Is It Possible to Get Condensation on a Sponge?

first_imgI recently taught a class called What the Duct!? at the Builders’ Boot Camp in Virginia. Paul Francisco was one of the other instructors (teaching about indoor air quality), and on the last evening at dinner, our conversation turned to building science. (Imagine that!)I don’t recall exactly how we got there, but somehow the question of condensation came up. Paul talked about how Bill Rose, author of Water in Buildings, often asks the question, “Can you get condensation on a sponge?”If you’ve read Rose’s book, you probably already know the answer. Well, let me rephrase: If you’ve read and absorbed (hint, hint) the material in Water in Buildings, you know the answer. If you haven’t read the book, you may now be able to guess where I’m going with this. (But you should still get yourself a copy and read it anyway.)What is condensation?On page 81 of the book, Rose quotes Leonard Haeger from the 1952 Condensation Conference: “I suppose in the beginning we should have a definition of condensation, and to practical men condensation is what you find on a highball glass at 5:30 in the afternoon.” RELATED ARTICLESThe Physics of Water in Porous MaterialsAll About Vapor DiffusionHygric Buffering and Hygric RedistributionHow to Use the Psychrometric ChartWhen Sunshine Drives Moisture Into Walls The History of Peeling Paint, Insulation, and Vapor BarriersAre Dew-Point Calculations Really Necessary?Do I Need a Vapor Retarder?Vapor Retarders and Vapor BarriersForget Vapor Diffusion — Stop the Air Leaks!Bill Rose’s Building Science To-Do List It’s also what you get on single-pane windows (see Image #2, below), bathroom mirrors, and grass on a summer morning. It happens when air with a certain dew point temperature finds a surface that’s at or below that temperature. It occurs under precise conditions of temperature and water vapor content of the air. It’s a point on the psychrometric chart.The difference between sorption and condensationSponges, of course, can have a specific temperature and interact with the water vapor in air. Unlike a glass surface, however, some materials — like wood, brick, and perhaps sponges — collect water from the air at a wide range of temperatures. They’re sorptive materials. They adsorb and absorb water on the surfaces and in the pores.Adsorption, briefly, refers to water that’s close to and bonded strongly to a surface. When a material pulls in so much water that some of the water molecules are in the pores but not bonded strongly to the surface, those water molecules are absorbed. The two phenomena together are referred to as sorption.Wood and brick are like sponges in that regard. The graph reproduced as Image #3 (below), called a sorption isotherm, is from the doctoral dissertation of Professor Chris Timusk. As you can see, the moisture content of the material depends on the relative humidity of the air. Even if the material temperature is higher than the dew point of the surrounding air, it can collect water. And the higher the relative humidity (RH), the more water it collects.That’s not at all like condensation. As Rose says in his book, “Sorption is a better term, covering adsorption and absorption.” When you see condensation on the bathroom mirror, you know the dew point of the water vapor in the air is equal to or higher than the surface temperature of the mirror.When you see a sponge that feels damp even though it hasn’t been used in a while, its temperature may or may not be below the dew point. But as a sorptive material, it doesn’t have to be. The higher the relative humidity, the more moisture it adsorbs and absorbs.This issue comes up all the time in building science discussions, especially regarding what happens in exterior sheathing. I’ve been guilty of this, too. When it’s cold outside and a building doesn’t have exterior insulation, we often talk about “condensation” occurring when humid air from indoors finds its way to the interior side of the sheathing. As with the sponge, though, the moisture content of that sheathing depends on relative humidity, not dew point.Condensation on a sponge?So, back to the original question: Can you get condensation on a sponge? When Paul Francisco brought this up at dinner last week, he told the story of being in a session where Bill Rose asked the question and then said no, you cannot get condensation on a sponge. He gave the reasons above to support that answer.Paul then disputed Rose’s argument, saying yes, you can get condensation on a sponge. After you take a shower and have condensation on the mirror, you wipe it off with a sponge. That’s how you get condensation on a sponge.But are sponges really hygroscopic?Materials, like wood and brick, that collect moisture from the air by adsorption and absorption are called hygroscopic. When I first posted this article in my blog, commenter RoyC objected. “Sorption occurs at the chemical/molecular level. Sponges work on capillary action or surface tension, which is a macroscopic effect,” he wrote. “Maybe there are some sponges that are hygroscopic or sorptive, but I haven’t seen any. If I leave a soaked sponge out in the open long enough, it clearly ‘dries’ out.”Bill Rose jumped into the discussion at that point, replying to RoyC, “You have a point. I don’t know what the sponge is made of. I’ve had natural sponges and plastic sponges. Is there a difference between air-dry and oven-dry? I don’t know because I haven’t done it. I suspect that for an organic sponge it’s yes, and for a plastic sponge it’s close to no. And capillarity accounts for almost all the water in a wet sponge as you state.”OK, so there’s some debate about whether sponges are actually hygroscopic or not. The larger point that Rose is making, however, is still valid. When building sheathing or drywall gets wet because of contact with humid air, the process responsible for the wetting is sorption, not condensation. “I try to reserve the term ‘condensation’ for where it’s water-to-water, and avoid it with water-to-material,” Rose wrote. Allison Bailes of Decatur, Georgia, is a speaker, writer, building science consultant, and the author of the Energy Vanguard Blog. You can follow him on Twitter at @EnergyVanguard.last_img read more

