Radon and a Passive House

first_imgA radon mitigation system to the rescueFortunately, we were able to prevent radon from entering through the small gaps in our air and vapor barrier through a conventional radon mitigation system.The conventional system was built by drilling an 8-inch-diameter hole through are basement slab and removing about 5 gallons of the gravel found there. A 4-inch PVC pipe was inserted into the hole and the hole was sealed back up. The pipe travels out of the basement and into the adjoining garage and then out the garage wall.A 20-watt fan was connected to the pipe and run continuously to create negative pressure underneath the slab. Because the pressure under the slab is now less than the pressure indoors in the basement, there is no longer a vacuum effect and soil air is not sucked into the basement through existing gaps. Fortunately, we were able to achieve the desired result with a small fan drawing only 20 watts to keep electricity usage to a minimum.So, while a Passive House’s balanced ventilation and airtightness sound like they’d be helpful preventing elevated levels of indoor radon, they don’t do enough to make a difference. In particular, air leakage permitted by the Passive House standard can allow substantial amounts of radon to infiltrate a home.I don’t believe, unfortunately, that achieving the Passive House standard significantly reduces the risk of having a radon issue in your house. On the positive side, if you have a Passive House with a radon issue, it can be addressed with a conventional radon mitigation system. In houses without balanced ventilation, this vacuum cleaner effect can be exacerbated by exhaust fans, dryer vents, and mechanical heating and cooling systems. As air is forced out of a house, unconditioned air enters through gaps in the lower portions of the house.Although a Passive House has a balanced ventilation system, the pressure in the soil around the foundation still tends to have higher pressure than the house’s interior. I conclude this based on the fact that my house has a balanced ventilation system as well as a radon problem isolated in the basement. Using fresh air to dilute radon concentrationsA Passive House’s balanced ventilation can also reduce the level of radon in a house by exhausting the air with elevated levels of radon from a basement and supplying fresh outdoor air with lower levels of radon. Doubling the rate of ventilation can cut the radon level in half. In our house, I saw short term (7 day) radon levels (measured with a Safety Siren Radon Gas Detector) range over the course of a year from 3 pCi/liter up to 12 pCi/liter. We would have had to quadruple the rate of ventilation in order to reduce the highest detected levels below 4 pCi/liter as recommended by the EPA. This was not possible the way our ventilation system was designed. So, while our continuous exhaust of basement air reduces the amount of radon in our basement, it doesn’t reduce it nearly enough to mitigate our moderate radon problem.A Passive House’s balanced ventilation has two seemingly positive characteristics with respect to radon infiltration and exhaust which, at least in our case, fell short of preventing elevated indoor radon levels. So, the question now is, why doesn’t the airtightness requirement for a Passive House prevent enough soil air containing high levels of radon from entering the building? Let me start out by stating that I am neither a radon expert nor a Passive House expert. That said, I do have experience with radon gas in a Passive House that I’d like to share.According to FAQ page on the Passive House Institute U.S. (PHIUS) web site, Passive Houses are (by design) well protected from radon. PHIUS attributes the radon-preventing attributes of a Passive House to its rigorous airtightness metrics and balanced ventilation. Yet our home is a certified Passive House that had a radon problem until a conventional radon mitigation system was installed. I don’t believe that achieving the Passive House standard did much to reduce the likelihood of our having a radon problem.According to the EPA’s “A Citizens Guide to Radon,” radon occurs naturally in soil and rocks in which home foundations are