filtration arrangement to catch the particulate. Blowing grease particles onto a customer’s car below is not recommended! The proper, and most flexible way is of course to fit on your own filter and extractor unit
Our brush drive systems are strong and designed for one-man operation with automatic, timer-variable rotation control, and a foot-pad controller.
We recognise the fact that the demands of power transmission, especially against the resistance of a stiff brush in a crusty/greasy duct, and the need for flexibility, and for light, easily manageable shafts, mean that brush shafts do break. They all do. Therefore ours are designed so that you can repair them on site, in about 10-15 minutes. They almost always break at the points of greatest stress, just behind the brush head and just by the motor drive, so you can go some before your shaft gets too short!
You might also be interested in the Jetvent Mini-cam. This is water-proof (so can be easily cleaned off). It’s a great sales and technical tool
1.
At a pre-work sales/survey meeting you can show a potential customer what needs doing and why
2.
In some instances, you might use it to make sure that very difficult-to-access areas of the duct system do actually need cleaning, or can justifiably be omitted
3.
He sees that you are a professional outfit
4.During the work, you can check - especially useful if you're working remotely
5.
After the work, you can show him what you have done, which helps him justify the expenditure, and to satisfy his insurance engineer or landlord.
The Mini-cam will output to your laptop (via an analogue video ‘grabber’)or to an analogue-capable camcorder, or you might like to use the Archos Multimedia unit which is one-touch operation and can download via USB to your customers computer, or to yours for editing with titles, captions describing location etc
Radioactive cleaningQuestionDo you know if someone has any experience in cleaning radioactive airducts?AnswerTriventek duct cleaning equipment can clean radioactive ducts
Or, to be more precise, our equipment can remove radioactive dusts from ducts (if the ductwork has become irradiated, there is nothing we can do about that).
We have a customer at present using DuctCleaner and brushes to remove quite ‘hot’ dusts.
In the particular case I’m thinking about, they initially thought of using a TDB robot, but the ductwork was too small for it to enter.
They are using their own extraction or air mover facilities (using the vent system’s own fan and filter systems). This is important because our extraction equipment filter boxes are not designed for ‘safe-change’ of the filter after it has been contaminated with radiological dusts. However our fan could be used with a client-built, or client-adapted filter system.
Do note that equipment used for cleaning (at least brushes and shafts, or possibly robots) will tend to need to be disposed of after use
Care of Brush shaftsQuestionHow can I keep my brush shafts from breaking?
AnswerThis is a good question. All brush shafts are a compromise between flexibility and strength to transmit the driving force (torque). You could have great flexibilty and very little strength such that the shaft breaks really easily. Or you can have great strength, but then the shaft is so stiff (and heavy) that it is practically impossible to work with, both inside and outside the duct.
Coming from a real, duct cleaning contractor background, means that we have developed the best compromise between practical usability and long term durability. The core is made of the finest Solingen spring steel, which is durable and will return its shape to straight, without curvature. There is a lubrication layer, an armoured layer and finall the tough outer covering.
Despite all the above, we recognise that brush shafts will eventually break - there's just too much stress on them. That's why we made ours easy to repair. You don't need to take the shaft back to your workshop and get special tools to repair it. With simple, common tools you can repair the shaft on site and quickly get back to the business of producing duct cleaning.
Here are some tips to keep your brush shafts in good condition and to minimise the risk of breakage:
- Never use oversize brushes. Always use the right size.
- Always have big curves (easy radius bends) when transporting and using the shaft. If the shaft has very sharp bends then there is more chance that it will break.
- Do not use excessive force to drive the shaft into the duct
- Use tape to protect the edges of the duct where you enter the shaft, especially at raw, cut edges
- Avoid sharp impact damage to the shaft which can be caused by e.g. running heavily loaded runner wheels over the shaft, stepping hard on the shaft etc
Kitchen Extract (Exhaust) cleaningQuestionHas Triventek got any equipment to help with kitchen extract cleaning?
AnswerYes, and no!
We have the Minicam which is excellent for inspecting greasykitchen extract systems, because it is simple and easily cleanable. This is good for showing easily a customer what the interior of his duct system looks like - before or after cleaning. It's also very useful for cleaning crews during the course of the work. It can also be useful to check very difficult-to-access parts of the system, so that you can see if it is justifiable to do e.g. costly builderswork, to inspect and/or clean that section. It does sometimes happen that parts of a system, especially those remote from the hood, are not so heavily fouled.