Kamal Nath’s comments on migrants triggers row

first_imgUnion Minister Giriraj Singh on Tuesday sought an apology from Congress president Rahul Gandhi for Madhya Pradesh Chief Minister Kamal Nath’s remark that local people lost out to migrants from Uttar Pradesh and Bihar in jobs.“They [people from U.P. and Bihar] contribute to the progress of the State through hard work. Kamal Nath should answer whether India is a federal structure. Congress president Rahul Gandhi should apologise to the people of Bihar and U.P.,” Mr. Singh said. Mr. Nath’s comments on Monday evoked sharp reactions from the Samajwadi Party, RJD and the JD(U) as well. “This is wrong. In Maharashtra, you hear questions like why have north Indians come here? Why are north Indians doing business here? The same questions come from Delhi. Now this is coming from Madhya Pradesh. If north Indians get together and decide then who will come to the Centre?” he said.Soon after being sworn in on Monday, Mr. Nath had said, “Lot of industries are set up in which people from other States, like Uttar Pradesh and Bihar, come to work. I do not want to criticise them, but the youth of Madhya Pradesh remain deprived.” He added that his government would provide incentives to industries that provide 70% of their jobs to people of Madhya Pradesh.‘Attack on Constitution’Mr. Nath’s statement was also criticised by the JD(U) and the RJD. JD(U) spokesperson Neeraj Kumar said it was ironic that while Congress president Rahul Gandhi speaks at length about the Constitution being under threat from the Narendra Modi government at the Centre, a senior leader of his party took a stand that was an assault on the federal structure of the country.RJD MLA and spokesman Bhai Virendra said such comments should be avoided as every citizen of the country is free to live and work anywhere.The Bihar Congress unit hit back, saying the Madhya Pradesh Chief Minister was talking about providing employment to the people of his own State and that should be a priority for the government in Bihar as well.Positive spinBihar Congress working president Kaukab Qadri said Mr. Nath was not spreading hatred against the people of U.P. and Bihar, or threatening to drive them out, something which was witnessed in the BJP-ruled Gujarat and which has been a pet theme of Shiv Sena, the BJP’s ally in Maharashtra. He said the thrust of Mr. Nath was on giving incentives to employment-generating industries in the State.“Herein lies a lesson for U.P. and Bihar where the political leadership seems to have abdicated its responsibility towards its talented and hard-working youths who have to fend for themselves outside their home states,” Mr. Qadri alleged.last_img read more