placed. Radon can be found all over the country. In our area (northwest Connecticut) there is approximately a 40% chance of radon existing on the site of your home, according to a local expert. All it takes is a dime-sized gapTo prevent radon from infiltrating a house through airtightness requires close to 100% effectiveness below grade. Our house was designed and built with an elaborate air and vapor barrier surrounding the foundation (although based on our initial blower-door test this barrier was not at all necessary to achieve the Passive House airtightness standard). I suspect that others who build Passive Houses have similar below-grade air and vapor barriers. The barrier was designed to be continuous with both penetrations (well and septic) sealed with spray foam.My expectation was that this air and vapor barrier would keep all soil air with its high radon concentrations out of the house. Unfortunately, it seems to have at least one dime-sized gap as evidenced by the elevated radon levels in the basement.Here is a link to a photo album with pictures of the foundation and barrier for anyone interested. Our house is tightOur house beat the Passive House airtightness standard by more than 35%. It had an airtightness measure of 0.38 ACH50 (air change per hour at 50 pascals) with a corresponding reading on the blower-door test of about 180 cfm.This means that under normal unpressurized conditions, air leaks into our house at a rate of about 300 liters/minute. I’ll assume that the air entering our house through the balanced ventilation system has radon levels of 0.5 pCi. Soil air in the U.S. typically has radon levels of 200 to 2,000 pCi. I’ll assume that our soil has a radon level of 750 pCi which is considered in the middle of an average risk area (270-1,350 pCi, according to “A Living Radon Reference Manual”) for radon.If the source of air in our basement were a mixture of 99.5% 0.5 pCi air from the ventilation system and 0.5% 750 pCi soil air, then we’d see radon levels of 4 pCi in the basement. Our basement contains about 300,000 liters of air, and 0.5% of this is approximately 1,500 liters. If all the air leakage in our house occurred below grade with soil air, it would take about 5 minutes to leak 1,500 liters of 750 pCi soil air. If only 1% of the leakage in our house occurred below grade, it would take 8 hours.The entire volume of air in our basement is exhausted by the ventilation system every 16 hours, so 1,500 liters leakage in 8 hours should be enough maintain radon levels at 4 pCi in the basement. I don’t know the actual soil air radon levels (although our well water tested at 2,500 pCi and 5,000 pCi, so 750 for the soil seems reasonable to me) or the percentage of our house’s leakage occurring below grade, but nonetheless, I’m not at all comforted that the Passive House airtightness requirements have any meaningful effect on preventing radon infiltration. In fact, our house exceeded the Passive House standard on the initial blower-door test under conditions that were ideal for radon infiltration, with a gravel basement floor prior to the concrete slab being installed. Paul Honig lives in a passive house in the northwest corner of Connecticut with his wife Diane and two boys. He enjoys teaching math and playing roller hockey. Paul and Diane are the authors of a blog called Our Connecticut Passive House. All About RadonExhaust-Only Ventilation Systems and RadonRadon and AirtightnessEPA Issues Radon ReminderGBA Detail: Retrofit for Radon Vent Radon enters a home through foundation cracksRadon gas enters a home through gaps in the structure (typically a foundation) that separates the below-grade interior of a home from the earth that surrounds it. The local expert we saw explained that even a tiny gap the size of a dime can lead to elevated levels of radon in a home. The atmospheric pressure in the ground tends to be higher than the atmospheric pressure in a house’s interior. As a result, a basement can act as a sort of vacuum cleaner motor that sucks in radon in soil air through any of these small gaps. Radon gas can then accumulate to levels that according to the EPA can lead to increased risks of lung cancer. RELATED ARTICLES last_img read more

