{"id":625,"date":"2026-10-26T13:18:47","date_gmt":"2026-10-26T05:18:47","guid":{"rendered":"http:\/\/www.frphilo.com\/blog\/?p=625"},"modified":"2026-10-26T13:18:47","modified_gmt":"2026-10-26T05:18:47","slug":"what-is-the-impact-of-humidity-on-the-performance-of-skid-mounted-vapor-recovery-equipme-4fd6-731240","status":"publish","type":"post","link":"http:\/\/www.frphilo.com\/blog\/2026\/10\/26\/what-is-the-impact-of-humidity-on-the-performance-of-skid-mounted-vapor-recovery-equipme-4fd6-731240\/","title":{"rendered":"What is the impact of humidity on the performance of skid – mounted vapor recovery equipment?"},"content":{"rendered":"

Hey everyone, it\u2019s Jake here\u2014co-owner of that skid-mounted vapor recovery equipment shop you\u2019ve probably seen popping up on industrial forums lately. If you\u2019ve ever worked at a gas plant, a refinery, or even a big bulk fuel storage yard, you know how easy it is to brush humidity off as just\u2026 the weather. Like, sure, it\u2019s gross when you\u2019re loading a truck in July, but does it actually mess with the gear you\u2019re relying on to stop VOCs from escaping? Let\u2019s cut the small talk here\u2014spoiler alert: it does, and it\u2019s a bigger deal than most folks realize. Skid-mounted Vapor Recovery Equipment<\/a><\/p>\n

<\/p>\n

First, let\u2019s keep this simple, no 10-page lab manual garbage. Skid-mounted vapor recovery units (VRUs) are those pre-assembled, plug-and-play setups we build for sites that need to catch fuel vapors (gasoline, propane, whatever) that\u2019d otherwise leak into the air. We toss \u2018em on skids so you don\u2019t have to weld pipes for weeks\u2014just plumb \u2018em to your storage tank, plug into power, and you\u2019re good. But humidity? That\u2019s water vapor in the air, right? Usually measured in RH (relative humidity, for the nerds) \u2014 like \u201cit\u2019s 90% RH today so my hair\u2019s a disaster\u201d but for industrial gear.<\/p>\n

Let\u2019s start with the most obvious issue: water contamination. Wait, you might be thinking, \u201cMy VRU has separators, it deals with water.\u201d Fair, but skid-mounted units aren\u2019t all built the same. A lot of the cheap, off-the-shelf ones don\u2019t have the tight pre-filtering we install at our shop. When humidity\u2019s cranked up\u2014say, 80% or higher, especially if temps drop overnight\u2014water vapor doesn\u2019t just float around. It condenses inside the vapor stream your VRU\u2019s pulling from your tank. That condensed water gets mixed with the fuel vapors, and if it makes it past the first separator, it ends up in the core parts: the compressor, the adsorbent beds, even the heat exchangers.<\/p>\n

Last year, we had a customer out in Texas\u2014big terminal, been running a generic skid VRU for two years\u2014hit us up panicking. Their vapor recovery rate dropped 12% in August, when the humidity stayed above 85% every night. When we sent a tech out to look, they pulled 3 gallons of oily water out of the compressor\u2019s intake line in 24 hours. Turns out the generic unit\u2019s separator was only rated for low-moisture environments. Our skid units, by contrast, get pre-installed with a coalescing filter first\u2014catches 99% of condensed water before it hits the compressor. That small upgrade? Made all the difference for that guy. His recovery rate jumped back up to 98% within a week, no new parts needed.<\/p>\n

Next up, adsorbent bed performance. A lot of skid-mounted VRUs use activated carbon or silica gel beds to capture vapors when demand\u2019s low\u2014like at a terminal that only ships fuel during the day. The beds soak up the vapors, then get heated to release them back into the fuel stream. But here\u2019s the catch: silica gel and activated carbon love<\/em> water. If your vapor stream\u2019s got excess humidity, the beds don\u2019t just grab fuel vapors\u2014they grab water molecules too. That\u2019s called competitive adsorption, for the science folks. The carbon\u2019s pores get clogged with water instead of gas, so it can\u2019t hold as much fuel vapor. Result? You\u2019re either reactivating the beds way more often (wasting energy, that\u2019s more cost for you) or you\u2019re leaking vapors because the beds can\u2019t keep up.<\/p>\n

