Here's a youtube. This is how I've cleaned my make up brushes as well as my paint brushes. You don't need the brush cleaner he speaks of for your make up brush, just the technique of rolling it around in the palm of your hand. It may take a while to get all the soap out, as make up brushes are considerably denser than paint brushes. at the time frame 1:41 where he's "bending" the bristles back & forth, this is really good for working the soap out. Good luck!

We've got all the intake and exhaust ducting done. Waiting on him to come back out so we can do all the wiring/testing/adjusting. The intake is shown above. This connects into the 14" return duct. I took out the Honeywell controller. On the "Off" position, it says "remote switch only". This is awesome and actually answers my question without having to look in the instructions. "On" can be used from Mar-June and from October to November-ish and will act as a Fresh Air system, given the balancing adjustments are made and such from the HVAC guy. "Off" can be used for the extreme months. Even in "Off" position, it will STILL open after we hook up a switch from the range hood to the damper. This is great news. Basically, "Off" is make-up air only, and "On" will be fresh air AND make-up air. The only thing that will deserve some extra credit is if we can wire it in a way for the Honeywell switch to ignore if it's on low speed. Not a big deal though. I thought of one awesome benefit that I didn't think about for make-up air. I have a small theater room that gets warmer than most rooms. We installed a jumper duct to the hallway where the main return is. That works great, as long as air handler is on. And it works "OK" at best. But with the fresh air system, this should help regulate the theater room temps in this situation which happens a lot: 6:00PM. Outside is 66-69F after the end of a pretty hot day. House T-stat is 71F. Theater room is 74-75F. Before the fresh air system, the only way to cool this room down would be to turn on the A/C. This increases the chance of freezing and is not really solving the problem. But I'm thinking now with the fresh air systems kicking on at usual intervals, blowing in 66-69F air from the outside should help reduce theater room temperatures and at least provide more air flow.

"Thank you, Kaseki! I’ve been reading your past posts-would you mind sharing again what cooking device/range hood/ makeup air system you chose and why?" You may find images of elements of my kitchen in various posts. I won't repeat them here. Also, some hood flow parameters may be found in FAQ I. Please note that my kitchen reno planning began in 2007, with most purchases of appliances made at the end of that year. Delivery was taken significantly later for most items, but well in time to confirm measurements and interface details. Explaining rationale would make this tediously long, take too much of my time, and jack this thread. I owe a kitchen photo to the FAQ II thread, and one or more should appear in the fullness of time. The cooktop: I have two induction cooktops, a 36-inch Frigidaire Gallery (replacing a 36-inch Electrolux clone Kenmore that failed after 5 years or so) and a Cooktek 3500W induction wok. These are set in soapstone over cabinets in which there is added stone support and wire racks for pans, providing maximum air volume for cooling. The hood system: Overspreading these is Wolf's largest Pro Island hood set at 34.5 inches above the counter. The hood connects to a damper, then a Fantech silencer, and then a Wolf (Broan) 1500 CFM roof blower (which has a damper). (As I have explained many times, once installed in a hood system blowers cannot flow their rated CFM due to pressure losses. I have measured, however, about 1000 CFM with presently passive MUA and no other household exhaust blowers operating.) Duct is 10-inch. The secondary hood system: There is a secondary system comprising a pair of ceiling registers (14 x 20 if I recall), 3M Filtrite filters in the register boxes, a damper, silencer, and roof mounted NuTone down-blast blower. I believe this blower is rated 600 CFM, but can't find my literature for it as it was originally bought to provide additional flow for a '70s cooking center with miniscule blower performance. The registers are ceiling mounted over a pair of Wolf wall ovens. The MUA: I have planned an active MUA system, but all parts have not yet been acquired. There seems to be no end to new "required" projects. The system as it presently exists is operated passive, and comprises a highly ventilated attic with an additional roof-mounted down-blast commercial blower housing for eventual ducted air intake, a one-inch pleat 24 x 24 furnace filter (to be replaced with a lower pressure loss 4-inch pleated canister version, a 30 x 30 heat exchanger connected to my oil-fired hydronic heating system, and a 36 x 36 diffuser at the end of a hall that connects to the kitchen. The control system for this is intended to keep the kitchen pressure equal to the outdoor pressure (which will be the attic pressure once the MUA is ducted). Some elements of this are place. A Fuji computer module in a DIN control array next to my furnace will attempt to adjust its natural frequencies (poles and zeros) such as to make a stable MUA system independent of the main hood flow rate, the wall oven vent flow rate, and bathroom blower flow rates. The differential pressure sensor upstream and motor downstream control loops are 20 mA current type. Separate sensors and controls are used to keep the heat exchanger from freezing when not in use and otherwise keeping the air passing it temperate. Blower will be the largest that can get into the attic that Fantech sells that incorporates the 10 Vdc control voltage motor. (I forget the part number.) This wasn't available back ca. 2010, nor did Fantech list a motor controller that could handle that size motor back then. If starting from scratch, I would investigate the present offerings of Electro and Fantech to minimize my work, but large flow rate in an assembled unit would likely not fit into the attic without removing the diffuser and heat exchanger for a one-time installation. While balanced air pressure is highly desirable for several reasons repeated often on this forum, I should note that my System 2000 oil furnace has its own MUA and a sealed exhaust stack installed within the original brick chimney that served the previous one- and two-generations-back Beckett boilers. The hot water storage is heated via a hydronic loop on the furnace, and the dryer is electric. Hence, back-drafting of combustion appliances is not an issue. To deal with the flow to the MUA heat exchanger (capable of 120k BTUh if necessary) as well as the longer reaches of my house hydronic plumbing, I use a larger (higher head vs. flow rate) Taco pump than is usual.

