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The CEO Performance Review

first_imgaudrey watters Top Reasons to Go With Managed WordPress Hosting Related Posts A Web Developer’s New Best Friend is the AI Wai… Tags:#Analysis#start center_img Being a CEO of a company is, as one CEO recently told me with a certain amount of exasperation and exhaustion, “a 24-hour-a-day, 7 days-a-week job.” It’s all-consuming, all-encompassing, and in many ways when it comes to the success or failure of a company, all-important. But despite the high-stakes involved in being a CEO, it’s a position that all-too-often only receives rigorous feedback and a thorough performance review when things goes desperately awry. And even then, the measurement of “a good CEO” is often merely just a reflection of “good financials.” But surely there’s more to it.Ben Horowitz recently posted a blog post on how Andreessen Horowitz evaluates CEOs. Although he admits, in writing it, it’s also a post that explains what Horowitz himself thinks is important in evaluating (and performing) the job of CEO. Horowitz says he looks at three key areas when evaluating CEOs:1. Does the CEO know what to do?2. Can the CEO get the company to do what she knows?3. Can the CEO achieve the desire results against an appropriate set of objectives?Horowitz divides the first question into two parts: strategy and decision making. In other words, does the CEO know where the company is headed? Horowitz calls this the company’s “story” and contends that while the CEO need not be the person responsible for creating that story, “she must be the keeper of the vision and the story. As such, the CEO ensures that the company story is clear and compelling.” This story will give meaning to the work that staff do but will also align these motivations with key decisions that must be made for the company’s direction. And it’s these decisions Horowitz contends are particularly important: “a CEO can most accurately be measured by the speed and quality of those decisions. Great decisions come from CEOs who display an elite combination of intelligence, logic, and courage. Courage is particularly important, because every decision that a CEO makes is based on incomplete information.”But making a decision only gets you so far, as a CEO must be able to get her company to actually follow through on the decision. Horowitz points to the leadership skills that compel and guide others to accomplish these things as being a fundamental part of what makes a good CEO. In other words, a CEO must build a strong team of capable, motivated individuals. But the CEO must also make sure that those individuals can focus on their work – and on the company’s mission – and not on bureaucracy or politics.Of course, it’s easy to be a rockstar CEO – if you set your standards low enough. And Horowitz notes that there’s a danger for CEOs “succeed” by setting objectives too low, but also a danger of “failing” by setting objectives too high. Horowitz closes by stating that “CEO evaluation need not be a byzantine, unstated art. All people, including CEOs, will perform better on a test if they know the questions ahead of time.” What other criteria would you add to a CEO’s evaluation? Why Tech Companies Need Simpler Terms of Servic… 8 Best WordPress Hosting Solutions on the Marketlast_img read more

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Building With Steel Framing

first_imgInsulating a steel wall has its challengesIf a steel-framed wall is to have cavity insulation, there is still the question of what kind and how it should be installed. Dense-packed cellulose is often placed behind a “scrim,” Morgan says, that’s simple to attach to wood framing but not so easy with steel studs.And if Lombardo is considering the use of fiberglass batts, he’ll find problems there as well. “Fiberglass batts are not the best choice,” he writes. “If you do go in that direction, a standard 14.5-in. batt designed for wood studs will not fit correctly. The batt has to be the full width of the stud bay and must fit into the web of the steel stud which is not so easy to achieve consistently.”Lombardo has read about a technique for wrapping steel framing in “Stud Snuggler” foam to reduce thermal bridging, which might be adapted to a DIY-friendly approach. And Johns Manville’s Spider Custom Insulation, which is blown-in fiberglass, also has possibilities.Moreover, says Dorsett, batts in widths that do fit steel framing area available in both fiberglass and rock wool.But in the end, he says, there’s still the problem of thermal bridging. “There really isn’t a good way around the high thermal conductivity of steel though, even at 24-in. o.c. framing the whole-wall R values will always come in at about half the center-cavity R, whereas with wood studs and R3.2-R4/inch cavity fill the whole wall values come in at something on the order of 75% of the center-cavity value