Racal smothers Gamboa in 2nd half to halt 3-game slide

first_imgRian Ayonayon. PBA IMAGESRacal Motors locked down Gamboa Coffee Mix in the second half to win, 107-60, in the 2017 PBA D-League Foundation Cup Monday at Ynares Sports Arena in Pasig.After a tightly contested first half, the Alibaba limited the Coffee Lovers to just three points, the least points scored in a quarter in league history, that turned a close 47-45 deficit to a decisive 71-50 advantage.ADVERTISEMENT Pagasa: Storm intensifies as it nears PAR Lacson: SEA Games fund put in foundation like ‘Napoles case’ Don’t miss out on the latest news and information. Racal continued to choke the air out of Gamboa as the latter’s 13-point windup in the second half also registered as the worst scoring half in PBA D-League history.Rian Ayonayon scattered 26 points, seven assists, five steals, and four rebounds to lead the Racal Motors assault.FEATURED STORIESSPORTSSEA Games: Biñan football stadium stands out in preparedness, completion China furious as Trump signs bills in support of Hong Kong LOOK: Jane De Leon meets fellow ‘Darna’ Marian Rivera LATEST STORIES Robredo: True leaders perform well despite having ‘uninspiring’ boss PLAY LIST 02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City01:07Trump talks impeachment while meeting NCAA athletes02:49World-class track facilities installed at NCC for SEA Games El Nido residents told to vacate beach homes MOST READ GAMBOA COFFEE MIX 60 – Montuano 13, Parala 12, Avenido 10, Padilla 8 Acibar 7, Arellano 4, Acuña 3, Knuttel 2, Dadjilul 1, David 0, Riva 0, Vidal 0, Jumao-as 0.Quarters: 24-20, 45-47, 71-50, 107-60.Sports Related Videospowered by AdSparcRead Next Ethel Booba on hotel’s clarification that ‘kikiam’ is ‘chicken sausage’: ‘Kung di pa pansinin, baka isipin nila ok lang’ “For now, it’s a good springboard for us. It gives us a lot of positivity and well build on that,” said coach Jerry Codiñera.Gamboa continued its downward spiral as it incurred its sixth straight loss to fall to 1-6.Mark Montuano got 13 points and 10 rebounds to lead the Coffee Lovers, while Mike Parala added 12 markers and 10 boards.The scores:RACAL MOTORS 107 – Ayonayon 26, Tallo 16, Cortes 11, Apreku 11, Pontejos 10, Gomez 8, Capacio 7, Grimaldo 6, Faundo 5, Lozada 5, Ortuoste 2, Mangahas 0, Dela Cruz 0, Cabrera 0.ADVERTISEMENT Pagasa: Kammuri now a typhoon, may enter PAR by weekend Tanduay sets PBA D-League record with 76-point rout of Zark’s Another vape smoker nabbed in Lucena SPORTSPrivate companies step in to help SEA Games hostingSPORTSWin or don’t eat: the Philippines’ poverty-driven, world-beating pool starsMac Tallo came off the bench and shot a perfect 10-for-10 from the charity stripe to finish with 16 markers, on top of his two boards and two dimes, while Jam Cortes got 11 points and seven rebounds in the victory.Racal finally ended its three-game losing skid and evened its record to 3-3. View commentslast_img read more

a month agoLindelof: I’m a better person for Man Utd move

first_imgAbout the authorPaul VegasShare the loveHave your say Lindelof: I’m a better person for Man Utd moveby Paul Vegasa month agoSend to a friendShare the loveManchester United defender Victor Lindelof is happy to put down roots.The Swede penned a new deal this week.He told the club’s website: ““I think I’ve matured a bit more in my way of playing and upped my game a little bit more. Also, the things that I’m good at I’m even better now than I was before. Then, as a person, the club have helped me a lot, as have the players, and I think I’m a better person now.“I hope [I can develop] a lot, I want to be even better and I want to help the team win trophies and games. I want to improve and be even better than I am today, that’s my main goal, and I know I have to work very hard to achieve that. I think I’m at the right club to do that.” last_img read more

