Posts Tagged ‘HVAC engineering’
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 ...
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, ...
How Long Will Your Building Last?
-How much money should you have saved up for building repairs? -How much life is left in your building under current trends? -Can your building’s life be extended? -Can you upgrade to a Sustainable Green building when it comes time to replace materials and equipment? -Is deferred maintenance going to disrupt your organization’s financial plans? Offering you an un-biased professional report on your building’s future. Contact Us for details.
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 ...
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 ...
energy independence is America’s future.
Happy 4th of July!Celebrate Your Personal Energy Independence Energy Star sent out promotion on personal and residential energy independence. Commercially, there are almost always unused opportunities waiting to be tapped. With 4th of July celebrations upon us—as well as the summer heat—no one wants their energy bills to rise with the temperature. Now is the time to think about how to manage your home energy use effectively, practically, AND economically. So, to coincide with our nation celebrating its independence, the U.S. Environmental Protection Agency's (EPA) ENERGY STAR® program is bringing you cooling tips for every budget, as well as some tips for travel if you're getting away—small steps that can help make a big difference in saving energy, money, and fighting climate change. Cooling Tips for Every Budget Summer Travel Tips Take the ENERGY STAR Pledge Cooling Tips for Every Budget Staying cool this summer doesn't have to mean cranking up the AC and spending a lot of money. A typical household spends almost 20 percent of its utility bill on cooling. EPA's ENERGY STAR program has some low-to-no cost energy-saving tips to beat the heat and save money, too. No-Cost Program your thermostat to work around your family's summer schedule—set it a few degrees higher when no one ...
salt air problems
Salty ocean air can drift a mile or more inland. Since Florida has so many miles of coastline, this presents a common problem in air conditioning equipment. Regular untreated fins on air cooled air conditioning equipment have a hard time with salt. It corrodes the aluminum in the outdoor condensor coils. Outdoor air cooled equipment winds up wearing out in half it's expected life. While all coil coatings boast perfection, few deliver it. Expertly applied brand name coatings can cost almost as much as the equipment by the time all is said and done. Geothermal has an advantage here. There are no outdoor aluminum fins. Instead, a smaller and more durable stainless steel plate and frame heat exchanger resides outside in it's place. The heat exchanger can be insulated or easily housed to provide additional salt protection. Naturally, heat exchangers and pumps are quieter than air cooled condensing units or air cooled chillers.
geothermal hybrid systems in florida
While geothermal has distinct advantages over cooling towers (no makeup water, less scaling in chiller and tower, better efficiency during hot months), there is one time in Florida where cooling towers outperform geothermal. During cooler weather, cooling towers can produce water below 74F, which adds even more energy savings. For cooling plants considering replacement of it's cooling towers, it is worth a study to determine the feasibility of refurbishing the best tower to serve the chiller which normally handles the winter cooling loads. The remaining chillers can operate from geothermal. For cooling plants that operate extended hours (like 24/7 for example), this could be even more attractive to a straight geothermally cooled chiller plant. Guy Van Meulebrouck PEconsulting engineerguy@guyvanmconsulting.com10947 US 98 NorthLakeland, Florida 33809-1087 Want permission to reprint this article? Please email with your: name, title, company, the publication you are reprinting, the parts of the article you are reprinting, and your contact info.