even at 16-in. o.c. spacing,” Dorsett says. If Lombardo could add even more insulation on the outside of the wall — 6 in. rather than the 4 in. he has proposed — he’ll end up with a “pretty decent wall,” Holladay says. “Just remember to keep all of your insulation on the exterior side of your wall framing.”Holladay wrote that cavity insulation in steel framing is “basically worthless” — an assessment that he later admitted was a slight exaggeration — and pointed to comments by Joseph Lstiburek of Building Science Corporation: “Put an R-19 batt in a steel stud wall and you are lucky to get R-5 to R-6 in the real world. That’s equal thermal resistance wise to about 1 inch of rigid insulation installed on the outside of the steel studs.” (For more information from Lstiburek, see “A Bridge Too Far.”)Holladay also pointed to GBA’s own Encyclopedia, which cites a California Energy Commission claim that a steel stud conducts 10 times as much heat as dimensional lumber. The Oak Ridge National Laboratory has found that thermal bridging in a wood-framed wall lowers the effectiveness of cavity insulation by 10%, but performance drops a whopping 55% in a wall framed with steel. Sal Lombardo is planning a new home in the New York-New Jersey area (Climate Zone 5) and is looking at a long list of high-performance construction options: double-stud walls, structural insulated panels, insulating concrete forms, Larsen trusses, and walls built with light-gauge steel framing.Wait a minute. Steel framing, as in the stuff that leaks heat through the building envelope like a proverbial sieve? Maybe, Lombardo says, it deserves another look.“Steel seems like a really good option,” Lombardo writes in a Q&A post at GreenBuildingAdvisor. “Almost unheard of in my area, despite being upwards of 60% recycled, it lasts forever (relatively speaking), is super strong, straight, creates minimal waste, is not affected by termites, pests, or mold, and is equal or close to wood in cost (depending on who you ask).“I know it has very high thermal conductivity. However, there are configurations that can abate this significantly,” he adds, such as a double layer of 2-in. polyiso foam on the exterior.“Why isn’t it more popular?” Lombardo asks. “Am I missing something?”Those questions are the topic for this month’s Q&A Spotlight. Thermal BridgingThermal Bridges Waste Energy A Bridge Too FarGreen Basics: Steel Studs You’ll get a good, but not great, wallAccording to GBA senior editor Martin Holladay, the main problem with steel framing is thermal bridging. Because the effect is so pronounced, all of the wall insulation should go on the outside. Insulation placed in stud cavities won’t accomplish much.“You’re right that it’s possible to install two layers of 2-inch polyiso, giving you R-26,” Holladay writes, “That’s OK, but it’s not great.” RELATED ARTICLES center_img Aren’t we overstating the problem?Lombardo isn’t alone in wondering why steel framing doesn’t get more serious attention.“I am also curious as to why steel hasn’t caught up a little more attention in residential framing in Canada and the USA,” writes Jin Kazama. “I tend to like concrete because of its long-term life. Steel and aluminum are also materials I favor because of the same factor.”Steel framing is very inexpensive when considered from a weight/strength standpoint, he adds. Kazama points in particular to the buildings designed by Blue Sky Building Systems as an intriguing use of steel framing.Referring to research at Oak Ridge National Laboratory, James Morgan writes that the effect of using steel framing is more complicated than the California Energy Commission would suggest. “I could find no suggestion that the tests support omitting cavity insulation,” he says, “and the tests show a pretty good R-20 wall with just 2 in. of continuous outside insulation. If you’re headed for R-30 and beyond, though, I can see why piling foam board insulation on the outside of the wall would ultimately lead to a strategy of leaving the cavity empty — why bother with filling a perfectly good service cavity with fiber to get a measly R-9 or so when you can get the same results by adding another inch or so of polyiso on the outside? But this strategy would apply to a wood-framed wall equally well, once you transition from seeing external insulation as thermal bridge and condensation protection to seeing it as the complete insulation package.”Morgan says that an Oak Ridge National Lab research paper mentions advanced technologies using steel studs that “suggest the potential for a thermally efficient structural alternative to wood framing.” In case of fire, you’re on your ownIn addition to thermal bridging, there’s another problem with steel framing, says Jon Leeth, and that’s what happens in the case of a serious structure fire. “The primary reason I opted not to frame my house with steel was by advice from my insulator (cellulose) who is also a fireman,” Leeth says. “His firefighting perspective was that a burning structure will give fairly reliable clues to structural stability when framed with wood. Metal structures get to that magical temperature where the metal turns very quickly from solid to liquid.