For the uneducated (like me who is just starting down this road with a 60" Capital Culinarian with gill and griddle) perhaps you should name names.....I would like to know what to avoid out of the gate rather than buy, try, buy and try again and again. I am looking at a custom Modern Aire and Raw Urth. I dont want to make a mistake.

Thanks!

If memory serves (an inconsistent servant, I'm afraid), Clinresga reported on two different fan systems that were in his two properties. If one uses google search with this forum's base URL and Clinresga and hood and noise as search terms, you may find relevant threads, such as the one listed below.

Here is a link that might be useful: Clinresga's measurements

I spent way too much time reading the posts and forums, and did not think I had room for external blowers. Ultimately I couldn't handle having a lovely kitchen that would have this huge noise generator going full tilt when I was cooking Thanksgiving dinner with my family.

So we gutted the hood, rewired the switch to control the external blowers. We bought a pair of fantech 8" inline blowers. We Ran new ducting through the ceiling to the outside of the house and found a creative way to hide the blowers in an overhang.

Without a doubt it was a pain in the ass and cost a lot more than budgeted, but in the end, I couldn't deal with a great kitchen that I couldn't use to entertain.

Had I known, I would have planned external blowers from the start.

If you'd like the name of the brand to avoid, email me and I'll reply privately.

from my point of view, it costs very little to buy galvanized duct.
any big box store has duct and transition pieces, at about ten dollars a pop.

from my point of view, it costs very little to buy a fan / blower / motor.
a fantech distributor might sell one to you for a couple hundred dollars.

the cost of installing the duct and motor is very little, from my point of view.
a handyman helper for a day is not a big expense.

the switch can be a wall switch. Fantech sells them too.

the "hood" , the visible capture canopy in the kitchen, can cost whatever you want it to cost.
any shape like a bell or an umbrella.

It's not a big deal or cost to get a filter to catch the major grease specks floating in the air.

This is my recipe. Separable items. The blower as a separate thingie, not in the "hood" and therefore not close to your ears. It puts the motor noise at some other place farther away than where it is when you buy a "hood+blower fan" all in one product that ships in one box and that remains attached.

When the blower is "inline" it is in the soffit or attic, in the duct line. This costs less than putting it on the outside wall.

1700 CFM is the entire air contents of a 12'x14' room with a 10' ceiling being exhausted EVERY MINUTE. A hurricane will move a little more air, but only a little.

Some common sense would suggest there's no way to move that much air quietly unless the ducts were very, very large and the fan is very remote.

How do you replace all that air, especially in the winter?

We had lots of these conversations (often turned into arguments...)

Ultimately the real cfm less due to the pipe length, elbows, filters, etc. Our kitchen area opens on both sides so we draw from a much bigger area. We replaced the speed control that came with the hood with a high quality variable speed control.

I can tell you that we regularly use it at full blast, particularly when we are wokking or cooking multiple dishes. Mostly we use it on low. Better to have needed capacity than smell hamburger in the upstairs bedroom all night.

We also designed in makeup air controlled by electronic damper. Took a little electrical engineering with relays, but it also doubles as an upduct for the swamp cooler in the summer.

As I recall we ran 2 8" pipes, and wish we had space to run 10". Fan is25 feet away from the blower, and there is a 'muffler' in between. We tested without muffler and tested with muffler, and found the muffler noticeably decreased the noise (I won money on that from my skeptical contractor).

The oven throws off a ton of heat, given that it is gas and the vent is at the back of the stove. There is some trade off with cold air entering the house, but since it comes into the kitchen directly, and the oven is throwing off heat, we don't find the air exchange to be a chilling problem. It might be different in colder climates.

1700 cfm is about a kilogram of air per second, although the likely actual flow will be less if 1700 is the blower's specified flow at zero static pressure. Given the specific heat of air around 1 kJ/kg-K, and, say, a 20 degrees kelvin required temperature rise, the power needed to condition the MUA is 20 kW or about 68,000 btu/hr. Taking 20 kW from the mains requires some planning, but is not beyond the capability of normal residential services. Alternatively, 68,000 btu/hr should not strain oil burning hydronic heating furnaces found is many homes.

kas

"....we ran 2 8" pipes, and wish we had space to run 10"....."
Galvanized duct can be made to any shape. A rectangular duct would have fit your space and provided a better result than two separate 8" round ducts outfitted with two 8" blowers. A rectangular duct could have been 8" on the short side, and whatever length on the long side that would fit the space available. Transitional duct pieces are easy to specify, easy to order custom-made over the phone or over the internet, and easy to ship. If there is a single pinch point that brings the sizing down to a smaller size, it is not a big deal (search Venturi effect for more learning about this). This is f.y.i. and good to know for your next house, or for the next reader. A single more powerful blower would go in the one duct line. Hth.