Anti-violence Bills still await presidential nod

first_imgCivil rights groups in Rajasthan have expressed concern over delay in the presidential assent to Bills against mob lynching and honour killing, which were passed by the State Assembly on August 5, holding up the process for their enforcement.Since some punishments laid down in the two Bills were higher than those in the Central statutes, the assent of the President, rather than the Governor, is essential. The State government sent the Bills to the Ministry of Home Affairs earlier this month to be forwarded for the President’s consent.People’s Union for Civil Liberties-Rajasthan president Kavita Srivastava said here on Saturday that since the MHA was sitting on the anti-mob violence Bill sent by the Manipur government since January this year, the fate of the two Bills of Rajasthan was likely to be the same. “The MHA seems to be have put these Bills in cold storage,” she said.“Our concern regarding the fate of the two Bills also stems from the fact that the Ministry of Home Affairs has not been interested in the enactment of legislation on lynching and honour killing crimes,” Ms. Srivastava said, while pointing out that the Group of Ministers to tackle lynchings, headed earlier by Rajnath Singh and now by Amit Shah, had not met.“The Centre’s view submitted to the Supreme Court in the Tehseen S. Poonawalla case was that the Indian Penal Code and other existing laws were enough to handle the lynching-related violence,” Ms. Srivastava said.As regards the honour crimes law, the rights groups felt that the political parties, particularly the BJP, did not wish to interfere with the violence of the families, ‘Khaps’ and caste panchayats. The PUCL called upon the State government to put pressure on the MHA to the get the Presidential assent and said it would launch a campaign to get the President to sign the two laws.Both the Bills have made stringent provisions of punishment and penalties for the offences of mob lynching and honour killing, making them cognisable and non-bailable offences. Those convicted of the crimes will be punished with life imprisonment and a fine up to ₹5 lakh.last_img read more

10 months agoNewcastle boss Benitez raps Man Utd: No excuses for top 4 failure

first_imgAbout the authorPaul VegasShare the loveHave your say Newcastle boss Benitez raps Man Utd: No excuses for top 4 failureby Paul Vegas10 months agoSend to a friendShare the loveNewcastle United boss Rafael Benitez says Manchester United have no excuses if they fail to finish in the top four.United travel to St James’ Park to face Benitez’s Newcastle on Wednesday.”It’s a team that has to be easily in the top four, that is very clear,” said the Newcastle boss.”They can compete against Manchester City, Liverpool, anyone. We are talking about one of the biggest clubs in the world in terms of everything.”The players they have, they are so good that if you want to win or get points against them you have to perform really well.”When you are a top side like Manchester United, spending millions every year, you have to be in the top four and you have to win the title.”For them, that’s the pressure. Not just now, they had it before, and for sure they will feel the pressure in a few weeks when they will be there fighting with Tottenham, Chelsea, City, Liverpool and Arsenal.” last_img read more