Ohio State dodgeball team set to host national tournament

A national tournament is coming to Ohio State. The sport involves throwing a round ball. If you guessed baseball, you’re wrong.The Ohio State club dodgeball team is set to host the sport’s national tournament at the RPAC Saturday and Sunday.Ohio State (6-5) is a founding member of the National Collegiate Dodgeball Association, which started in 2002. OSU has attended every national tournament and has two championships, 2005 and 2006.The Buckeyes have played in three tournaments so far this season including the Round Robin tournament at OSU, the Redhawk invitational at the University of Miami University (Ohio), and the Ohio Dodgeball Cup at Kent State University.Jeff Starr, a second-year engineering student and club dodgeball member said OSU should have won more games this year and that the team is better than its record reflects. He is expecting a good result this weekend at nationals.“I think that we will actually do amazing,” Starr said. “We’ve been really close with a lot of the top teams and a lot of those tournaments, we didn’t have all of our guys. We weren’t all 100 percent. I think everyone is going to be ready to go, 100 percent.”Currently there are between 25 and 30 active members, coach, and OSU alumnus, Jude DuPart said.DuPart said not all members travel to tournaments because of midterms or scheduling conflicts, which is the reason some teams play more matches than other teams.“It really varies on how much traveling you can do. So the teams up in Michigan that are a stone’s throw away … there’s four teams up there that are all about two hours to 30 minutes away from each other,” DuPart said.DuPart said the biggest benefit of having the tournament at home is getting more players involved.“We’ll definitely be able to see a lot more kids get out there and play,” DuPart said. “A lot of kids have other obligations and can’t make the travel commitments to be able to play and see a large competitive style game.”Aside from not having to travel, Starr said another advantage of hosting the national tournament in Columbus comes with team members having the comfort of sleeping in their own beds.“Last year, we were sleeping on a motel floor, so having our own beds will be nice,” Starr said.OSU team captain Josh Connor, a second-year in logistics management, agreed with Starr that home court advantage is a big deal, especially in a big tournament.“With any sport you’re playing in, having the crowd behind you will win you the momentum. Having your friends and family behind you goes a long way,” Connor said.Starr added it’ll be nice to hear cheers for the home team.“We definitely get a lot more home fans cheering for us and not for the other teams, that’ll help,” Starr said.DuPart said OSU finished fourth in the national tournament last year. This year he is hopeful for a good result despite the more experienced teams.“Despite being a younger squad I think we’ve picked up (play) well. We’re looking pretty good,” DuPart said. “I do think there are a lot more mature teams and a lot of other teams that play pretty well, especially Grand Valley and Kent (State) is looking good this year.”Connor expects to do better at nationals than last year with a young but confident squad.“We had a pretty good season last year, I think we’re going to do better than that,” Connor said. “We’ve grown a lot, I can speak for myself I’ve become a lot more aggressive and that carries across the board. I think we have a lot more guys who feel comfortable. I think the camaraderie is even strong than it was.”The tournament is set to begin Saturday with group play from 8 a.m. to 6 p.m. in the lower RPAC courts. It continues Sunday from 8 a.m. to 5 p.m. with single elimination tournament style play. read more

