Cooling

[hucker]

My media closet can get pretty warm and it is only going to get worse when I move a couple of PC's in there. The cold air return goes right through the room. Is there any reason I shouldn't put a manual (or controllable) vent in the cold air return ducting to suck some hot air out? I could undercut the door or put a vent trough the wall.

 

[brotsten]

My media closet can get pretty warm and it is only going to get worse when I move a couple of PC's in there. The cold air return goes right through the room. Is there any reason I shouldn't put a manual (or controllable) vent in the cold air return ducting to suck some hot air out? I could undercut the door or put a vent trough the wall.

I have a wiring closet that was designed into the house. It's controlled on the same zone as my theater. The heating contractor calculated the cfm needed based on the amperage of my equipment. The room has two supply registers and one return which we mounted directly under my two 19" racks so the air is drawn through them.

We also installed a remote exhaust fan for the projector that dumps into the return.

So far, so good.

Brian

 

[hucker]

I have a wiring closet that was designed into the house. It's controlled on the same zone as my theater. The heating contractor calculated the cfm needed based on the amperage of my equipment. The room has two supply registers and one return which we mounted directly under my two 19" racks so the air is drawn through them.

We also installed a remote exhaust fan for the projector that dumps into the return.

So far, so good.

Brian

I don't have AC in the house. I'm just trying to suck out the hot air and move it into the house.

 

[mdesmarais]

I'd be a little careful- you can mess up your balance by cutting into the return. If you do decide to do it, you will also need to allow the air from the registers into the room somehow- maybe a grill in the door?- or nothing will happen. There needs to be a source for the air to come from.

 

[brotsten]

I have a wiring closet that was designed into the house. It's controlled on the same zone as my theater. The heating contractor calculated the cfm needed based on the amperage of my equipment. The room has two supply registers and one return which we mounted directly under my two 19" racks so the air is drawn through them.

We also installed a remote exhaust fan for the projector that dumps into the return.

So far, so good.

Brian

I don't have AC in the house. I'm just trying to suck out the hot air and move it into the house.

I have a heatpump, so the temperature at the supply registers is only ~85 degrees. At that temperature, the system works when the heat is on. It's also setup to circulate the ambient air when it's not running, during those times I'm using ~70 degree supplies. This system wouldn't work with a gas or electric forced air. But, if you are drawing ambient air it should.

Like mdesmarais said though, the system should have been designed to supply and return air properly throughout the entire house. I wouldn't think a small closet would have much effect, but I never make mistakes.

Brian

 

[CollinR]

Another thing is you should have means to stop it if there is a fire, otherwise you have made a residential toxic gas distribution system.

 

[hucker]

Another thing is you should have means to stop it if there is a fire, otherwise you have made a residential toxic gas distribution system.

If I put access to the CAR I'll definitely put an inlet vent in. What is nice is that the CAR is at the ceiling of the closet so it will grab the hot air. I already have my HomeVision setup to shutdown that HVAC and all exhaust fans in the event of smoke detection so I think I have this covered.

 

[politics123]

Another thing is you should have means to stop it if there is a fire, otherwise you have made a residential toxic gas distribution system.

If I put access to the CAR I'll definitely put an inlet vent in. What is nice is that the CAR is at the ceiling of the closet so it will grab the hot air. I already have my HomeVision setup to shutdown that HVAC and all exhaust fans in the event of smoke detection so I think I have this covered.

I'd strongly advise you not to add a new intake into the CAR. They *should* be sized to balance out flows. If you do "need" to do this, get a Manual D and remap your returns and supplies. Otherwise, you risk affecting your overall system's health and usefulness. (eg: you may no longer cool an existing area of the house because there is not adequate suction in the CAR in that room)


Where are the existing returns? Nearby? Why not just add a couple fans (one at ground level to push air in, one above the header to push air out). Alternatively, reduce your heat by removing the power supplies and putting them elsewhere, etc.

 

[hucker]

Another thing is you should have means to stop it if there is a fire, otherwise you have made a residential toxic gas distribution system.

If I put access to the CAR I'll definitely put an inlet vent in. What is nice is that the CAR is at the ceiling of the closet so it will grab the hot air. I already have my HomeVision setup to shutdown that HVAC and all exhaust fans in the event of smoke detection so I think I have this covered.

I'd strongly advise you not to add a new intake into the CAR. They *should* be sized to balance out flows. If you do "need" to do this, get a Manual D and remap your returns and supplies. Otherwise, you risk affecting your overall system's health and usefulness. (eg: you may no longer cool an existing area of the house because there is not adequate suction in the CAR in that room)


Where are the existing returns? Nearby? Why not just add a couple fans (one at ground level to push air in, one above the header to push air out). Alternatively, reduce your heat by removing the power supplies and putting them elsewhere, etc.

The return vent is right outside the media closet. I *could* exhaust the air right next to the vent and have it suck it back in. That would work but wouldn't look so nice since it would put more vents in the hall way. Perhaps I could get a larger vent grill and have the right side of the grill be the exhaust and the rest be the CAR.

 

[pete]

As long as you keep the additional vent small (say 10x4 max) you'll be fine . . you can get a supply register at you local home center (with a manual damper) . . just cut a hole in the duct an screw the register on . . you''ll need about 1.5in clear under a 30"w door (this set up will move about 150cfm) . .

but what about during the summer ? . . another idea would be install a small exhaust fan (vented outside) . .


Pete C

(20+ yrs HVAC draftsman)

 

[politics123]

Tell me something about the furnace. Is it high-efficiency? (is there supply air provided?) Look at the furnace. Are there 2 PVC pipes coming to it, or only one, or none? Does there look to exist a chimney?

 

[hucker]

Tell me something about the furnace. Is it high-efficiency? (is there supply air provided?) Look at the furnace. Are there 2 PVC pipes coming to it, or only one, or none? Does there look to exist a chimney?

Yes it is high efficiency.