The feuding feral cats of HMC Dockyard – and the exsailor who

first_imgHALIFAX – Pierre Filiatreault looked out his office window at Halifax’s naval base 12 years ago and saw two tiny kittens playing together in a narrow alleyway.The kittens — one with fluffy orange and white fur and one all black — appeared malnourished and without a mother, so Filiatreault began feeding them.He fashioned a small makeshift shelter out of Plexiglas and other scrap materials. The pair could often be seen cuddled together inside the enclosure, resting their heads on each other’s back paws, their bellies touching.Eventually the naval officer took them to the SPCA, where they were adopted. But the two kittens were not the only felines roaming the base in search of food and shelter.Feral cats are a common sight at HMC Dockyard — home to Canada’s East Coast navy, including frigates and the submarine HMCS Windsor.Filiatreault retired in 2009 as a petty officer first class after serving 31 years in the navy, but he still visits the base near downtown Halifax every day to feed the roughly 20 stray cats that call it home.“The cats are part of my life now. As you feed animals, you get attached to them,” said Filiatreault in front of a cat shelter dubbed “Saraphyna” that’s nestled into a ledge that overlooks the Halifax harbour.“It’s not work anymore. They’re part of the family.”Filiatreault, also known as the Catman, has special permission from the Defence Department to maintain several cat shelters at the yard and enter the base each day to feed what have become known locally as the “dockyard cats.”In 2005 he started to trap, neuter and return the cats to help control the population. Kittens have not been born at the base in roughly nine years, and the oldest cat is now around 14. Feral cats usually only live two or three years.Each has a name — like Binoo and Black Chin — and will come to Filiatreault when called. They respond to three languages, given Filiatreault is French and his wife Paola — who helps with the feeding — is Italian, and both speak English.There are two cat colonies at the dockyard, referred to as the “city” and “country” cats.On the south end, a contingent of black and white cats roam a concrete jungle-of-sorts amidst the bustle of Canada’s Atlantic naval fleet.They can be seen scampering up wooden planks Filiatreault has attached to the side of buildings, allowing them to navigate from an upper roadway to an oceanside docking and loading area.The four-legged furballs sometimes trot along the wharf alongside uniformed officers and snooze in the shade under row boats stored on racks.The city cats eat inside the “Catty Shack” shelter — a white barn-style shed with a cat door that sits in the shadow of the Macdonald Bridge and is nestled among shipping containers and the base’s post office. Around back is one of Filiatreault’s first shelters he built in 2005 from an old fridge.The Catty Shack is heated with light bulbs, keeping it at about 10 C, and inside are cubbies equipped with cat beds and an endless supply of dry food.It’s the first stop on the daily run — when Filiatreault or his wife check on their feline friends, give them deworming and anti-flea medications and bring more desirable edibles.“They love treats. My wife spoils them — chicken, ground beef, steak or ham, depending on the season,” said Filiatreault, scooping out wet cat food onto a dish and mixing it with vitamins.“They’re friendly, but they are feral cats so you cannot touch them.”Meanwhile, the north end cats are happy trotting through tall grass or napping inside an old boat — dubbed “the Ark” — which sits in a small green space and is covered by wood framing and Plexiglas for added protection from the elements. Cina, who has long orange fur, can often be found sleeping inside.Placid, a short-haired white cat that has undergone three knee surgeries, is the local boss. He often perches on a retaining wall that overlooks the Saraphyna Shelter and Ark below.Multi-coloured Cleo has also proven to be somewhat of a chieftain of her clan. She recently defended their territory when another cat — Benny from the city colony — wandered in.“She was quite adamant that they did not want him there,” he said. “It’s like street gangs. It works the same way with feral cats. They all have their own section of the dockyard.”Navy officers will sometimes come visit the country colony on their lunch break, bringing treats.There are only a couple dozen cats now living at the dockyard, but that number was once closer to 100 in the 1990s, before Filiatreault took an interest.He raises money to keep the dockyard program running under Pierre’s Alley Cat Society, which is in its 10th year. Cats can be sponsored on a monthly or yearly basis, which pays for their food and any vet visits.Filiatreault said the Defence Department has always been supportive of his initiative and has even provided funding and manpower when the shelters were first constructed. There was a ribbon-cutting ceremony for the opening of the Catty Shack.He said he will continue the dockyard program until its natural conclusion — when the remaining residents live out their lives.“All animals deserve a chance to live,” said Filiatreault. “It could be another two years or it could be five years, but I’m in it for the long haul.”Follow (at)AlyThomson on Twitter.last_img read more

