Posts Tagged ‘green buildings’
Florida’s new commercial energy codes
Florida's 2010 Energy Code-Part II Here are my notes from reviewing the new 2010 Florida Energy Code. Just like the new residential energy code, the commercial energy code for 2010 calls for significantly more energy efficient buildings. This trend will likely continue in subsequent codes as well. For new construction here are the values in Table 502.1.1.1: Roof insulation-R-40 Walls: R-30 (quite a jump from before!!!) Walls are required to have an absorptance of 0.3 or less. Floors above grade: R-30 Windows: U- value of 0.45 or better (the lower the U value, the better). This means quality double pane windows. Window Tinting (SHGC): 0.25 or less for 1% to 40% window/wall ratio (that is a high level of tint) 0.19 or better for 40% to 50% window to wall ration (examples of 0.19 tint would be dark tint or reflective tints) window to wall ratios above 50% are not allowed without specialized modeling to prove ...
Advanced Energy Efficiency for Buildings
ASHRAE (the American Society of Heating and Refrigeration Engineers) is in the process of releasing booklets free to all interested people with practical step by step information that makes a building design save a projected 50% of the energy bills of conventional buildings being designed. To keep things simple, ASHRAE dedicates each booklet to a specific type of building: small offices/retail/warehouses/motels/educational/smaller healthcare facilities. These booklets are part of a long term commitment by ASHRAE to help create a world where buildings use dramatically less energy. The first stage was to release booklets that describe step by step information on how to save 30% on energy buildings being designed. I had mentioned these booklets on my home page. The new stage is 50% energy reductions. So far one free booklet is available in this category (for small offices). By the time you read this, there will probably more types of buildings available. In the future, expect guidelines for even higher energy targets. By the time 100% energy savings is a reality-buildings will likely need to be linked together with surrounding buildings in terms of energy features (like co-generation, waste heat recovery etc). ASHRAE (the American Society of Heating and Refrigeration Engineers) is in the ...
Using the ground for Geothermal in Florida
When the ground gets used for storing and discharging temperature, the whole energy transfer becomes pretty complex. Below is a great schematic I found on a NASA website describing global warming. Among other things, this illustration shows all the energy transfers that effect the upper surface of the ground. With respect to geothermal air conditioning, we would add to this energy diagram with our piping system of course. [caption id="attachment_150" align="aligncenter" width="478" caption="Energy Transfer at earth's surface (from NASA)"][/caption] This illustration was produced to help explain global warming. Notice anything strange? As a mechanical engineer, we were taught in engineering school to define boundaries of whatever we are studying and include all energy within the boundary and crossing the boundary. So I am calling attention to energy transfer from the center of the earth the the earth's crust. It is not represented in the above illustration. I have not found any information on this subject that a non-astro-geophysicist type like me could understand, but that doesn't mean it isn't important. If any readers out there can enlighten us on the core of the earth's exact contribution to soil temperatures, please do. Anyway, ...
Green Gardens-pest control
Thanks for all the feedback on the Edible Garden blog. Today's blog follows up on the topic of edible landscapes and the concept of green buildings. FIRE ANTS IN FLORIDA Florida has an abundance of pests. Fire ants are a nuisance around buildings. Actually, I got bit by fire ants a few times in my bed, sleeping at night! The ants had gotten inside the house and considered the area below the carpet as a freeway system all around the house. At any given time, I can find about a dozen fire ant nests around my house and inside my garden. One has to admire their persistence. Did you know fire ants can communicate during the defense of their nests in such a way that all the ants bite at the same time? I found this out the hard way when I was brand new to Florida and didn't know what fire ants were. Out of curiosity, I have torn apart fire ant nests and found as many as 10 queen ants in the nest. I dug one nest out and found it was about 28" deep. I have never been able to eliminate fire ants for any length of time, ...
How Geothermal is Different in Florida
As geothermal air conditioning and heating gains popularity; a large and sometimes confusing amount of data is surfacing regarding geothermal techniques. I get asked a fair amount about what types of geothermal systems and I also hear a few reports of geothermal-gone-bad. To help clarify why Florida has a unique geothermal system compared to other parts of the US-- let's start above ground. Climate-wise, Florida has far more cooling demand than heating demand. This has a double impact. First, geothermal systems during a Florida summer pump more heat into the ground than they take out in winter (for space-heating purposes). This tends to make geothermal systems relying on surface temperatures unstable through time. Second, the winters in Florida are short and mild to the point that they are not able to "recharge" the ground temperatures. This is not to say that there aren't a few buildings in Florida with relatively matched heating and cooling loads though. I am referring here to buildings that use a lot of hot water for industrial processes or domestic purposes (such as factories, heavily used kitchens, and laundrymats). Cases like this warrant special consideration. Now, let's look below ground and see what else makes Florida different geothermally. The second thing that makes Florida unique geo-thermally ...