Down the rink Columbus Blue Jackets recap – Week 7

Right wing Cam Atkinson signed a seven-year contract extension on Nov. 17 with the Blue Jackets. Credit: Courtesy of TNSThe Columbus Blue Jackets bounced back from three straight losses the week before to take two games against quality opponents.Defenseman Zach Werenski buried an overtime goal against Montreal and goalie Sergei Bobrovsky had a 36-save, 2-0 shutout victory for his 21st career shutout with Columbus against the New York Rangers.Before the Jackets face off with Buffalo in New York on Monday night, here’s the rundown from this past week’s three major storylines.Tortorella searching for answers defensivelyAs expected, the top defensive line of Seth Jones and Zach Werenski have continued to be the force carries the Jackets in their own zone. Past that, the defense remains largely unsolved. The difference this week, head coach John Tortorella is sending a message.He surprisingly made David Savard a healthy scratch Friday against the Rangers due to his play. Savard has been a defensive staple for the better part of four seasons, but the blue-liner certainly hasn’t played up to par to this point. Rookie Gabriel Carlsson replaced Savard on the second line.The second defensive pairing of Jack Johnson and David Savard gave up the only goal the Jackets allowed this week in a continued downward spiral from two of Columbus’ most consistent defenders last season. The two have the lowest plus-minus rating of any defensive fixtures in the lineup. Both recorded career-highs in plus-minus last year — Savard plus-33, Johnson plus-23.Savard will be back in the lineup Monday with Carlsson being sent back to Cleveland, the American Hockey League affiliate of the Blue Jackets.Zach Werenski finding offensive rhythmIt’s no secret the Blue Jackets have struggled on offense this season, despite having some of the best young talent in the Metropolitan division. Even for defensemen, that can be frustrating. But Werenski found the back of the net twice, both in game-winning fashion. His overtime goal against Montreal then a second-period wrister against New York.His offense from the blue line is arguably just as important as getting the forwards onto the scoring sheet. If Werenski can carry his two-game goal streak over to the power play, the Jackets can return to offensive prominence as many expected before the season.Atkinson signs seven-year extensionThe next two offseasons are going to test the front office, with 15 players listed as an unrestricted or restricted free agent in the 2018 and 2019 offseasons. But team president John Davidson and general manager Jarmo Kekalainen can cross one off the board with a huge seven-year deal, reportedly in excess of $40 million to Cam Atkinson. The new deal also includes a no-move clause.Atkinson, 28, has led the Jackets in scoring the past two seasons and should remain a big part of the franchise’s offense for years to come.He failed to record a point in his first game on Friday since his signing, but fired a team-high seven shots and moved furiously through the Rangers defense, attacking the net on each shift.Injury reportThird-line left wing Matt Calvert was placed on injured reserve on Nov. 6. Calvert is expected to miss three to four weeks with an upper body injury.Fourth-line center Lukas Sedlak is on injured reserve with ankle injury retroactive to Oct. 23.Alexander Wennberg has missed the past two games with unknown injury.Looking aheadCurrently on a three-game winning streak, the Blue Jackets are tied atop the Metropolitan division with Pittsburgh and New Jersey with 25 points. After Monday, they have four of their next five games at home against four teams that have winning records.Top performers (skaters)Zach Werenski – two goals (6), two points (12), +2Brandon Dubinsky – two assists (6), two points (8), +1Josh Anderson – one goal (7), one point (10), +1Artemi Panarin – one goal (4), one point (14), 1 power-play goalGoaltending:Sergei Bobrovsky – 2-0-0 (11-4-1), 0.50 goals allowed average (2.02), 64 saves, .985 save percentage (.933)In the circle (faceoff record, faceoff win percentage, EV record, PP record, SH record)Brandon Dubinsky – 34-16, 68.0, 29-14, 0-0, 5-2 Nick Foligno – 16-19, 45.7, 12-19, 3-0, 1-0Pierre-Luc Dubois – 7-7, 50.0, 0-0, 0-0, 0-0Jordan Schroeder – 8-3, 72.7, 7-3, 1-0, 0-0Overall: 569-636 (47.2 percent), ranked 28thSpecial teams units:Powerplay – 0-for-2 at Montreal; 1-for-3 vs. New York RangersOverall: 6-for-57 (10.5 percent), ranked 31stPenalty kill – 2-for-2 at Montreal; 3-for-3 vs. New York RangersOverall: 42-for-51 (82.3 percent), ranked 12thUp next:11/20 – at Buffalo (5-11-4)11/22 – vs. Calgary (11-8-0)11/24 – vs. Ottawa (8-5-6) read more

Patent Nintendos Wii Football Controller

first_img(PhysOrg.com) — Nintendo has come up with yet another idea for an accessory to add to its list of Wii peripherals. This time it’s a soft football-shaped controller that is said to simulate the feel and touch of a real ball when playing football simulation games such as the NFL game, Madden. New World Cup football will unsettle goalkeepers, predicts scientist The football controller holds the Wii remote and another slot holds the nunchuk, which increases the sensitivity of the football. The device also has support for Wii Motion Plus, to improve the controller’s recognition of movements, detect orientation and improve its accuracy.At this stage, the football controller is only at the patent application stage and may not make it to the retail stores, but since there’s already a Wii bowling ball and similar controllers, it may well become available in the near future.More information: European Patent Office, Method and apparatus for simulating games involting a ballvia Siliconera© 2009 PhysOrg.com The football controller is designed to simulate movements during football games, such as running, jumping and throwing. The football is moved quickly from side to side to dodge opponents, and raising the ball simulates a jump. Making jogging motions with the ball is supposed to determine the running speed. Other options are available on the Wii remote, which fits into a slot on the ball. The football also simulates throwing, of course. The player grasps the ball and makes a throwing movement. The direction and power of the throw in the game are determined by the power, angle, force and pitch of the throwing motion. Fortunately, the football has a strap, which should (with any luck) stop players throwing the ball at the TV screen! Explore furtherlast_img read more

