Over the past two weeks I’ve written about two relatively obscure passive solar heating strategies: isolated gain using sunspaces; and indirect gain using a Trombe walls. This week I’ll cover a far more common and cost-effective approach: direct-gain.Direct-gain passive solar systems rely on south-facing windows to bring solar energy directly into a house. That sunlight is absorbed by materials in the house (the floor, walls, furniture, etc.), which warm up, store some of that heat, and re-radiate it back into the room, warming the space.One way of looking at this is that the house itself serves as the solar collector and heat-storage system. There are no fans or pumps to move heated air or water around. The systems are silent, trouble-free, and easy to maintain — by washing windows and, in some cases, opening and closing window blinds to adjust incoming solar gain.The thermal storage function is most effective with high-mass materials, such as tile or concrete floors, fireplaces with brick or stone facings, and tinted plaster walls. These materials keep the space from getting too hot during the day, and they continue radiating warmth into the living space in the evening.The key to success with direct-gain passive solar heating is to provide the right amount of south-facing glass area and to couple that glass with adequate thermal mass. If too much glazing is installed, the space will overheat on sunny days. The better insulated the house, the less glazing can be installed before overheating becomes a concern.Back when I was involved in passive solar energy in the late-1970s in New Mexico, there were lots of examples of houses being built with the best of intentions, but with way too much south-facing glass. They were like greenhouses on sunny days and, because the glazing was only double-glazed without low-emissivity (low-e) coatings, there was a lot of heat loss through that glass at night. The houses greatly fluctuated in temperature.As we’ve learned more about the energy dynamics of homes, we’ve learned that it makes sense to use higher levels of insulation with reduced glazing areas. Better-insulated houses don’t require as much solar gain to provide a significant fraction of the heating needs, and the careful balancing of insulation, glazing, and thermal mass can avoid those temperature fluctuations that were such a problem in the past.To do this requires advanced energy modeling software. Fortunately, such programs are readily available today, including Energy 10, Energy Plus, and REM Design. These programs account for insulation levels, window area, glazing type, and thermal mass. Don’t consider designing a direct-gain, passive-solar house today without using such a modeling program; make sure your designer has access to such capabilities. This is key to success.In addition to this Energy Solutions blog, Alex contributes to the weekly blog BuildingGreen’s Product of the Week, which profiles an interesting new green building product each week. He is founder of BuildingGreen, Inc. and executive editor of Environmental Building News. To keep up with his latest articles and musings, you can sign up for his Twitter feed.
Sign up for a free trial and get instant access to this article as well as GBA’s complete library of premium articles and construction details. One of the presentations I attended at the Passive House conference in Portland, Maine, on September 22, 2014 was a session called “Passive House certifiers’ roundtable.” The first speaker on the panel, Tomas O’Leary, explained that he usually charges about $2,200 to certify a residential Passivhaus project. He warned the audience that certification is “quite an effort; don’t underestimate it.”Tomas advised that anyone interested in certifying their Passivhaus should remember the following important steps:Is each one of these details really essential for determining whether a house can be certified as a Passivhaus? Absolutely.If you are in any doubt about this issue, remember that one of the cited causes of the famous divorce between the Passivhaus Institut in Germany and Passive House Institute U.S. was a dispute over the details of the certification documents for a house in Canada. The dispute centered on two points: whether the efficiency calculations for a Canadian HRV met the strict efficiency calculation requirements specified by the German institute; and whether an evergreen tree was tall enough to invalidate the shading calculations entered into PHPP.I admire energy nerds who use THERM modeling for all kinds of complicated building assemblies. I really do. We can learn a lot from THERM modeling calculations.I’m grateful that someone has made the calculations to determine that in-betweenie windows perform slightly better than outie windows. Now we know.I’m also grateful that Stephen Thwaites and Bronwyn Barry are available to explain the subtle differences between the way window U-factors are calculated in Europe and the way they are calculated in North America.But when I hear lengthy discussions on these issues, I sometimes think we’ve fallen down the rabbit hole. If you are a builder or a designer rather than a building scientist, it may… This article is only available to GBA Prime Members Start Free Trial Already a member? Log in
Globe Business launches leading cloud-enabled and hardware-agnostic conferencing platform in PH View comments John Lloyd Cruz a dashing guest at Vhong Navarro’s wedding Read Next PBA IMAGESFor once, it was the other Aguilar, who shone in the spotlight.The seldom-used Raymond Aguilar provided Barangay Ginebra a big lift on Sunday, helping the Gin Kings snap their three-game slide after a 100-96 win over the June Mar Fajardo-led San Miguel Beermen.ADVERTISEMENT Don’t miss out on the latest news and information. LATEST STORIES Slow and steady hope for near-extinct Bangladesh tortoises NEXT BLOCK ASIA 2.0 introduces GURUS AWARDS to recognize and reward industry influencers Typhoon Kammuri accelerates, gains strength en route to PH Aguilar finished with 16 points and made such a big impact in close to 30 minutes of action that his head coach Tim Cone couldn’t stop himself from raving about the former National University slotman’s performance.