Pre-conference workshop led by William P. Lull<\/p>\n
31 May 2011<\/p>\n
Notes by\u00a0participant Priscilla Anderson\u00a0<\/p>\n
In a solid day of information-packed lectures, Bill Lull explained the basic elements of the systems that control air temperature, humidity, and quality in typical collections storage buildings, and then talked about many ways that we can decrease energy use by those systems.\u00a0\u00a0 He framed the day by asking the following questions:\u00a0 What is the system?\u00a0 How does it work?\u00a0 What can we do to make it work more efficiently?<\/p>\n
Key takeaways<\/strong><\/p>\n Systems are usually overbuilt so they have the capacity to accommodate the peak demand (the hottest, coldest, driest, and most humid days of the year).\u00a0 However, they use a lot of energy at the peak.\u00a0 But they are much more efficient when running at partial power.\u00a0 So if you have variable speed fans, you can turn them down on days that don\u2019t have extreme heat or cold coming in from the outside.\u00a0 \u00a0They will use less energy than a smaller sized fan running at top speed.\u00a0 Bill gave the analogy of a Prius going at top speed versus a BMW just keeping up with the Prius\u2026the BMW has much better gas mileage at the Prius\u2019 top speed!\u00a0 Optimize your overbuilt systems, tweaking them to accommodate different weather patterns<\/p>\n Bill made a plug for the work that IPI has done (providing PEMs and software that\u2019s easy to use so we have data to use when talking with Operations), and for promoting the idea that we can improve energy efficiency by using existing equipment, maybe doing some component upgrades, tweaking setpoints, make the existing \u00a0system work better.<\/p>\n Optimizing existing systems to improve energy efficiency<\/strong><\/p>\n Cooling systems:\u00a0 Some cars have a gauge in the car that tell you the real-time miles per gallon so you can see the impact of how you drive.\u00a0 Most HVAC systems don\u2019t have energy meters installed on individual equipment, so it\u2019s hard to know how to optimize the system.\u00a0 Siemens will install one of these meters for approx. $16,000 for two chillers.\u00a0 Having feedback about the energy use at the device helps you make intelligent choices about how you operate that device.\u00a0<\/p>\n Other things you can do with your chiller:<\/p>\n If you don\u2019t have a dehumidifier, but you have high humidity, then use your chiller to cool the air to the dew point in order to condense liquid water out of the air.\u00a0 52 degrees F is cool enough to get air that will then be 50% RH at 70 degrees F.\u00a0 So you can use your chiller as a dehumidifier.\u00a0 Then you have to heat the air back up to the desired temperature again, so that takes some energy.\u00a0 But since cooling systems have heat as a byproduct, you could conceivably recover that \u201clow-grade heat\u201d and reuse it.<\/p>\n Fans: Install variable frequency drives on fans so you can operate them at reduced capacity.\u00a0 Fans operated at 50% speed only use 15% of the energy.\u00a0 There is a double bonus for slowing down your fans that is predicted by a mathematical equation I won\u2019t reproduce here.\u00a0 Basically, when you have less air flow, that gets multiplied by a pressure number that is non-linearly lower\u2026you get the pressure drops further along in the system (filters, etc) that then results in much less energy use.<\/p>\n Pumps: \u00a0If you reduce the gallons per minute, you can get a similar double effect for energy savings as the fan system.<\/p>\n Air quality: we don\u2019t need as much fresh air (oxygen) as we think.\u00a0 In fact, we can re-breathe our own air as long as we get rid of the carbon dioxide that we offgas. \u00a0Dilution with outside air is the least efficient\u00a0 method of getting rid of CO2. \u00a0So if you can filter out CO2, then you can have a lot more re-use of air rather than bringing in outside air that then needs to be conditioned. \u00a0\u00a0<\/p>\n Lighting is a significant source of heat in a building, so in the summer you have extra load that you have to cool building because of lighting.\u00a0 You\u2019re using energy to turn the light on, and then more energy to cool off the air that was heated up by the light.\u00a0 So turn off the lights in the cooling season!