Air ventilation for basement HT

[jayad08]

Hi,
My HT setup is in a basement, which does not have any sort of ventilation mechanism except the air coming in from the stairs leading down and another small exhaust window opening. But both of these are not really useful as during movie watching I close all the openings to reduce the sound volume outside. During other times, the room remains closed so that dust does not enter..
All in all it is suffocating at times, with the stale air..
My initial plan was to install an AC, but after checking the mechanism of how AC works, I have dropped the idea..
From what I have come to know is that AC recirculates the same air inside the room, does not add any fresh air from outside. <Experts, please correct me on this if wrong>

I thought of putting multiple exhaust fans (CATA silent).. but that again introduces problems of sound volume due to multiple openings, also does not provide fresh air source, rather would clear stale air.

Now I am thinking of installing .75HP centrifugal fan on the ground floor which would pump clean air to the basement through an inlet..and would be noise free also.. but this solution is costing me more than 12-15k..
has anybody got better ideas?

 

[avidyarthy]

The centri fan is about the only practical thing that would work .... more so, when noise is a factor.

Just keep in mind that the air duct is done proper and is leakfree, else the leak points would act to dilute the static pr created by the fan resulting in less amount of air being pumped out.

This mechanism would create a forced negative draft in your HT room, which would automatically bring in the outside fresh air ...... Yes, the entire contrap would set you back by 10-15k.

 

[jayad08]

The centri fan is about the only practical thing that would work .... more so, when noise is a factor.

Just keep in mind that the air duct is done proper and is leakfree, else the leak points would act to dilute the static pr created by the fan resulting in less amount of air being pumped out.

This mechanism would create a forced negative draft in your HT room, which would automatically bring in the outside fresh air ...... Yes, the entire contrap would set you back by 10-15k.

Thanks..
There is a small doubt.. i was actually thinking of pumping fresh air into the basement from the centri fan rather than pulling the stale air out ..
would that be a problem?

also should i add a single exhaust to pump the extra air out from the basement when the centri fan pushes it?

 

[avidyarthy]

Thanks..
There is a small doubt.. i was actually thinking of pumping fresh air into the basement from the centri fan rather than pulling the stale air out ..
would that be a problem?

also should i add a single exhaust to pump the extra air out from the basement when the centri fan pushes it?

Answering your 1st part ..... if you need low dust solution, then you have to add a particulate filter at the fan inlet, if you want to throw fresh air inside. That would get complicated. For a home use, you can do without complications. Who would design for you?

So, suggest live with a bit of Delhi dust and suck out the stale air instead. NO need to bring in fresh air. It would automatically come in.

Just make sure:
1. The intake port of the air suction point/s is/are away from your entry door. Should be as far away from the door as possible ... to avoid an air short circuit.

2. Select a fan with a TSP (total static pressure) of @ 25 mmWC or 1"

3. Fan capacity? ..... require room size ... but, not that critical .... the lowest size centri would be fine..... say, between 1000 - 2000 CFM.

 

[partymonger]

What you have heard about the AC is wrong, it is a good option.

 

[jayad08]

What you have heard about the AC is wrong, it is a good option.

I was getting confused by the following line mentioned in the article
Air conditioner - Wikipedia, the free encyclopedia

"Unlike window ACs the split AC does not have an option of exchange of indoor and outdoor air."

 

[avidyarthy]

In mostly all window ACs (good brands) you would find an adjustable port in the blower section which either allows for outside air to come in or inside air to be exhausted out. But, from experience, have found only the fresh air intake route has "some" effect.

This is not possible in a split unit AT ALL.... as the ports cannot be put... it is plain simple recirculation cooling.

In a way, a window AC is a more practical choice than a split unit due to that feature.

But, in your case, you have to physically throw out 'quite' an air volume to have a meaningful effect of ventilation. Hence, the centri route is fine.

A very very exact solution would have been to incorporate an HRW (heat recovery wheel) along with air conditioning for total climate control. Google HRW or its full form to know about it. Would be quite expensive though, for just a small HT room.

 

[jayad08]

In mostly all window ACs (good brands) you would find an adjustable port in the blower section which either allows for outside air to come in or inside air to be exhausted out. But, from experience, have found only the fresh air intake route has "some" effect.

This is not possible in a split unit AT ALL.... as the ports cannot be put... it is plain simple recirculation cooling.

In a way, a window AC is a more practical choice than a split unit due to that feature.

But, in your case, you have to physically throw out 'quite' an air volume to have a meaningful effect of ventilation. Hence, the centri route is fine.

A very very exact solution would have been to incorporate an HRW (heat recovery wheel) along with air conditioning for total climate control. Google HRW or its full form to know about it. Would be quite expensive though, for just a small HT room.

@avidyarthy ..thanks again.. so the ac option is definitely out..
can you provide some useful links for the same.. with google i didnt get expected results..
also since you are based in delhi and are in related business.. can you point me some dealers for centri fans and possible options/costing for HRW