Many answers related to this may be found on the Appliances forum where hood system issues are routinely discussed. There are code requirements for MUA, and a safety requirement. The safety requirement drives the code requirements, in a somewhat crude manner in most cases. The safety requirement is to not back-draft combustion appliances. This is moot if the appliances have their own make-up air and have sealed exhausts, or are in a space sealed from the kitchen or otherwise isolated. Code might apply anyway. The image below provides examples of the differential pressure between inside and outside that can cause back-drafting. Inches of water mean inches of water column, where atmospheric pressure can pull a water column about 407 inches high against gravity. Click to enlarge. A passive (no blower, large duct) solution should still have filtering, and in most cases heating. The filtering alone will cause some pressure loss. See table in the image below. Feet per minute (fpm) are per square foot of filter and thus equal CFM per square foot. So passive MUA is a potential solution where back-drafting risk is negligible. A duct diameter equal to that of the hood duct would probably pass code. In this case, it is better to ask (the AHJ) for permission rather than forgiveness. Where the pressure loss in the MUA path is too high, then an active (with blower) MUA system is needed. These can be controlled by various schemes to balance indoor pressure relative to outdoor pressure. It is worth noting that the actual flow rate of the hood system is likely only 2/3 of the blower's rated flow due to pressure loss in the hood system, particularly in the hood filter (mesh or baffles) vs. the blower's "fan curve." In order that the MUA not cause turbulence at the cooking zone that can cause failure of the hood intent -- capture and containment -- MUA needs to be introduced "quietly." That is, MUA flow should be expanded into a diffuser much larger than its duct size. If introduced near the hood, the MUA flow should be directed away from the hood (across the ceiling), and if introduced at the floor aimed so that doesn't interact with the cook moving about. Commercial kitchens can sometimes get away with dumping the MUA under the cooking zones, all of which are raised above the floor, but otherwise typically introduce the flow at the ceiling. Test kitchens use perforated walls without intervening equipment. Passive MUA is generally self auto balancing, but the balance is not too good as may be seen from the filter table above. Assume for convenience a 2' x 2' x 4" cassette pleated filter. For example, a MERV14 4-inch filter at 1200 CFM (300 fpm per square foot) would have a pressure loss of 0.29 inches, or 73 Pa, requiring a blower unless there were no combustion appliances. (Estimating 0.2 inches, w.c., at the 800 CFM a 1200-CFM rated hood blower would likely deliver against the hood pressure loss, or 200 fpm at the MUA filter, we are still at 50 Pa, and combustion appliances, if present, really need to be in their own room with its own MUA to get away with passive MUA. Active MUA where the only significant flow is via the kitchen hood can use hood system blower motor current sensing, duct flow sensing, or actual pressure sensing if the hood blower uses variable speed control. With multiple household exhaust blowers and with fireplaces (not sealed having their own MUA, and intended for use during cooking), pressure sensing based motor control may be the only practical scheme. For contrast, large buildings are kept pressurized to aid door opening against winds, passive bathroom exhaust flow, etc. They run constant rpm blowers that feed ducting that includes a bypass duct to the blower intake. This bypass is controlled by building internal pressure vs. external pressure. Passive pneumatic damper control is feasible for this.