Green Building Forum - DIY leak testing

DIY leak testing

djh — Thu, 21 Jun 2012 16:51:59 +0100

I guess a source of smoke is better than a mister for this application. Not so likely to condense or be adsorbed on its way through the [pinhole] leak.

If anybody puts together an order to buy, include one for me! There are services that will accept delivery to a US address and then forward it to you.

DIY leak testing

TimSmall — Thu, 21 Jun 2012 17:12:09 +0100

I'm getting a price from Pow Science Toys - who are happy to ship internationally via USPS. Will let you know when I get something. They also do the "pro" kit.

DIY leak testing

Nick Parsons — Thu, 21 Jun 2012 17:16:38 +0100

''A friend of mine pointed out that the "Wizard Vapour Airflow Indicator" which Pro Clima sells (ends up at Â£70 or so incl VAT and delivery from your typical Passivhaus emporium) is actually a kids toy:

http://www.zerotoys.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=WS01

... fair play to them - if it does the job I suppose.''

At an 'energy weekend' I attended there was an air-tightness demo, which was great, and these 'toys', which appeared to be giving no end of trouble. Someone pointed me to a 'smoke pen' at:
http://uk.rs-online.com/web/p/leak-flaw-detection/4945963/
90 x 20-sec bursts.

DIY leak testing

SteamyTea — Thu, 21 Jun 2012 17:40:31 +0100

How about one of these, not that I have any interest in model railways, tropical fish or stamp collecting.
http://compare.ebay.co.uk/like/170779628800?var=lv<yp=AllFixedPriceItemTypes&var=sbar

DIY leak testing

Joiner — Thu, 21 Jun 2012 17:58:21 +0100

Nick, I was just directed to an ebay page that gave me a list of the last few items I'd looked at.

DIY leak testing

Nick Parsons — Thu, 21 Jun 2012 18:08:02 +0100

Try this:

Edit: Tish, doesn't seem to want to play.

DIY leak testing

SteamyTea — Thu, 21 Jun 2012 18:13:51 +0100

Was it not "SEUTHE LOCOMOTIVE/BUILDING SMOKE GENERATOR MODEL RAILWAY SCENERY ELECTRONICS"

DIY leak testing

JSHarris — Thu, 21 Jun 2012 18:17:54 +0100

A model railway smoke generator would probably do the job. Usually around Â£20 plus the cost of the oil. Pretty much any decent model shop should stock them, and they could be wired up to run from a battery easily enough.

[EDITED: cross posted with ST's description of exactly the thing]

I'm not sure about the ultrasonic mister unit, but they are so cheap that you might want a go at a DIY version. The misters are less than Â£3 inc delivery (http://www.ebay.co.uk/itm/Mist-Maker-Fogger-Mister-Humidifier-Pond-Water-Fountain-/270983779527?pt=UK_HomeGarden_Garden_PondsWaterFeatures_UK&hash=item3f17e454c7) , and could just be plonked in a small cup of water and wired to a suitable power supply.

DIY leak testing

DarylP — Thu, 21 Jun 2012 19:34:17 +0100

... for smoke, try these:

http://www.screwfix.com/p/smoke-pellets-5g-pack-of-10/64647

Cheapest 'smoke generator' I have found!

Cheers...

DIY leak testing

Nick Parsons — Thu, 21 Jun 2012 22:54:36 +0100

''... for smoke, try these:

http://www.screwfix.com/p/smoke-pellets-5g-pack-of-10/64647

Cheapest 'smoke generator' I have found!

Cheers... ''

Agree, but generally too much smoke!! You need to be able to control a smaller amount.

DIY leak testing

djh — Fri, 22 Jun 2012 13:02:29 +0100

Posted By: JSHarrisI'm not sure about the ultrasonic mister unit, but they are so cheap that you might want a go at a DIY version. The misters are less than Â£3 inc delivery

The ones I saw in Harrods last weekend cost a darn sight more than Â£3

DIY leak testing

JSHarris — Fri, 22 Jun 2012 15:13:16 +0100

Posted By: djh
The ones I saw in Harrods last weekend cost a darn sight more than Â£3

Makes you wonder about the mark up on them, doesn't it, when you can buy them direct from China, inc postage, for such a low price?

DIY leak testing

Seret — Fri, 22 Jun 2012 17:52:52 +0100

I've been known to use a jos stick myself. Cheap as chips!

DIY leak testing

Nick Parsons — Fri, 22 Jun 2012 18:12:42 +0100

Yes, I recommend them (with necessary caveats re not burning down your house based on my 'advice'!), though even a whiff is enough to set off some people with asthma.

DIY leak testing

Nick Parsons — Fri, 22 Jun 2012 18:15:00 +0100

''... for smoke, try these:

http://www.screwfix.com/p/smoke-pellets-5g-pack-of-10/64647

Cheapest 'smoke generator' I have found!

