Eng-Tips is the largest engineering community on the Internet
Intelligent Work Forums for Engineering Professionals
Research topic ideas
- Thread starter hmurya
- Start date
- Thread starter
- #4
@GT-EGR
There already is a project that I worked on, and had the hardest time dealing with FAHUs because of how the building is shaped and the amount of space I have as every single equipment went into the basement due to lack of a proper roof. and the building that had a roof, just the footprint was small enough that it created issues with fahu placement and duct runs.
I work in UAE, so its moving more towards compact buildings (mainly due to European architects being employed for design). Those guys are in the habit on design buildings that have smaller varying footprints which I guess seems fine by European standards, but the Middle East standards and requirements are a lot harsher. We have to drop temperatures from 45-55C to 20C (we design our outdoor air at 34/32C due to high humidity. for example it takes 250kW of energy to cool 7000LPS and due to FAHU restrictions I can't match the output to 18C/50%-60% RH. Usually selections come in at an RH of 70-80) so the cooling coil size increases by a lot and hence the overall equipment becomes large (I have FAHUs that are as long as 7meter that provide 7000LPS of fresh air).
@MintJulep optimize the supply of fresh air and the size of handling units. i looked at IDEC systems. for that. I wanted to know if there are other ways something like that can be achieved without occupying 70-100m2 of area to place the FAHUs and their ducts.
There already is a project that I worked on, and had the hardest time dealing with FAHUs because of how the building is shaped and the amount of space I have as every single equipment went into the basement due to lack of a proper roof. and the building that had a roof, just the footprint was small enough that it created issues with fahu placement and duct runs.
I work in UAE, so its moving more towards compact buildings (mainly due to European architects being employed for design). Those guys are in the habit on design buildings that have smaller varying footprints which I guess seems fine by European standards, but the Middle East standards and requirements are a lot harsher. We have to drop temperatures from 45-55C to 20C (we design our outdoor air at 34/32C due to high humidity. for example it takes 250kW of energy to cool 7000LPS and due to FAHU restrictions I can't match the output to 18C/50%-60% RH. Usually selections come in at an RH of 70-80) so the cooling coil size increases by a lot and hence the overall equipment becomes large (I have FAHUs that are as long as 7meter that provide 7000LPS of fresh air).
@MintJulep optimize the supply of fresh air and the size of handling units. i looked at IDEC systems. for that. I wanted to know if there are other ways something like that can be achieved without occupying 70-100m2 of area to place the FAHUs and their ducts.
How about researching possible evaporator coil designs tailored toward the challenging latent vs sensible heat loads you encounter?
Or maybe the possibility of two evaporator coils in series, one designed to deal with much of the latent load, and a second to do the final conditioning?
This paper might give you some ideas.
Or maybe the possibility of two evaporator coils in series, one designed to deal with much of the latent load, and a second to do the final conditioning?
This paper might give you some ideas.
Maybe you could look at optimizing your fresh air percentage to reduce plant load?
In NA, we can use a ASHRAE 62.1 calculation spreadsheet which accounts for unused fresh air in the return from over ventilated spaces such as store rooms. The calculation allows for the unused fresh air to contribute to your overall fresh air, thus reducing the amount you need to bring into the building. This might be an interesting topic for you.
In NA, we can use a ASHRAE 62.1 calculation spreadsheet which accounts for unused fresh air in the return from over ventilated spaces such as store rooms. The calculation allows for the unused fresh air to contribute to your overall fresh air, thus reducing the amount you need to bring into the building. This might be an interesting topic for you.
How about compressing the fresh air?Compressor footprints will be much smaller.Small dia pipes can be used instead of ducts.It is much easier to knock moisture out of compressed air.Some useful work can be done(such as driving a fan) during the expansion back to atmospheric pressure prior to room delivery!
- Thread starter
- #8
@mintjulep thanks for that. i will look into that.
@lukaieng what sheet are you exactly talking about. we do use ASHRAE values but say for example store rooms and such dont make up the majority or even a small minority of the system. Unless I am not understanding this correctly.
@SAK9 ok well. that looks interesting. but for some reason whatever i find online talks about combusting the air after compression. what exactly should i be searching for to get a better idea for it
@lukaieng what sheet are you exactly talking about. we do use ASHRAE values but say for example store rooms and such dont make up the majority or even a small minority of the system. Unless I am not understanding this correctly.
@SAK9 ok well. that looks interesting. but for some reason whatever i find online talks about combusting the air after compression. what exactly should i be searching for to get a better idea for it
This is the most user friendly version I know of.
The calculation does a good job of applying occupant diversity to reduce the OA percentage as well.
The calculation does a good job of applying occupant diversity to reduce the OA percentage as well.
- Status
Similar threads
- Locked
- Question