Nick Foles Is Not Carson Wentz And The Eagles Adjusted Accordingly

Foles did little to suggest otherwise in four mostly lackluster appearances to close the regular season. But he spent the month of January proving himself up to the challenge. With 352 yards (on 26-for-33 passing) and three touchdowns versus Minnesota, he produced one of the greatest QB performances in conference championship history. The game brought back memories of Foles’s 2013 season in Philadelphia, when he posted the third-best single-season passer rating in NFL history. But it was also a testament to the adjustments that Philadelphia coach Doug Pederson made to accommodate the different strengths of Wentz and Foles.Under both Wentz in the regular season and Foles during the playoffs, the Eagles’ offense averaged over 390 yards per game. But those yards were accumulated in different ways. Before Wentz’s injury, Philly was a balanced team whose aerial attack primarily relied on the power of its quarterback’s arm — often assisted by Wentz’s magician-like ability to improvise and buy time in the pocket. One thing it didn’t do, however, was ask receivers to do lots of work after hauling in the football. Through Week 14, Wentz led the league in touchdown passes per attempt and ranked third in air yards per attempt, according to ESPN’s Stats & Information Group, but his targets were only 22nd in yards after the catch per reception.Foles connected on three 40-yard passes against the Vikings. But those have been big exceptions to the Eagles’ general approach with Foles at the helm, which has been to throw much shorter. In the playoffs, Foles’s average pass has traveled 7.1 yards through the air. Compare that with Wentz’s average of 9.8 air yards per attempt during the regular season, and you can begin to see how Pederson has shifted his offense’s focus. Forty percent of Wentz’s passes went 10 or more yards downfield, compared with 25 percent for Foles in the playoffs. And Foles has actually thrown a larger share of his passes to players at or behind the line of scrimmage (29 percent) than 10 yards past it. *Playoff games onlySource: ESPN Stats & Information Group Carson Wentz7.74.812.415.5%44.3%40.2% Philly’s passing offense changed in the playoffsDistance traveled through the air — and after the catch — for passes by Philadelphia Eagles quarterbacks, 2017 season In today’s NFL, throwing shorter passes isn’t always correlated with better outcomes. But Foles is succeeding in large part because his receivers are taking those short passes and running for big gains after the catch. With Wentz under center, the Eagles’ pass-catchers produced only 98.6 yards after the catch per game (eighth-fewest in football); with Foles in the playoffs, they’ve nearly doubled that output (164.5 YAC/game). In particular, they’re doing a ton of damage on screen passes, which Pederson seldom utilized with Wentz. Running back Jay Ajayi, for instance, went from gaining just 7.4 yards after catch per game with Wentz during the regular season1In the five games immediately after Ajayi was acquired from the Miami Dolphins in late October. to 51.0 yards per game in the postseason, including nearly 30 receiving yards per game on screens alone. Foles is also making smart reads and getting the ball out very quickly. In the playoffs, he’s averaging 2.39 seconds before each pass, a mark that would have been fourth-fastest in the NFL during the regular season. (Wentz, for comparison, was 17th-fastest, at 2.54 seconds.) Foles has used that quick release to lethal effect when conducting the run-pass option — which is more than just a ubiquitous piece of announcer-speak during Eagles broadcasts. The RPO helps freeze defenses with the added threat of handing off to a dangerous runner like Ajayi, and it lends itself to the types of quick passes that Foles has excelled at this postseason. Philly ran plenty of RPOs even before Foles took over, but that section of the playbook has been crucial to Pederson’s resurrection of the Chip Kelly-era version of Foles.Now, it remains to be seen which version will show up for the Super Bowl this Sunday. The conditions have been right for Foles to succeed in the playoffs thus far — Philadelphia hasn’t had to play from behind much and has enjoyed one of the league’s most drastic home-field advantages. But there’s no telling what will happen if things go off script. That’s why the Eagles need to stay out of third-and-long, where the drop-off from Wentz to Foles is really glaring. (On third down with 8 or more yards to go, Wentz was the NFL’s top passer this season according to ESPN’s Total Quarterback Rating; only Green Bay’s Aaron Rodgers was even remotely close.) They need to keep feeding the ball to Ajayi, who’s averaging roughly the same number of yards from scrimmage in these playoffs (98.5 per game) as he did during his All-Pro season with Miami in 2016. And perhaps most importantly, Foles needs to keep playing mistake-free football: Only 8.2 percent of his passes have been off-target this postseason — a rate that would easily have ranked No. 1 in the league during the regular season.He could do all of that, of course, and still fall short: Tom Brady could always reach into his bag of comeback tricks, and there’s also the small detail of Brady and Bill Belichick’s 15-0 record in the playoffs against teams that they’re facing for the first time in a season. But putting those metaphysical factors aside, the Patriots have their own vulnerabilities. They aren’t exactly a defensive powerhouse, having ranked ninth-worst in the NFL in expected points added during the regular season. And although that number improved as the year went on, they still allowed the league’s fourth-highest QBR on passes that traveled fewer than 10 yards through the air — the kinds of throws they’re likely to see a ton of from Foles and company. If the Eagles can execute their newfound offense and resist Brady’s supercharged comeback powers, there are plenty of reasons to think Foles (of all people) will be the one to deliver Philadelphia its long-awaited Super Bowl parade down Broad Street.Check out our latest NFL predictions. Around Thanksgiving, the idea that the Philadelphia Eagles would make it all the way to Super Bowl LII wouldn’t have surprised many people. Philadelphia started the season 10-1, and quarterback Carson Wentz emerged as the front-runner for league MVP honors. But after Wentz was lost to injury in Week 14, the Eagles’ title chances seemingly disappeared, too. Backups — like Philly’s stopgap, Nick Foles — seldom carry a team to Super Bowl glory. Yards/Completion …% of Passes by Air distance QuarterbackThrough AirAfter CatchTotal<=0 Yds1-10 Yds10+ Yds Nick Foles*5.56.712.228.646.025.4 read more

