There's nothing magic about putting a brand X hood over a brand Y cooktop. In essence, you're asking people to research what a Savona hood is - how many CFM, what dimensions - and then research a Thermador rangetop - how many BTU's/hr - and then give you their opinions. You're far more likely to get answers if ask if a hood of a certain specification (CFM, dimensions) over a cooktop with a certain specification (number of burners, BTU's per burner) will work. You've presumably already done that research, why not include the information in your question? Finally, realize that this has already been asked many times before. Try using the search function and see if the information you want is already here.

Hi Melanie - Update: I received a push button assembly and a capacitor parts from Zephyr. We consulted our electrician (who happened to be on site doing unrelated work), he told us that our existing push button assembly is working fine so that part was not needed. He did install the new capacitor and said that by the sound the unit was making he could tell that electricity is feeding the unit adequately so that's not the issue either. He carefully lifted one of the two grids on the side of the blower and noticed that the blower wheel (sorry for not knowing the proper technical terms) was stuck in place, kind of gummed up, which is probably due to some grease accumulation over the years. He manually prodded the wheel to make it spin freely. He did this to both sides of the blower and the unit started working again. However, we still have the unpleasant screeching noises but have regained use of the hood. We decided to use it sparingly as long as it extracts odors, steam etc until we can replace it (or find someone who restores these types of motors.....not sure how cost effective that route would be though....). Thank you for your question and I hope you find a satisfactory solution!

I have the Zephyr Typhoon...used the 4 watt Lighting Ever LED's but they stand about 3/16" proud of the hood surface. As long as you replace both bulbs, it's not really all that noticeable or disagreeable. The LED's are so much better than replacing halogens every 30 days (or so it seems). As far as grease escaping thru the opening...that's a non-issue, really. The original halogen bulbs certainly don't form a vapor proof seal so it wouldn't make sense to expect replacement bulbs to block vapors either. To date, there doesn't appear to be a standard size for replacement GU10 LED's. Your best bet is to measure the original halogens and try to find an LED that is the same height AND puts out an acceptable amount of light. I was very pleased with the light amount/ quality of the Lighting Ever LED's & was aware of the variations in the height of the different brands of bulbs so decided to accept a less than perfectly flush fit.

There are a few sources of noise in a hood ventilation system (and potentially also in a powered make-up air system). The dominant noise when a silencer isn't or can't be used is fan blade tip turbulence noise. Second will be either baffle turbulence noise (more like a hiss), or its counterpart if mesh filtering is used, or duct turbulence noise. Baffle noise domination assumes that the duct is damped on the outside and the air velocity in the duct is not too high. Otherwise duct turbulence noise may dominate baffle noise, and the duct may also rattle passing on blower unbalance vibration noises. External blower noise is usually lower with a long duct than with a short duct, but one should not expect a really big reduction in noise just because the blower is outside instead of in the hood (for equal volumetric flow rate). (The exception would be a commercial external blower, configured deliberately so that the fan is oversized and the belt drive sheaf ratio is set for a slower tip speed.) For residential operation, where room for a silencer is available, an external roof blower and inline silencer is the quieter approach, leaving baffle hiss below normal speaking levels at full power. That is my configuration. Part of the duct turbulence noise will also be removed -- that from the duct between the silencer and the external blower. Fantech silencers are larger than the ducts, e.g., 14 inches in diameter for a 10-inch duct. http://www.fantech.net/products/fans--accessories/accessories-ventilation/silencers/ld/ld-10-silencer/ They have the general appearance of a motorcycle muffler scaled to a dragline excavator engine. The silencers are also somewhat longish, so if the duct was going to go up into an attic and straight to the roof at the roof edge, it would be necessary to use an angle duct after entering the attic to extend the duct length in the attic to accommodate the silencer, thence use another angle to bring the duct to the roof. Avoid horizontal ducting if possible. Try to make the ducting accessible if possible.