Cheers... ''

These are even cheaper, but still produce too much!

http://www.screwfix.com/p/smoke-matches-tub-of-75/64177?_requestid=597718

DIY leak testing

SteamyTea — Fri, 22 Jun 2012 21:33:02 +0100

I don't recommend these to anyone
http://www.smokescenenyc.com/Marlboro.html
If you ever see any, send then to me for disposal

DIY leak testing

djh — Fri, 22 Jun 2012 21:49:49 +0100

Nick Grant made an excellent post about this topic last year:
http://www.aecb.net/forum/index.php/topic,3040.0.html

DIY leak testing

Chris P Bacon — Sat, 23 Jun 2012 09:29:44 +0100

Posted By: djhNick Grant made an excellent post about this topic last year:
http://www.aecb.net/forum/index.php/topic,3040.0.html" rel="nofollow" >http://www.aecb.net/forum/index.php/topic,3040.0.html

He mentions a hot wire anemometer costing Â£100 but the cheapest I can find online so far is Â£185 delivered.

Anyone got a link to a cheaper one?

DIY leak testing

Sprocket — Sat, 23 Jun 2012 10:31:13 +0100

I've been distracted recently so only just found this thread.
Fantastic stuff everyone, especially RobL, thanks very much for the entertainment and food for thought.

Rob, a while back you said:-
> I've just splashed out on another bit of testkit - a CO2 ppm meter, at Â£80 from ebay.

Sounds good. I've got a couple of Elektor CO2 meters (two different sensor approaches). The sensors are surprisingly expensive and one approach has a very long warm-up.
Was that a one-off bargain you got there or is it a bit of kit others of us might be able to get on ebay for similar prices?

DIY leak testing

Sprocket — Sat, 23 Jun 2012 12:00:04 +0100

> hot wire anemometer costing Â£100 but the cheapest I can find online so far is Â£185 delivered.
> Anyone got a link to a cheaper one?

Not exactly a product you can buy, but info to roll your own.
There was an article in this months edition of Elektor.
I have the paper copy but you can get an overview here:-

http://www.elektor.com/magazines/2012/june/dual-hot-wire-anemometer.2159380.lynkx

Oh, and I just found this:-

http://www.coleparmer.co.uk/Product/Testo_Velocity_Stick_Thermal_Anemometer/WZ-37466-00

BTW, hey RobL, you did see Steamy Tea's homebrew MVHR I presume? I don't see any mention of it in this thread.

DIY leak testing

Chris P Bacon — Sat, 23 Jun 2012 12:54:00 +0100

Cheers Sprochet

I have spotted another one on eBay.com from Thailand for $199 so about Â£130, of course there is always the chance of getting stung by customs, but that is the best value I have found so far.

At that sort of money I could probably get to use it for my house and resell it afterwards without dropping too much money.

Will come in handy for commissioning the HRV as well.

DIY leak testing

RobL — Sat, 23 Jun 2012 13:29:49 +0100

Hi Sprocket
The CO2 meter that I have, which I recommend, is still available from ebay - it's this one (Â£74.9+Â£9.5 P&P):
http://www.ebay.co.uk/itm/Desktop-Indoor-Air-Quality-Monitor-Temperature-RH-CO2-/230803689663?pt=UK_Sound_Vision_Other&hash=item35bcf8d0bf

I think the sensor is a special colour led, light being absorbed by CO2 - or something like that. But TBH I haven't looked into it. It switches on and just works - no appreciable warm up, so far as I can tell accurate (well it gets outdoors about right!). Doesn't get hot, PSU that came with it is rated 5v 600mA and runs cool too.

Yes I've seen ST's homebrew MVHR - he's partly inspired me to work on a homebrew waste water heat exchanger project. I'll post up on it sometime!

Like that people get a kick from reading my exploits! Mrs Robl is very understanding :-)

DIY leak testing

SteamyTea — Sat, 23 Jun 2012 14:59:42 +0100

Posted By: RobLYes I've seen ST's homebrew MVHR

Did a bit on a waste water one as well a while back, I still think that a 'batch' system is the way to go with it.

DIY leak testing

djh — Sun, 24 Jun 2012 15:30:38 +0100

Sprocket wrote: "Oh, and I just found this:-
http://www.coleparmer.co.uk/Product/Testo_Velocity_Stick_Thermal_Anemometer/WZ-37466-00 "

Good find!

I see they also have a fog generator:
http://www.coleparmer.co.uk/Product/FlowMarker_Fog_Generator/WZ-10322-30
It's only Â£3,436!

DIY leak testing

Chris P Bacon — Sun, 24 Jun 2012 18:45:59 +0100

Just found the same the same one on ebay for Â£105 delivered. Result!

http://tinyurl.com/6mjtunt

Better again here it is in the UK for Â£107 so no chance of getting stuck for duty and vat by HRH Customs & Excise.

http://shop.testodirect.co.uk/HVACR-Products/Temperature---pressure--air-flow/Testo-405-V1-Mini-Anemometer/p-69-76-160/

[Edit] Scratch that the UK one is Â£107+VAT + delivery so I'll take my chances with the one on ebay.

