Run around coil, energy recovery calcs

[student4lyfe]

Hey all,

First post here and I was wondering if I could obtain some guidance here as I have been given a new project at my current Co-Op job.

I work under a 2nd class power engineer who is a "hands off" facilities manager, he has assigned me to work with a 3rd class engineer who is trying to prepare a report proposing a new heat recovery coil for a lab type building, a run around coil is already being for heat recovery on floors 1-5 for the building, but floors 6-8 run thru separate AHUs and does not have any heat recovery method as the building already reached a LEED standard. (Floors 6-8 were added after the fact during an addition)

I need to determine the dollar value that the owner of the building will be able to save with proposed coils, and the time till the investment pays off.
My question is.... Do I do an analysis treating the coils as two interconnected heat exchanges? What information will I need from the supplier of the unit to be able to determine the energy savings from the heat recovery coils? What calculations should I run? What info do I need?

I've never explicitly done any analysis of a heat recovery unit but am familiar with the theory and have done analysis of heat exchanges/heat pumps etc.
Just looking for some guidance as I have several ideas of how to begin but don't want to spend to long going down the wrong rabbit hole.

Also what data, specs, will I need to determine the energy savings?

I'm sure I haven't included enough info for anyone to properly answer but I can get any info as I go I just am not sure where to start i suppose.

Thanks

 

[chicopee]

If I were in your shoes, I would study the engineering behind the original installation and develop a plan of action on what you have learned. Something similar to reverse engineering. In all likelihood the cost of your new proposal will have a payback period of several years.

 

[MintJulep]

1. How much energy is available to recover?
1a. How much of that can be recovered?
2. Is there an opportunity to use the recovered energy to replace an existing energy input?
3. How much is the replaced energy worth?