“He said as soon as they determine a structure is steel-framed, all firefighting efforts are immediately limited to the exterior of the building. Absolute evacuation and no re-entry aside from human rescue effort. They would not fight the fire on the inside if the building was believed to be evacuated.”Those concerns are echoed by Malcolm Taylor, president of his local fire department. “Houses framed with steel studs still contain all the other combustible structural components and contents that fuel fires,” Taylor writes. “The unpredictable collapse of light steel stud walls is a well known phenomenon. Whether that’s enough of a worry to influence your choice of materials when building a home is another question.” Our expert’s opinionHere’s how GBA technical director Peter Yost looks at the question:When I was at the NAHB Research Center not long after Hurricane Andrew, we had a big light-gauge steel-framing project down in Homestead, Florida. They had a very experienced steel framer as the lead contractor and I was amazed at how fast they were at fastening with tapped screws — not nails — and wielding their screw guns as well or better than I swung a hammer. And their cut list accuracy meant very little framing waste, with what they generated very easy to recycle.So those who think you can’t make steel framing efficient economically I say this: There is a learning curve with any job site change, and switching to steel is simply one of them.Another real advantage of light-gauge steel framing is the ability to gauge to the load; it is a much better use of materials to be able to move from 12 to 25 gauge as the load/application allows. And as a formed material, every framing member is true, every time.But from a hygrothermal standpoint, I can only add — to the excellent points already made regarding energy performance — these two:Condensation. Even small thermal bridging sets up for significant risk of interstitial condensation, exacerbated by the next point.Buffering capacity. This is the amount of water that a material or assembly can “hold” or tolerate without deterioration (for more, see this research paper). Joe Lstiburek is famous for many things, but his “Joe math” attracts a lot of us builder types. Here is one of my favorites: For a 2,000-sq.-ft. home framed with steel, the hygric buffer capacity is about 5 gallons of water; wood-framed, it’s about 50 gallons; and for masonry walls it’s approximately 5,000 gallons.So, when condensation happens in a steel-framed assembly, it’s the really low hygric buffer capacity that ramps up the significance of that condensation. The wall may have very little tolerance for that moisture.My conclusion: if you are considering light-gauge steel framing, use the BSC “perfect wall” approach. Keep all of your R-value to the exterior, and let that steel be part of the interior conditions (or nearly so) of the building. And the more severe the climate, the more stringent my recommendation is.last_img read more

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Practical Design Advice for Zero-Net-Energy Homes

first_imgQ. When your heating and cooling loads in a net-zero home are already smaller than the capacity of anything but a single wall-mount ductless minisplit, how do you balance correct sizing with adequate distribution?Answer 3 — Leigha’s question in Comment #17 is a variation of the first question in a climate that will need cooling as well as heating. The house sounds like a single-story. With the bedrooms to the north in this very well insulated passive solar house, I’m assuming that they don’t have a ton of glazing, which in this case drives heat gains from the sun, as well as heat loss. So I might be comfortable using just a single unit in the main space if the occupants understood that the bedrooms will be cooler than the main space in winter and warmer in summer, and if the rooms met my 1,000 BTU/hr criterion mentioned above.Having said that, the system you mentioned that incorporates a wall cassette for the main space, and a ducted unit for the bedrooms would be a step up in occupant satisfaction for many people, because the bedrooms are now able to have their own setpoint. A ducted unit with the temperature sensor built into the air handler (the stock setup) averages the return temperature from the bedrooms to decide how much heating or cooling to provide. You also have the opportunity to incorporate some good filtration in that system. MARC’S ONLINE COURSE Interested in learning more? Since 2012, I’ve been working with NESEA and HeatSpring to teach an online course as part of NESEA Building Energy Master Series with other