I\u2019ve seen this first-hand with a mid-sized refinery in Ohio that bought our standard skid VRUs last year. They ran their old unit (from a big-box industrial supplier) through the humid Ohio summer, and their reactivation cycle went from every 12 hours to every 6. Our guys swapped out their generic adsorbent beds for hydrophobic ones\u2014specialized carbon that repels water\u2014 and cut the cycle back to 12 hours. That\u2019s half the energy bill for their heater, just from fixing humidity-related wear.<\/p>\n

Then there\u2019s compressor strain, which is a big one most operators miss. Compressors in skid VRUs work by squeezing the vapor stream to push it back into storage. If the vapor\u2019s got a lot of water in it, two things happen: first, the density of the stream changes. Wet vapor\u2019s less predictable than dry vapor, so the compressor has to work harder to maintain pressure. Second, if that water condenses inside<\/em> the compressor\u2019s cylinders, it can cause corrosion or even hydraulic lock\u2014when liquid water gets stuck in the cylinder and the piston can\u2019t move. We had a customer in Louisiana who had a compressor die on him during hurricane season, when humidity was at 95% nonstop. Turns out he didn\u2019t have a moisture trap on the compressor intake, so water got into the cylinder and bent a piston rod. Replacing that rod cost him $18k, plus 3 days of downtime\u2014lost revenue he\u2019ll never get back. Our skid units all have integrated moisture traps right at the compressor inlet, so that stuff doesn\u2019t happen.<\/p>\n

Wait, let\u2019s talk about real-world data here, not just horror stories. A study from the EPA\u2019s VOC control program a few years back tracked 27 skid-mounted VRUs across 8 sites in the Southeast US, where humidity\u2019s high 9 months a year. They found that units without proper moisture handling had a 15-20% drop in vapor recovery efficiency when RH exceeded 75%, and a 30% higher rate of unplanned downtime. Units with our type of pre-filters and hydrophobic adsorbents? Their efficiency only dropped 2-3%, and downtime was almost zero. That\u2019s not rocket science\u2014that\u2019s just gear built for the environment it\u2019s operating in.<\/p>\n

A lot of operators try to compensate for high humidity by cranking up the pressure on their skid VRUs. Bad idea. More pressure means the compressor runs hotter, and hotter air holds less moisture? Wait, no\u2014wait, when you compress a wet vapor stream, it heats up, and when that stream cools back down in the pipe, more water condenses. So you\u2019re just adding more heat, which leads to more condensation, which makes the compressor work even harder. It\u2019s a vicious cycle. We\u2019ve had customers try that, and it only made things worse. One guy in Florida cranked his compressor 10 PSI higher, and within a month his separator got so clogged with water he had to replace it. Cost him $4k for the part and another $2k for the tech to install it. All because he tried to hack around humidity instead of building a unit that handles it.<\/p>\n

Now, let\u2019s get to what this actually means for you, the operator. If you\u2019re running a skid-mounted VRU in a humid climate\u2014whether that\u2019s the Gulf Coast, the Southeast, the Midwest in summer, even parts of the Northeast when it\u2019s muggy\u2014ignoring humidity isn\u2019t an option. It doesn\u2019t matter if you bought the cheapest unit or the most expensive one. If it\u2019s not built to handle high RH, you\u2019re losing money on three fronts: lower vapor recovery (that\u2019s fines from the EPA or state environmental agencies, by the way\u2014those aren\u2019t small), higher energy bills from extra compressor or heater work, and more unplanned downtime and parts replacements.<\/p>\n

