" Filters outdoor particles before fresh air is delivered to the home " Look closely a what you can fit in as a filter for keeping dust and other stuff out of your house. And access to change the filter.

Definitely. The final plan will certainly involve an easy access to mechanical parts necessary for maintenance/repair. Fortunately (and unfortunately) my ceilings are exposed from asbestos abatement so should be easier to build out that access if necessary.

The hood "horizontal run should be angled slightly to "drain" toward the hood. Suggest a Fantech LD-10 silencer in the hood duct path between hood and blower. Ditto for MUA path between blower and outlet into house.

MUA control performance (balance) has to avoid under-pressurizing the house per the list below. I don't know what adjustments are available on the Fantech MUA system.

I expect you will be using 10-inch duct. These are fairly challenging to wrestle around, particularly with interfacing silencers and blowers. A helper will prove valuable, I think. Consider Fantech clamp type interface devices.

Residual vibration can be further suppressed with automotive panel dampening material; the silencers mainly manage higher frequency blade tip turbulence noise. Hang components from rafters rather than support on attic joists.

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Mechanical-Draft Appliances

Heating systems with fan-powered exhaust systems can withstand higher negative pressures than natural-draft appliances. Some types of fan-powered systems are much better than others, however. In order of effectiveness, the choices are:

« Sealed-combustion. Also called “direct vent,” these appliances draw all combustion and dilution air from outside. These can typically tolerate negative pressures in the range from 25 to 50 Pa.

* Power-vented. These draw their makeup air from indoors and are also called fan-assisted, forced-draft, or mechanical-draft. These can typically tolerate up to 15 to 20 Pa of negative pressure.

* Induced-draft. These have a small fan added for energy performance, not to overcome house depressurization. These can typically tolerate 5 to 15 Pa of negative pressure.

By comparison, an atmospherically vented furnace can back-draft with as little as 5 Pa of negative pressure, and a gas water heater will have spillage at 2 or 3 Pa. Fireplaces can start having problems at about 3 Pa. Canadian codes limit negative pressures in homes with atmospherically vented equipment to 5 Pa. U.S. codes do not currently address the issue (in a plainly spelled out "prescriptive" number).

1 pascal = 0.00402 inches, water column

1 atmosphere = 407 inches, w.c.

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If MUA components are mainly in the attic, dump into the kitchen via a ceiling diffuser aiming the air flow away from the hood. (Diffuser vs. register, see Hart & Cooley.)

MUA should take its air away from the hood exhaust, preferably upwind and higher. Gutted down-blast commercial blower housings can also be used on the roof, or something that is configured like the intake section of commercial MUA rooftop housings.

Review the relevant contents of this document:

https://www.tagengineering.ca/wp-content/uploads/2015/02/KVSApplDesign_catalog.pdf

KasekiI, thanks for your comments. I was secretly hoping you would chime in. I’ve read alot of your input on previous posts and its been very helpful.

“MUA should take its air away from the hood exhaust, preferably upwind and higher.“ Do you mean the intake shouldnt be close to the exhaust? If so, that shouldnt be a problem.

I havent looked so much into the external roof blowers. Maybe its better to have that than inline in the attic? One better than the other, or is it mostly a noise thing?

Also, while we are discussing dumping air. Esthetically the would be nice ( https://inviair.com/l245-p-2-slot-linear-diffuser-45-opening/ ) but ive heard bad things about the amount of CFM these can push. Ive got a 10 foot wall on the other side of the range… i could just run multiple diffusers along that 10 foot of ceiling, similar to the picture in the website to make it look more pleasing to the eye.