experts from the NESEA community. Over 150 professionals have taken my Zero Net Energy Homes design course, and the next course starts on February 3rd. This course is an opportunity to study with me: to ask me questions for a full ten-week semester. You will walk away with a comprehensive understanding of all of the key components of a zero net energy home — envelope, systems, and renewables — and how they fit together, with key pitfalls to avoid, and numerical calculators for sizing peak heat loss, glazing amounts, annual energy use, and solar electric systems that will empower you to confidently design a zero-net-energy home. Successful students will actually do a full design of a zero-net-energy home, and earn NESEA’s Zero Net Energy Homes Professional Certificate. The course is approved for 12 AIA CEUs + 6 MA CSL credits (1 hour for Code, 1 hour for Workplace Safety, 1 hour for Business Practices, 3 hours for Energy).If you’d like to see some free content from the course, you can sign up for a free test drive of my course here, or check out a free 26-minute video lesson here. Q. How exactly are these companies determining the capacities of these units? Is there a way to actually calculate, or even estimate, how much heat these units will actually output at -13°F?Answer 5 – On ratings and Rheannon’s question in Comment #14: the only way through this is to get published engineering heating capacity from the manufacturer and then vet it through their representatives. If there are contradictions, pursue them until you are satisfied or until you reach a point where your confidence is so shaky you abandon consideration of that product.For example, Dana mentions the Daikin Quaternity, and yet I can’t seem to ever find a capacity table below 14°F. That’s not low enough to make me comfortable in specifying it. I know some Daikin VRF machines have been observed operating at -15°F, and I’ve seen the Mitsubishi Hyperheats operating at -22°F at a school in west central New Hampshire. In Zones 6 there are increasing numbers of these heat pumps being installed. (We did some Fujitsus north of the White Mountains this year.) In Zone 7, I’d be looking at some backup heat. It all depends on the client’s appetite for risk. Say a 120-square-foot room has contact area through the floor with a heated room. (Let’s assume that the room under consideration is above the heated room.) Let’s assume that the room has 150 square feet of wall area that faces the upstairs hallway, which we’ll assume is open enough to the first-level heated room that it is at the same temperature as that room.Each of those areas is has a thermal resistance of about R-3. So there is a UA of (120+150)/3 = 90. This is a room with a pretty high area of contact with the heated room. For every °F difference across these assemblies, there is 90 BTU/hr of heat transferred. Say you want that room to be 68°F when the heated room is 71°F. The available heat transfer is 270 BTU/hr.If the room to be heated has a 15-square-foot window that has a U-factor of 0.2 (a good triple-glazed window) and a wall area to outdoors of 150 square feet with a U-factor of 0.03, a ceiling of 120 square feet with a U of 0.02, and an air leakage rate of 4 cfm, then the room UA to outdoors is (15×0.2 + 150×0.03 + 120×0.02 + 4×1.08) = 14.2 BTU/hr.If we divide 270 BTU/hr by 14.2 BTU/hr, we find that (when the room is unoccupied) there is an energy balance when the indoor/outdoor temperature difference is 19 F°. With a desired indoor temperature of 68°F, that’s 49°F outdoors. Not impressive — and this is a superinsulated house.Now, add some internal gains and things change. Put a person in there with an iPad and maybe an LED reading light and you more than double the available heat, and now you have a balance at 45°F to 50°F outdoors. But if you’ve been gone all day, and it’s been 30°F outside, you’re not coming into a warm room if you left the door closed.What about if it’s open? That helps a lot. How many cfm move through an open door? I think it’s different depending on where the door is. If it is up a floor, it has more air flow through it than if it is on the same level — the difference in height between the heated room and the door opening helps that movement of air and energy. I noticed this recently in a house with a minisplit in the main living space, and an open door to an adjacent bedroom, and open doors on the second floor to two other bedrooms. The first-floor bedroom was noticeably colder. It had less conductive contact area too, and more exterior area, so all things weren’t equal; but it was striking how much cooler it was. (The main level was 72°F, the upstairs rooms were 68°F, and the first floor room was 63-64°F.)I tend to think of an open door as being equal to a decent bath fan — it’s worth 50-100 cfm. So at the low end, 3°F temperature difference buys you 150 BTU/hr, and at the upper end it’s double that.So Aaron’s 