We also have steel and Tynex, carbide-impregnated rotary brush bristles. These can be good for domestic-style (e.g. apartment block) small circular duct extraction systems which are affected by light grease levels, where it makes the dirt 'crusty", rather than liquid or solid oil/grease deposits.
In commercial kitchens, there's no substitute for plenty of access panels and manual cleaning. Our sister company Hotchkiss Air Supply is a major access panel manufacturer.
How far can the Inspector goQuestionHow far can the Inspector go?
AnswerThe standard inspector is supplied with a 15m cable. Extra length cable can be bought on a per metre basis and extra cables can be coupled togther. The typical maximum is about 100 metres by which time the drag on the cable overcomes even this robot's powerful 4-wheel drive!
Can the Ductcleaner go both waysQuestionCan the Ductcleaner brush go both ways?
AnswerYes, it can be switched from running clockwise to anti-clockwise. This is especially important when rotary brushing rectangular ducts, to help you get into the corners.
The nice thing about the Triventek Ductcleaner is that there is an timer which you can set so that the rotation is automatically reversed at a frequency you desire. This really helps brushing to be a one-man operation.
How can I prove that the ductwork is clean?QuestionHow can I prove that the ductwork is clean?
AnswerThis is one of the most important factors for the duct cleaner. Much of what you do is 'out-of-sight-and-out-of mind', this can lead to doubt on the part of the customer.
It is therefore really important to show your customer what good work you've done. This is where the inspection and recording equipment really comes in useful. You can give a video record to your customer so that he (and his/her boss!) can see how the money has been spent.
There can often enough be a question as to 'what is clean'. All surfaces have some 'foreign' material on them, at some, perhaps microscopic, level. That's why NADCA, then the British HVCA, and now the EU CEN adopted the vacuum test as a means of defining a level of cleanliness to be achieved by normal commercial cleaning, and then to be able to test to demonstrate achievement, or not, of the specified level of cleanliness.
It was developed to avoid the 'white glove' nightmare scenario, where duct cleaners found their work being rejected by clients because it was possible to make a mark on a piece of white cloth rubbed on the duct surface (how long a swipe, how dark or heavy a mark - you get the picture - it's not too scientific). Vacuum tests, or similar provide a reasonable, test-able benchmark
Can I get trainingQuestionCan I get training?
AnswerYes, you can get commercial and technical training. Triventek Ductcleaning offers training based on 29 years experience in the duct cleaning business. Discuss with your local distributor what you want and we'll find the way to give it to you.
How to estimate duct cleaningQuestionHow can I learn to estimate ductwork cleaning?
AnswerIt cannot be denied that there is an art to estimating duct cleaning, which gets quicker and more accurate with experience.
The key things to remember are:
- Labour is the overwhelmingly predominant cost (therefore use the highest quality, most productive tools- their cost is unimportant compared to labour)
- All the time is typically taken up in getting to the duct interior, e.g. in bringing equipment to an area, removing false ceilings, fitting access. The time taken by a machine cleaning each metre of duct is relatively unimportant
- Having said the above, if you can get longer 'reach' from each access panel, you will greatly increase productivity.
All the above means that a reasonably practical person can say to him/herself: 'OK, how long would it take me to get up to the duct, fit access, attach an extractor, introduce a tool, clean as far as it can go (to the next obstruction, or until the tool runs out of 'reach'), bring the tool back, close up, clear up and move on'
Most times you then need to figure out how many similar sections of ductwork there are on the whole job.
Then you tend to compare against a benchmark e.g. you get a quantity by breaking it down into sub-sections, total up the sub-sections and then compare the total against a benchmark like:' With tool X, I should be able to do Y metres per day', to see if there are any glaring inconsistencies which would require a re-think.
Of course, as a previous Technical Director I used to work for, once said: alternatively we could drive really slowly around the car park, count how many floors and guess!
It is daunting to start off with, but anybody with an ounce of practical common sense soon gets the idea
Finally, Triventek Ductcleaning, and many of our distributors can offer training according to what you need
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