DIY leak testing

TimSmall — Sun, 24 Jun 2012 20:49:02 +0100

Posted By: RobL

> The CO2 meter that I have, which I recommend, is still available from ebay - it's this one (Â£74.9+Â£9.5 P&P):

> I think the sensor is a special colour led, light being absorbed by CO2

Yes, this is the non-dispersive-infra-red type sensor - the LED version of which are the best type (the older versions use an incandescent bulb - which take a while to warm up and stabilise, plus also the incandescent bulb ages and blackens).

I looked into these a while ago for an HVAC controller design - there's a company near Glasgow which makes some quite nice sensors (e.g. small size LED-NDIR sensors, with integrated temp+humidity, and serial output), but their small order quantity prices were pretty silly >Â£100.

BTW, for another Â£15, the same ebay seller which you found does a different model with a relay for CO2 set-point control (e.g. to turn an HRV on), and which also has an RS232 interface:

http://www.ebay.co.uk/itm/330748222997

... not so pretty as the nice round one tho'

DIY leak testing

TimSmall — Mon, 02 Jul 2012 14:04:30 +0100

So I've finally started leak-testing. I originally went down the car-rad-fan+old-computer-PSU route, but then happened to spot some posh EC-motor speed controllable EBM-Pabst fans on eBay, which I got for a song...

The roof conversion is finished as far as the air-tight layer, but the rest of it isn't, with some massive holes here and there (currently stuffed with bubble-wrap and pipe insulation), except the lounge bay-window ceiling which is just open to the tiles, and howls.

Fortunately, the 3 fans which I'm using still manage to get the building up to 120 pascals as the moment - very necessary otherwise I won't be able to progress on fitting out the loft conversion (or alternatively I'd have to forgo any chance of fixing leaks) until after the extension is finished and tight.

One of the existing DG windows (one which will be going in the next week or so when the wall it's in will be coming out) emits a sound like a Kazoo at between 40 and 120 pascals...

Will post some progress when I have more to show...

DIY leak testing

Chris P Bacon — Thu, 05 Jul 2012 12:59:25 +0100

I'm edging slowly towards the point where I will want to do some DIY leak testing before getting a proper blower door test done. I reckon it is worthwhile to do that and have the comfort of a day or two of checking for leaks rather than running around like a mad thing on the morning of the blower door test.

So what I am interested in is to de-pressurise the house to a reasonable level so that I can check for leaks rather than try to estimate the actual air tightness of the house.

Having read the link that RobL posted http://www.nlcpr.com/Pressuretesting.php I am looking at using a cheap 240v fan like this one from RS http://uk.rs-online.com/web/p/cooling-fans/7001439/?origin=PSF_345653|fp

I'm attracted by the fact that it has a full cowl for safety something that you don't get with the car fans.

It's rated for 5100 mÂ³/h so it should be up to the job. But is it a big drawback that it doesn't have an outer rim around the fan tips?

I guess that this "220v Booster Fan Electronic Speed Motor Controller" from ebay should make it possible to fully control the fan speed? http://tinyurl.com/cvdblmg

And this manometer can give me the pressure differential? http://tinyurl.com/bqmyxq8

I probably don't need the speed controller if I am not trying to work out the actual air tightness figure but I guess as it's cheap it's no harm to have it and it would be quite nice to work out the air tightness on a DIY basis and see how it stacks up against the proper blower door test.

So before I go throwing out money on the wrong things would someone more knowledgeable be kind enough to verify I am getting the right stuff or if not suggest alternatives?

Thanks

Chrispy.

DIY leak testing

RobL — Thu, 05 Jul 2012 20:05:06 +0100

Hi Chris

That RS fan would work to some extent, but I worry that the large space around the blades will allow massive air flow back the wrong way, so reducing house pressure. I think you should aim for <10mm between blades and cowl.
Bit of a faff fixing it mechanically too.

How about this unit? Comes with finger guard (on one side):
http://www.ebay.co.uk/itm/16-UNIVERSAL-ELECTRIC-COOLING-TURBO-KIT-CAR-RACE-RADIATOR-FAN-STRAIGHT-BLADES-/230749849027?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item35b9c345c3#ht_755wt_952
Needs a 12v supply - Car battery or charger? You could use a car headlamp in series to drop a few volts, if you want a slower setting. TBH, top speed is the most useful anyway !

The manometer looks nice. You need to measure the airflow too to get an estimate of the ACH at 50Pa. Otherwise the manometer alone could be used to show you how much you've improved things.

Good luck !

DIY leak testing

Chris P Bacon — Thu, 05 Jul 2012 21:02:53 +0100

Thanks Rob, I forgot to mention that I have already got a hot wire anemometer for measuring the airflow so that is covered.

Looking at the car fan it doesn't seem to shift much air compared to the 220v one, 1130 mÂ³/h vs. 5100 mÂ³/h?