Fan coil units - 19 ft. ceilings

[Designer_82]

Have a project with a large worship room with 19 ft. drop ceilings


My HVAC engineer says fan coil units don't provide enough power for this height.

Would like to check if you agree with this?

Thanks

 

[Snickster]

Check with manufacturer for throws and maximum recommended height.

 

[nuuvox000]

I don't know if you're an owner rep or something but typically, when people get involved with my HVAC designs, they either 1) make them more expensive than needed or 2) go in a direction that is going to cause them trouble down the road. If your HVAC engineer is a PE, you're probably better off just trusting them.

Anyway, getting to your question: by power, do you mean throw? If they're ducted, one could easily design some duct and diffusers that can throw 19 ft. Of course, this is in my imagination where I've filled in all of the constraints and assumptions that you didn't give. If they're not ducted, you could possibly use HVLS fans but personally, I try to avoid those.

 

[HVAC-Novice]

A fan-coil unit is just a simplified AHU. You can have them with varying capacities inc. higher pressure and flow needed for far throw.

How the design would work basically is you select the diffusers for the height and flowrate required. Diffuser manufacturer can give you spread numbers that are based on temperatures, how far they throw to have 50 fpm velocity and so on. then you will get a pressure drop for those conditions and diffuser. That along with the ductwork. filters etc. requires the pressure produced by fan. As long as the FCU can be selected with a fan large enough, the diffuser doesn't care if the air comes from a larger AHU, or an FCU.

But really, if you hired an engineer and trust them, let them design. If you don't trust them, hire someone you trust. We are just people on the Internet and know nothing about your situation. That engineer (hopefully) analyzed the situation and available equipment and your budget - we didn't.

 

[ProcessHVAC]

As long as you have enough throw, 19 ft should not be an issue.

 

[MintJulep]

Are you looking for something like this?

https://www.modinehvac.com/products...-heaters/vertical-hydronic-v/#FeaturesOptions

 

[dbill74]

It is really hard to say without additional information. One of my first questions is how large is large?
What exactly are you calling "Fan Coil Unit"? When I hear FCU I think a split Dx or chilled water unit with a maximum capacity around 15 - 20 tons and can fit in closet. Often comes as packaged unit.

For something like a "large worship room" I'm thinking a larger "air handling unit" is needed capable of 50-75+ tons of cooling. Such a unit often comes in sections and needs a bigger mechanical room to be located in.

To answer your question specifically: maybe, it depends.