3,000 BTU/hr bedrooms aren’t going to be heated by a point-source heater, at least to satisfy most people’s comfort criteria. My guideline is that if people will tolerate 4°F lower than the heated space (which in my mind means 72°F heated space, 68°F bedroom) and they leave the doors mostly open, then a point-source heater is viable when the heat loss is 1,000 BTU/hour and the room is occupied; 1,500 BTU/hr is kind of my soft cut-off for considering it. Beyond that, I’ll provide some electric resistance backup in those rooms.A couple of other thoughts to confuse the issue:How hot is the heater? The plume of very hot air off a wood stove creates a significant layer of very warm air at the ceiling level that drives more conduction and more convection. A wall mounted minisplit is the opposite extreme (well, maybe a radiant floor is) because it mixes the air in the room and there is little stratification.Who is going to live there? In speculative development with multiple units, there will be someone who hates you because you didn’t put heat in their room. I speak from experience.Cooling is harder. A cooling source on the main floor won’t cool the upstairs. Tidbits on some of the rest of the posted questionsMachines that offer separate sensible cooling and humidity setpoints almost always will do that at a cost in efficiency, because to maintain a relative humidity setpoint without over-cooling a space they will use some form of reheating the air. This means they cool the air down to wring the moisture out, then heat it back up to avoid over-cooling.They may do this cleverly — like using the rejected heat of the compressor for reheating — but this is not an efficient operating mode. It may be more efficient than operating a separate dehumidifier, but the two options would need to be carefully compared to make that determination. I know from experience that using the Dry mode in the Mitsubishi VRF equipment uses more energy than running that equipment in the Cooling mode.I would tend to agree with Dana that most buildings with minisplits won’t need additional dehumidification, but there are always conditions where there is no cooling load but there is a moisture load, and if you can’t tolerate occasional excursions out of the ASHRAE comfort envelope (60% RH limit, if I recall correctly), then you need some independently settable humidity level. Scott, the best way to assess whether the minisplits work well in Dallas is to ask people who have been using them in similar applications to yours.On point-of-use demand electric water heaters: Say you start with 45°F water and want a 1.5 gpm shower at 110ËšF — that load is just a smidgen under 15 kW, or 60 amps. So you need to consider electrical panel capacity first.By comparison, a typical electric tank type water heater is 1/3 of that. You can buy the demand heater for about half the cost of a really well insulated electric tank type, and installation is probably a bit lower in cost. If you need two demand heaters, probably there aren’t savings over the tank type and no worries about trying to take a shower when someone starts the dishwasher or clothes washer or just turns the kitchen sink tap wide open.When might a point-of-use electric be a reasonable choice? Small urban single-occupancy units where the laundry is in the basement. Basically, when only one person needs to decide which uses to satisfy with the single unit.On EcoCute machines (Japanese air-to-water heat pumps): Yes, it would be great to get them into the U.S. I wonder if the barrier is a refrigerant that operates at 1,500 to 2,000 psi — What will UL say about that? First of all, thank you very much to all of you who contributed to this thread. I agree with all of you completely.☺ Remember, the reason Internet discussions are so acrimonious is because the stakes are so low…Last week, I published an article titled “Minisplit Heat Pumps and Zero-Net-Energy Homes” on GBA. At the end of the article I asked readers to submit questions on topics that they’re looking to learn more about so I could provide a “mini-consultation” and answer their question while hopefully helping others with the same questions. Here are answers to the five questions that I picked. Here’s another approach: do the whole house as a single-zone ducted system. With a strongly passive solar design, the whole-house ducted system can serve to redistribute air from the warmer side of the house to the bedrooms.As to limits to the length of ducts: these units don’t have the static pressure capability of traditional American central forced-air systems, so looking carefully at the unit specification is important, as well as good duct design. For example, Mitsubishi’s SEZ air handler (used on the Mr. Slim models) has a top setting of 0.20 inches of external static pressure — that’s low! The Fujitsu RLFC series has a capability of 0.36 inches on the smaller air handlers, and lower