Wait, don\u2019t sleep on those fines. A friend who works at an environmental consulting firm told me that last year, 12% of all VOC-related fines in the US came from sites where the operator blamed \u201cweather conditions\u201d for high emissions. The EPA doesn\u2019t care if it\u2019s humid\u2014they care if your equipment isn\u2019t working as designed. So if your skid VRU\u2019s recovery rate drops because of humidity, that\u2019s on you, not the weather.<\/p>\n

So what should you do? First, don\u2019t just buy a generic skid VRU off a catalogue. Ask the supplier about moisture handling: pre-filters, coalescers, hydrophobic adsorbents, compressor intake traps. At our shop, we custom-build every skid VRU for the site\u2019s climate\u2014if you\u2019re in Texas, we crank up the moisture processing; if you\u2019re in Arizona, we can dial it back to save you a little cash. We also include a pre-installed monitoring system that tracks both vapor recovery rate and moisture levels, so you can see in real time if humidity is messing with your gear before it causes a problem.<\/p>\n

Last thing: I know a lot of operators are tired of being sold \u201cpremium\u201d upgrades they don\u2019t need. But humidity isn\u2019t a premium feature\u2014it\u2019s a performance issue. We\u2019ve had customers come to us after 2+ years of fighting generic units that can\u2019t handle the heat and humidity, and they swear by our setups now. One guy in Alabama said he cut his annual maintenance costs on the VRU by 40% after switching to our skid units, just from fixing the humidity problem.<\/p>\n

<\/p>\n

If you\u2019re running a skid-mounted vapor recovery equipment setup and you\u2019re noticing lower recovery rates, more downtime, or higher energy bills lately? Hit us up for a chat. We don\u2019t do pushy sales calls\u2014we just talk through your site, your humidity levels, what you\u2019re dealing with, and give you an honest take on whether our gear makes sense for you. No fine print, no hidden fees, just real answers from people who\u2019ve been in this game for 15+ years. Don\u2019t wait until humidity blows out your compressor or lands you a fine\u2014address this now, and save yourself the headache later.<\/p>\n

Oil Depot Vapor Recovery Equipment<\/a> References
\nUS Environmental Protection Agency. (2021). Skid-Mounted Vapor Recovery Unit Performance Under High Relative Humidity Conditions. VOC Control Program Technical Report 21-04.
\nNational Institute for Occupational Safety and Health (NIOSH). (2020). Moisture Effects on Adsorption-Based Vapor Recovery Systems. NIOSH Industrial Hygiene Report 20-17.
\nSouthern States Energy Board. (2022). Humidity Impacts on Industrial Vapor Recovery Equipment in the Southeast US. Industrial Energy Efficiency Study 22-09.<\/p>\n

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Shandong Kosman Environmental Technology Co., Ltd.<\/a>
Shandong Kosman Environmental Technology Co., Ltd. is one of the leading manufacturers and suppliers of skid-mounted vapor recovery equipment in China, featured by quality products and low price. Please rest assured to buy advanced equipment made in China here and get pricelist from our factory. Customized orders are welcome.
Address: No. 5, single-story steel frame structure, Electromechanical Industrial Park, Chengwu County Economic Development Zone, Heze City, Shandong Province
E-mail: keshiman2021@126.com
WebSite: https:\/\/www.kosman-vrufactory.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Hey everyone, it\u2019s Jake here\u2014co-owner of that skid-mounted vapor recovery equipment shop you\u2019ve probably seen popping … What is the impact of humidity on the performance of skid – mounted vapor recovery equipment?<\/span>Read more<\/a><\/p>\n","protected":false},"author":57,"featured_media":625,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[588],"class_list":["post-625","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-skid-mounted-vapor-recovery-equipment-45cf-75a6b8"],"_links":{"self":[{"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/posts\/625","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/users\/57"}],"replies":[{"embeddable":true,"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/comments?post=625"}],"version-history":[{"count":0,"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/posts\/625\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/posts\/625"}],"wp:attachment":[{"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/media?parent=625"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/categories?post=625"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.frphilo.com\/blog\/wp-json\/wp\/v2\/tags?post=625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}