Gerrard hopes FC Ufa win redtape race

first_imgRangers Football Club manager Steven Gerrard hopes FC Ufa win their red-tape race ahead of both teams UEFA Europa League playoff clash on Thursday.Gerrard hopes the visa issues facing the Russian club are resolved ahead of their tie on Thursday night.FC Ufa play against Dinamo Moscow today and will plead with the UK Embassy in the Russian capital to speed up their application.“We are actively engaged in trying to obtain British visas,” said FC Ufa President Gazizov, according to Daily Mail.“But everyone must understand it is a very difficult situation. After the game against Dinamo, we will go with our prepared documents to the British Embassy.”“We hope they are able to accelerate the process, but we will know for certain what is happening on Monday. We have been told even the accelerated process takes a minimum of five days, so that would not be enough time for us.”Steven Gerrard, Michael OwenOwen reveals why Liverpool didn’t offer Gerrard a new contract Manuel R. Medina – September 6, 2019 According to Owen, the Reds wanted to sell Gerrard two years before he left the club and that’s why they didn’t offer him a contract renewal.Gerrard, though, doesn’t want any favours from red tape. He is eager for the chance to record another Europa League win and move to the brink of the group stage.“I heard about it just before the game and we will have to wait and see how that pans out,” said the Ibrox boss, speaking after Alfredo Morelos hit a hat-trick in yesterday’s 3-1 win over Kilmarnock in the Betfred Cup.“I hope they get them (visas) and I hope they come. We are in a good place, we are looking forward to the game and the challenge and we want Ibrox to be rocking again for another great European night.”Rangers suffered a blow when Jamie Murphy suffered a potentially serious knee injury at Rugby Park, but Gerrard was otherwise delighted with the display less than 72 hours after a successful trip to Maribor.last_img read more

Gonzalo Higuain back to training after ten days of absence

first_imgAccording to the Italian portal Calciomercato, AC Milan striker Gonzalo Higuain has returned to full training after missing two straight Serie A encounters with Sassuolo and Empoli.A nasty looking thigh injury that threatened to sideline the former River Plate star for a while seems to be a false alarm, as Higuain should feature already in the next weekend’s encounter with Chievo Verona.The 30-year-old Argentinean arrived at the Stadio San Siro this summer from Juventus, as the Rossoneri desperately tried to secure the services of a top-class forward.After scoring a goal on his debut in a friendly match against Real Madrid, Higuain has made the Serie A breakthrough against Cagliari, after which he broke the deadlock against Atalanta in the following fixture. He also buried Milan’s winning goal in the Europa League opener against Dudelange.Rick Karsdorp, Roma, Serie AKarsdorp reveals he had too much stress at Roma Manuel R. Medina – September 14, 2019 The Dutch defender has been with the Gialorrossi since 2017, but he has not enjoyed his time in the Italian Lega Serie A.Higuain’s goal pic.twitter.com/e8G4xm0jPN— #FreeLocatelli (@semo33) September 23, 2018With the Rossoneri’s Europa League clash with Olympiacos around the corner, Gennaro Gattuso might be looking to rest his number nine to avoid further complications and instead field Patrick Cutrone who seems to be finding his last season’s form.last_img read more

Emery looking forward to Liverpool test

first_imgArsenal manager Unai Emery says his side will test their progress when they face league leaders Liverpool at Anfield on Saturday.Liverpool moved six points clear at the top of the Premier League after their 4-0 victory against Newcastle United on Wednesday, while Arsenal’s 1-1 draw at Brighton leaves them at fifth place and two points behind Chelsea.Arsenal’s form and performances have been inconsistent so far this season and Emery believes playing Liverpool will be a benchmark for measuring their progress.“It is a very big match for us and them. They are unbeaten this season and will be confident,” Emery told Sky Sports.“For us, it is a big challenge and a good test, of who we are and the difference between them and us.Jadon Sancho, Borussia DortmundCrouch: Liverpool could beat Man United to Jadon Sancho Andrew Smyth – September 14, 2019 Peter Crouch wouldn’t be surprised to see Jadon Sancho end up at Liverpool one day instead of his long-term pursuers Manchester United.“In the table it is clear but I also want to look on the pitch. We have had one test against them, at the Emirates, which we drew [1-1 in November].“We played a good match but I think in Liverpool it is going to be a different game to the one we played here.”last_img read more