digitally controlled lighting
What an amazing step forward with lighting! Intelligent lighting that senses occupancy and daylight and varies the lighting output hour by hour automatically. The best part is, it can somehow digitally alter the lighting output of the fixture to keep it from overlighting the space. Oh happy day! For years I have input lighting designs from various electrical engineers into the State's energy forms. It is amazing how often lighting designs flunk the energy code. I am sure many still wind up getting built never-the-less. It is not uncommon to find older buidings with 1-1/2 times to twice as much light as they need. Imagine an office needs 143 watts of light. The electrical designer looks at light fixtures which are available in 120 watt or 200 watt increments, and so the office gets (2) 120 watt fixtures (that's 240 watts in an application that only needs 143 watts). With this new system now, factory-set lights can take these two light fixtures and make sure they don't exceed something in the vicinity of 143 watts. This alone is big news. Now imagine the office has a window. The window provides ample amounts of daylight into the space during typical work hours-say for example 20 ...
wind energy in Florida?
I have been watching the wind here in Lakeland, Florida to see if wind energy might be worthwhile for my green office. Does anyone have experience with wind energy in Florida? I found plans to make a simple wind generator basically using a common fan but only found the local winds spinning the fan blades periodically, and not that fast at that. By increasing the size of the fan blades, it seems that the generator could respond to lighter winds and have more intertia to keep spinning a little longer. But I still have doubts the whole project would be successful. What I noticed was I get a steady balmy breeze with occasional gusts. This is typical for most days of the year. I suspect the trade winds ramming into Florida might have something to do with this. Florida's beaches have an advantage breeze wise, but is that enough? Anyway, I found an intriguing concept on YouTube called "Bendini Motors". Basically, I think this entails modifying a conventional DC motor so that it pulses energy at strategic points when the coils spin around. I watched how a small PC fan would spin for a long time after someone flicked ...
programmable thermostats
[caption id="attachment_31" align="alignright" width="112" caption="Guy Van Meulebrouck"][/caption] I just found a 2010 survey from Lawrence Berkely National Laboratories regarding how programmable thermostats actually wind up being used by occupants. The study reported a survey of 81 residential thermostats and found the following: • 45% were in hold • 30% were programmed • 10% were manual thermostats (not programmable) • 5% were off • 10% operational status was not visible in the picture. The complications involved in each particular thermostat's programming are evident here. I envision a thermostat in the future that uses user friendly computer software and then transfers information to the thermostat via a USB memory stick. The same innovation would be welcome for sprinkler timers too! I used to specify Honeywell T7350's as a general practice. These which are challenging to program correctly due to the immense features. It took me two tries to get my own T7350 programmed right. The local Honeywell representative assured me that he pre-programmed the thermostats himself before he delivered them to jobsites. Great idea. He welcomed me adding information on my drawings as to specific settings that were needed for the building. Guy Van Meulebrouck PEconsulting engineerguy@guyvanmconsulting.com10947 ...
Size of Floridian Aquifer
a>Today's blog is #5 in a series dealing with geo-thermal heating and cooling's impact on Florida's aquifers. I have seen impressive projections on the possible growth of geothermal in coming years and I would agree geo-thermal is a superior system for many building types in Florida. But what will happen to our aquifer in the future as more and more buildings commuicate with the aquifer from a thermal standpoint (pumping water out and back into the aquifer? I looked a map of the Floridian Aquifer.. The aquifer is reported to span some 100,000 miles of subsurface area and typically experiences a 10" to 12" per year recharge. This huge volume of water has to be taken into account. The weight of water in all of Florida's aquifers is perhaps unknown but by doing simple calculations on the area and recharge rate, it is easy for me to see the Floridian Aquifer alone could be into the trillions of pounds of water. There are other aquifers of note in Florida too, like the Hawthorne Aquifer. I cannot imagine how much heat would have to be rejected into the aquifer and how many pounds of metals would have to be added to significantly impact ...
What is Geo-thermal?
What is Geo-thermal? Geo-thermal is a process of using the stable temperatures within the earth to benefit heating and/or cooling processes. In some parts of the world, where there is volcanic activity (relatively near the surface), geo-thermal means boring deep down into the earth and pumping very hot water to drive power generation. This is not the same thing as geo-thermal in Florida. In similar parts of the country, geo-thermal can mean boring 1000 feet deep to pump out reasonably warm water to use in selected heating processes. This is not the same thing as geo-thermal in Florida. In many parts of the country, geo-thermal means burying large quantities of piping just below the surface of the earth or below the surface of a lake. Water is pumped through these pipes and used by heat pumps. This is not the same thing as geo-thermal in Florida. Geo-thermal is Florida is taking reasonably cool water in the state wide aquifer system and pumping it through heat pumps, which heat and cool buildings and pools. The water is returned back into the aquifer. It is easy to read or hear of geo-thermal being used successfully in one part of the world and assuming that is what people are ...