on the largest one in that series. So you have to check. Q. Our current energy load calculations show around 50,000 BTU/hr for heating and cooling. We were considering forgoing cooling, but with the Daikin Altherma system we could possibly have it as an added bonus to domestic hot water and radiant floors. Unfortunately, the initial cost has us leaning towards a condensing gas water heater.Answer 4 – Eric’s question in Comment #4 is about the economics of comparing a gas condensing water heater with a Daikin Altherma, which can also drive a radiant floor and make domestic hot water, and can provide chilled water for cooling in the summer. Before I address this, may I comment that a design load of 50,000 BTU/hour for a house measuring 2,100 square feet in Zone 5 seems way high — at 24 BTU/hr/sf, maybe even higher than a code-minimum home today. My quicky guideline that I tell people is to set a target of 10 BTU/hr/sf in Zone 5. So make sure your load has been properly calculated; and if it has, first spend your money on reducing that load.It sounds as though the base solution of the gas water heater has no cooling, but even though the Altherma offers it, you don’t need to implement it, especially since it means a second distribution system — added to the quite costly concrete/steel floor hybrid, you’ll need a ducted system for the cooling.To begin looking at costs and benefits, you need to compare fuel costs. If the gas available is natural gas at current fuel prices (let’s say $1.25/therm) and the heater operates at 90% efficiency, then the heat costs about $14/million BTU. Say your electricity costs are $0.15/kWh. To get the same cost per BTU, the Altherma needs to operate seasonally at a Coefficient of Performance of about 3 — three units of heating for every one unit of electricity used. I don’t have data on Altherma units other than a couple of retrofits with very extenuating circumstances, but from the published engineering data I think an annual COP of 3 in Zone 5 in a low temperature hydronic radiant system is plausible.So at that point you’ve spent more in capital cost than the gas system for similar annual cost.What the heat pump offers you is the possibility on making your own energy with onsite renewables, which you can’t get with the gas. Buying the renewables is a separate economic decision: What does electricity cost where you live, what’s the history of price inflation, what are incentives beyond the Federal 30% tax credit, etc.? The prices on solar electricity continue to drop, the systems are long-lived and reliable, and you’re investing in your own energy source. And even if you choose the gas heating system, you’ll still be using electricity, so that choice doesn’t preclude using onsite renewables; it just makes it hard to get all the way to net zero.But please first work on getting that 50,000 BTU/hr down…If it’s OK, I’m going to pull Peter’s question in Comment #9 into this, because he asks to compare minisplits with ground-source heat pumps (GSHPs). Peter, I approach this question in two different ways. The first is to recount some analysis done by the team who designed the Putney School’s 16,000-square-foot Net-Zero Field House. Being in southern Vermont, they felt that air-source heat pumps were perhaps on the edge of their applicability.Fortunately, the HVAC engineers Kohler & Lewis from Keene, New Hampshire, had switched their office building to minisplits a couple of years earlier and had seen their system operate down to -15°F even though there was no published data at those temperatures. And then Andy Shapiro led the team through an interesting analysis. They asked, if the GSHP system could truly achieve a full point of COP higher than the minisplits (I can’t recall what values they picked for the two COPs, just that they were separated by 1!), what would the cost be of each heat pump system plus the cost of the solar electric system necessary to provide the energy consumed by the heat pump system? (In essence, the cost of the heating system cost plus its associated fuel cost over the years.)If I recall correctly, the minisplits, even after conceding a higher COP to the GSHPs, came in something like $4/square foot less than the GSHP system and the smaller associated solar electric system. And as Dana said in his post, we now have some really excellent hard field data about the COP of minisplits in cold climates that is really encouraging.The second way I approach your question is to say that one thing I really like about the minisplits is how they are packaged systems from a single supplier, and are highly engineered as a system and therefore very reliable. GSHP systems are, at least where I have practiced, essentially custom engineered and installed, usually by several entities who have a shared responsibility to make sure the systems perform. Knowing that this will cause howls of au contraire to arise, I will say that