DC1700 Battery Operated Air Quality Monitor with Accessories - Portable Indoor Air Quality Tester for Home, Office & Travel

8/16/17 - Update - The fan noise finally got me to locate a quieter fan solution. Noctua just released a 5v 60mm fan that bolts in. It was only available from Amazon UK (https://www.amazon.co.uk/gp/product/B01G20CHX4/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1). I ordered a couple to test with. Big improvement. 10db quieter with the same airflow. See the attached photos. These are A/B photos showing one unit with standard fan and the second with the Noctua - db at about an inch from the fan and fan speed taken at about 1/2" from the vent. The fan swap takes less than five minutes. Remove four case screws, cut fan wires, strip fan wires, remove stock fan, install Noctua fan with two wire conversion clip (included), use included crimps to join wires, reassemble. Worth the trouble if you keep the unit in a main living area. You can still hear it, but it's no longer obtrusive.Next project is building a cosmetically improved case and integrating additional air quality sensors and a serial to wifi solution to put the device on the network without being connected to a PC. I'll update again once I have that figured out....8/6/17 - UPDATED - After a bunch of bench testing and some back and forth with Dylos, I've come to the conclusion that the issues I'm seeing are related to the power connector rather than the battery or power supply. Bizarrely, after about 30 plug/unplug events during bench testing, the connector started working reliably again. I'm raising my rating back up to 5 stars. This really is the best air quality meter available for the money. If you run into intermittent power issues, test the connector. I would highly recommend saving the money and not buying the battery version though.7/10/17 - UPDATED - So, today, after 5 months of use, the unit reports Low battery and refuses to stay powered on when connected to power. So I go to the manufacturers website to see how to get this fixed. Stupidly I did not confirm what the warranty was prior to purchase - It's 90 days. So, not I understand why it's 90 days.... This tool works well for its intended purpose, but at almost $500 a 5 month life span with only 90 days of warranty is completely unacceptable. If you are looking at buying one of these, DO NOT BUY THE BATTERY VERSION OF THIS PRODUCT. You are paying for a feature that insures the device lasts less than 6 months and is then useless. The fact that a dead battery kills the device is ridiculous. I've emailed the manufacturer to determine what can be done, but honestly, I'm not optimistic.I will update again if I get anywhere with repairing this device.ORIGINAL 5 STAR REVIEW BELOWThis devices is worth the money. I bought it to test the air quality in my house and to try and figure out what was triggering my breathing problems in my house. It is pretty amazing how effective this device is for this purpose. My house, with only the HVAC running reads from about 10-180 which is excellent air quality. If I run the gas fire place without running the HVAC is jumps to 1700-2000, horrible air quality. The fireplace is a direct vent high efficiency model. When we cook, depending on what is being cooked, the room the device is in will jump to a minimum of 1400 and I registered as high as 4000 when something was burned. This is with the range ventilator on. If we don't run the HVAC fan to filer the air (Merv 16 filter), the air quality will remain horrible for 8-10 hours. If we run the HVAC while these polluting situations are occurring, the room is back to <300 within an hour.What this has shown me is that the house has insufficient make-up air for the range hood, and it likely has a pressure balance problem when running the fire place. Very enlightening. Until I can get a make-up air system and an ERV installed, I'll be running the HVAC fans on circulate throughout the day.One star is deducted because the device looks "cheap" due to the molded plastic and huge gaudy white logo and, more importantly, it is really loud due to the small fan. If your room is quiet, and this thing is running, it is distractingly loud. For the price, these two areas are disappointing.In case the manufacturer reads this review, here are a few suggestions for improving the device:1. - Change the form factor of the device make the device large enough to house a 120mm Zalman silent fan.2. - Build the case out of metal for durability and improved cosmetics.3. - Include support for wall mounting and POE power and connection to a network for remote data logging, and even better, an API so it could be tied into an automation system - think Crestron on the high end or Vera on the low end seeing the air quality dropping below a configured threshold and automatically ramping up the fan speed of the ERV and HVAC fans to filter the air faster and then automatically lowering the speeds once the condition is corrected.4. - Give an option for remote sensors - imagine wireless sensors that could be installed different rooms feeding back to a master device.