FIRST J1419189394036 is an orphan long gammaray burst study finds

first_imgImages of FIRST J1419+3940 at 1.6 GHz with the EVN on September 18, 2018 derived from the two gain calibrations performed in Tianma (original, top, and scaled, bottom). Credit: Marcote et al., 2019. Using a network of radio telescopes, European astronomers have investigated a decade-long transient known as FIRST J141918.9+394036. Results of this study, presented in a paper published February 18 on arXiv.org, provide important insights into the nature of this mysterious source, confirming that it is an “orphan” long gamma-ray burst. © 2019 Science X Network VLA sky survey reveals first ‘orphan’ gamma ray burst Explore further FIRST J141918.9+394036 (or FIRST J1419+3940 for short) is a slowly evolving, extragalactic radio transient. It has decayed in brightness over the last few decades. Recent observations of this object have revealed that it could be an afterglow of a powerful gamma ray burst (GRB) that produced no gamma rays detectable on Earth. FIRST J1419+3940 was therefore classified as the first known “orphan” GRB.However, the fading radio emission from FIRST J1419+3940 could also be interpreted as coming from a new-born nebula powered by a young magnetar. Given that this transient shares similar properties and host galaxy type to the radio source associated with the first known fast radio burst (FRB), FRB 12102, some astronomers assume that FIRST J1419+3940 is a young, rapidly spinning magnetar.In order to verify which of the two hypotheses is true, a team of astronomers led by Benito Marcote of Joint Institute for VLBI ERIC in the Netherlands, has employed the European VLBI (very-long-baseline interferometry) Network to conduct radio observations of FIRST J1419+3940.”To distinguish between these hypotheses, we conducted radio observations using the European VLBI Network at 1.6 GHz to resolve the emission spatially and to search for millisecond-duration radio bursts,” the astronomers wrote in the paper.In result, Marcote’s team found that FIRST J1419+3940 is a compact radio source with a flux density at a level of 620 µJy. With a luminosity distance of about 283 million light years, the size of the source was estimated to be approximately 5.2 light years. Moreover, the observations detected no millisecond-duration bursts of astrophysical origin from this object and confirmed that the radio emission from it is non-thermal.According to the paper, the properties of FIRST J1419+3940 and lack of short-duration bursts from it are consistent with jet expansion from a putative “orphan” long GRB. The researchers noted that although this object shows similar properties as the persistent source associated with FRB 121102, it exhibits significant differences such as much faster expansion and stronger luminosity decay. This disfavors the magnetar birth nebula theory.”A flux density lower than expected is reported, suggesting a faster decline after 2015. This decay could be explained by a change in the post-shock microphysical parameters following the transition to the non-relativistic phase, or by a drop in the ISM [interstellar medium] density (e.g. due to the shock reaching the outer edge of the star-forming region where the GRB exploded),” the paper reads.Although the study confirms the RGB status of FIRST J1419+3940, the researchers noted that it could be still a site of potential FRB production. To verify this, future observations of this source at higher radio frequencies are required. More information: B. Marcote et al. Resolving the decades-long transient FIRST J141918.9+394036: an orphan long gamma-ray burst or a young magnetar nebula? arXiv:1902.06731 [astro-ph.HE]. arxiv.org/abs/1902.06731 Citation: FIRST J141918.9+394036 is an ‘orphan’ long gamma-ray burst, study finds (2019, March 4) retrieved 18 August 2019 from https://phys.org/news/2019-03-j1419189394036-orphan-gamma-ray.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more