“I can’t talk enough about Raymond Aguilar — the other Aguilar, for once. He was just phenomenal,” Cone said.FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSLillard, Anthony lead Blazers over ThunderSPORTSMalditas save PH from shutoutWith Cone not putting Japeth Aguilar as Fajardo’s primary defender in a move to keep him from getting into foul trouble, the tall order of defending the reigning four-time MVP was now on Raymond.And the 32-year-old big man went on to defy his coach’s expectations and gave Fajardo all he could handle while also giving a boost offensively. MOST READ 2 ‘newbie’ drug pushers fall in Lucena sting Trending Articles PLAY LIST 00:50Trending Articles00:50Trending Articles00:50Trending Articles01:29Police teams find crossbows, bows in HK university01:35Panelo suggests discounted SEA Games tickets for students02:49Robredo: 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 City Kammuri turning to super typhoon less likely but possible — Pagasa Fajardo shrugs off SMB’s first loss “He guarded June Mar all game long. We didn’t want to put Japeth on June Mar because we didn’t want Japeth to get in foul trouble, so that chore went to Raymond. And then, he hit big shots and made big plays on his own,” he said. “It was amazing. He played out of his mind tonight and I can’t thank him enough at this point because we really needed a big game from somebody.”Aguilar’s breakout performance was just the kind of game Cone needs from the Gin Kings, especially with the team cautious in breaking in Greg Slaughter back from his injury.“The good thing about what we’re going through now is we’re developing trust in guys that we’re not used to trusting. Guys like Raymond are stepping up and playing big for us,” he said.ADVERTISEMENT Brace for potentially devastating typhoon approaching PH – NDRRMC
US President Donald Trump speaking during a visit to the Israel Museum in Jerusalem Trump will recognize Jerusalem as Israel’s capital on 6 December 2017, upending decades of careful US policy and ignoring dire warnings from allies across the Middle East and the world. AFP file photoPresident Donald Trump will recognise Jerusalem as Israel’s capital Wednesday, upending decades of careful US policy and ignoring dire warnings of a historic misstep that could trigger a surge of violence in the Middle East.A senior administration official said Trump would make the landmark announcement-which flies in the face of warnings from America’s allies across the region and the world-at 1 pm (1800 GMT) from the White House.“He will say that that the United States government recognizes that Jerusalem is the capital of Israel,” a senior administration official said, speaking on condition of anonymity.“He views this as a recognition of reality, both historic reality,” the source added, “and modern reality.”Plunging further into a bitter centuries-old argument between Jews, Muslims and Christians, Trump will also order planning to begin on moving the US embassy from Tel Aviv to Jerusalem.“It will take some time to find a site, to address security concerns, design a new facility, fund a new facility and build it,” the official said, indicating that the move will not be immediate.“It will be a matter of some years, it won’t be months, it’s going to take time.”The status of Jerusalem is a central issue in the Israeli-Palestinian conflict, with both sides claiming the city as their capital, and expectations of Trump’s announcement have roiled the combustible region.In a frantic series of calls on its eve, the leaders of Saudi Arabia, Egypt, Jordan, the EU, France, Germany and Turkey all warned Trump against the move.Anticipating widespread demonstrations, US government officials have been ordered to avoid Jerusalem’s Old City and the West Bank.But Trump’s move comes close to fulfilling a campaign promise and will delight his political donors and the conservative and evangelical base that is so vital for the embattled president.‘Red line’Most of the international community does not formally recognize Jerusalem as Israel’s capital, insisting the issue can only be resolved in final status negotiations.US officials talk of “threading the needle”-fulfilling Trump’s campaign pledge, while keeping the peace process on the rails.The White House argues that such a move would not prejudge final talks and would represent the reality that west Jerusalem is and will continue to be part of Israel under any settlement.“President Trump remains committed to achieving a lasting peace agreement between the Israelis and the Palestinians and is optimistic that peace can be achieved,” a second official said.“President Trump is prepared to support a two State solution… If agreed to by the two parties.”But critics say Trump’s approach is more like “splitting the baby” and could also extinguish his own much-vaunted efforts to broker Middle East peace while igniting the flames of conflict in a region already reeling from crises in Lebanon, Syria, Iraq, Yemen and Qatar.The armed Islamist Hamas movement has threatened to launch a new “intifada” or uprising.Saudi Arabia’s King Salman warned his close ally that moving the US embassy was a “dangerous step” that could rile Muslims around the world.“Mr Trump! Jerusalem is a red line for Muslims,” Turkey’s President Recep Tayyip Erdogan said in a raucous televised speech, echoing alarm expressed by Palestinian and Arab leaders.‘Embassy Act’Israel seized the largely-Arab eastern sector of Jerusalem during the 1967 Six-Day War and later annexed it, claiming both sides of the city as its “eternal and undivided capital.”But the Palestinians want the eastern sector as the capital of their future state and fiercely oppose any Israeli attempt to extend sovereignty there.Trump was pushed to act on the embassy as a result of the 1995 Jerusalem Embassy Act, which stated that the city “should be recognized as the capital of the State of Israel” and that the US embassy should be moved there.An inbuilt waiver has been repeatedly invoked by successive US presidents, postponing the move on grounds of “national security” once every six months, meaning the law has never taken effect.Several peace plans have unravelled over the issue of how to divide sovereignty or oversee sites in the city that are holy for Christians, Jews and Muslims.
Laura Skelding: O’Rourke/Douglas Young: Cruz (For The Texas Tribune)U.S. Rep. Beto O’Rourke, D-El Paso (left), and U.S. Sen. Ted Cruz (right).Congressman Beto O’Rourke said Monday he and U.S. Senator Ted Cruz, will not debate this Friday, August 31.Earlier this summer, the Cruz campaign proposed five debates – all on Fridays – with the first to take place in Dallas on August 31.Congressman O’Rourke (D-TX), who is running against Cruz in the Senate race, spoke at a forum in Austin.“One of the challenges we’ve had is that Senator Cruz not only attempted to dictate the date, the place the time, um, also the moderators, the subjects that we could and could not talk about. The furniture on the stage…,” the Democratic Representative from El Paso commented.Still, O’Rourke said he’s confident Cruz and him will come to an agreement and added he would be happy to debate on Saturday or Sunday to accommodate Cruz’s Senate schedule. Share