<\/p>\n Things not to do:<\/strong><\/p>\n Night-time shut downs you are shutting it down at the time when it would be operating more efficiently anyway (not as much cooling needed at night), and then you need to do more to catch up during the peak load time (hot day).\u00a0<\/p>\n Cyclic control: on\/off\/on\/off uses 50% of the energy.\u00a0 Variable frequency drive only uses 35% of the energy to meet the same load.<\/p>\n Filters: Do not get rid of filters!\u00a0 But you can use extended surface area filters.\u00a0 Slow down the fan instead to save energy.\u00a0<\/p>\n New construction\/building design considerations:<\/strong><\/p>\n You don\u2019t want operable windows in an all-air system\u2026too much imbalance on the system, and the air that comes in doesn\u2019t get mixed well in the spaces.\u00a0 Opaque, insulated walls have the smallest loads (i.e. they leak less than fixed windows, and much less than openable windows and doors).\u00a0 Daylighting (windows, skylights) does not save energy\u2026what you save in lighting, you pay more for in load (cooling in the summer).\u00a0<\/p>\n Don\u2019t use pressure sensors\/pressurized systems\u2026there are better ways to manage outside air.\u00a0 In practice, they just don\u2019t work.\u00a0<\/p>\n It\u2019s important to advocate for separate air handler for storage and office spaces, since the air quality\/filtration (as well as temperature\/humidity) needs are so different.<\/p>\n Dehumidification: Pre-treat outside air with its own cooling coil to get some moisture out, so you don\u2019 t need a reheat.<\/p>\n Utilities<\/strong><\/p>\n Vocabulary check: \u201cgeothermal\u201d means dig a hole and steam comes out (volcanic activity nearby\u2026Iceland, Hawaii).\u00a0 For the kind of digging we do in North America, it\u2019s called Ground Source Heat Pump, where you send air\/water down a deep hole to condition it to a constant temperature (approx. 50 degrees F).<\/p>\n Photovoltaic (solar power) is very cost-effective.\u00a0 Many telephone poles have a photovoltaic array panels.\u00a0 They don\u2019t need much maintenance (unlike generators); that\u2019s why solar power is a sustainable source of energy.\u00a0 Solar panels can be for either hot water or electricity.\u00a0<\/p>\n Hydrogen powered cars are the future\u2026split water into O2 and hydrogen, then release the O2 and store the hydrogen for power.\u00a0<\/p>\n Hydro power is also a good sustainable source, because can ramp it down and up very quickly\u2026anything with steam doesn\u2019t have that flexibility.\u00a0 You can pump water up into a tower, and generate electricity by letting it run down whenever you want it.<\/p>\n Utility companies charge large institutions \u201cDemand Costs\u201d that are calculated by the peak amount used in a 15 or 30 minute period, then you\u2019re billed for that for the rest of the year.\u00a0 \u00a0So if you can reduce that peak amount by even just a little bit, then your costs will be lower over the whole year regardless of how much energy you use at other times.<\/p>\n","protected":false},"excerpt":{"rendered":" Pre-conference workshop led by William P. Lull 31 May 2011 Notes by\u00a0participant Priscilla Anderson\u00a0 In a solid day of information-packed lectures, Bill Lull explained the basic elements of the systems that control air temperature, humidity, and quality in typical collections storage buildings, and then talked about many ways that we can decrease energy use by … Continue reading “Saving Energy in HVAC for Conservation Environments”<\/span><\/a><\/p>\n","protected":false},"author":99,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,20],"tags":[],"class_list":["post-1328","post","type-post","status-publish","format-standard","hentry","category-annual-meeting","category-reception"],"_links":{"self":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/posts\/1328","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/users\/99"}],"replies":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/comments?post=1328"}],"version-history":[{"count":0,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/posts\/1328\/revisions"}],"wp:attachment":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/media?parent=1328"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/categories?post=1328"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/tags?post=1328"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}