GSHPs have been the most problematic HVAC technology I’ve worked with, and so I choose the Japanese air-source equipment without a second thought at this point (and I have worked with GSHPs on projects ranging from zero-net-energy homes to buildings up to 70,000 square feet). Q. How do you decide when ducted minisplits (rather than ductless minisplits) are worth the time and expense to install them?Answer 1 — I’d like to combine the questions included in Comments #1, #5, and #13. The essence of the question is: When do we have to transition from a point-source heating strategy to a strategy that provides each room with its own source of space conditioning? (I say space conditioning because we may ask this question just as well about providing cooling.)The first question we should ask is, are doors open or doors closed? And a subset of “doors open” might be a small transfer fan moving air from a warmer space where a heater is located to a room without a heater. (Robb Aldrich at Steven Winter Associates has done great work on this strategy.) Let’s look at “doors closed” first. RELATED ARTICLES Rules of Thumb for Ductless MinisplitsJust Two Minisplits Heat and Cool the Whole HouseHow To Buy a Ductless MinisplitBruce Harley’s Minisplit TipsMinisplit Heat Pumps and Zero-Net-Energy Homes Ductless Minisplits May Not Be As Efficient As We Thought Long-Term Monitoring of Mini-Split Ductless Heat Pumps in the Northeast Q. The thermostat for our Mitsubishi ducted system only goes down to 63°F. Do you know of any way to reset the thermostat to have a lower minimum temperature?Answer 2 — This question is an easier one. In Comment #12, Eric asked about his four-year-old Mitsubishi multi-zone system and how to set the temperature lower than the 63°F limit. Today we’d use the controller Honeywell provides to Mitsubishi, the MHK, which allows communication over the Web, and much wider setpoints. I re-confirmed today with Mitsubishi engineers that this control is unfortunately not retrofittable to the older system.So my suggestion is that you try just shutting the second floor ducted system down at night completely, and let the main floor wall cassette do the work overnight. This would work well when you’re away for a longer period of time.Another way, perhaps a bit cumbersome, is to figure out a way to put a tiny bit of heat right at the thermostat and fool the sensor into thinking it’s warmer than it really is. We’re talking about two bulbs worth of Christmas lights… or mount your iPhone charger right below the thermostat overnight.As to your question on the flexible duct work — flex duct has a bad rap because it’s easy to install so badly. In your case, where the runs are short, it virtually assures you that there is very little duct leakage, and it’s not long enough to cut down on the air flow unless it’s been installed such that it is crushed or otherwise improperly installed. I’d leave it, as long as the rooms being served are being adequately heated and cooled. (Disclaimer: I just put flex duct in my own system — using a 5 or 10 foot flex duct runout to the register boot makes the system quiet — just stretch it out and don’t crush it.) Marc Rosenbaum is the director of engineering at South Mountain Company on the island of Martha’s Vineyard in Massachusetts. He writes a blog called Thriving on Low Carbon and teaches a 10-week Zero Net Energy Home Design course as part of the NESEA Building Energy Master Series, you can test drive the course for free here.last_img read more

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Your Chance To Hang Out With The Stars At The 2015 Necker

first_imgA new auction hosted by CharityBuzz is giving you the chance to bid to be a part of The 2015 Necker Open with Sir Richard Branson, Greg Norman and Special Guests Chevy Chase and Dave Feherty!The winner of the auction will have the chance to play in the Necker Open Golf Pro-Am, have a half hour private lesson with Greg Norman and hop on a private jet to Necker Island with Chevy Chase.Team up with Greg Norman and other PGA Tour Legends to compete in this fun, spirited golf event across world-class golf courses and the wonderful backdrop of the British Virgin Islands.Your journey will begin with 2 nights and 36 holes and will also include a 1/2 hour private golf lesson with Greg Norman at the Lodge at Sea Island, along with Special Guests Dave Feherty and Chevy Chase.You will then be whisked away by private jet along with Chevy Chase to Necker Island for 3 nights of relaxation, parties and fun with Host Sir Richard Branson and the “Necker 9” golf challenges.Each of the 12 spots includes all-inclusive accommodations and private air transportation for two.The auction will benefit the Greg Norman Foundation and the Marilyn G. Rabb Foundation.To find out more about the auction and make a bid, click here.last_img read more

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