Office ventilation ideas

[pjpjpjpj]

Originally Posted by jgscott987

It seems to me that you want to avoid exhausting air from the office to the outside of the house. Any air you force out of the house will have to be replaced with air that leaks in through windows, cracks, etc. Assuming the air in the office is still cooler than the air outside, you will be wasting a lot of energy cooling all of the make-up air that leaks into the house.

The best choice would be to exhaust the heated air into the AC return. A second-best option would be to exhaust the office air into another room in the house that doesn't get used much during the day. You definitely want to avoid creating a negative pressure in the house by exhausting air out.

A valid point, though the amount of air you would need to exhaust would probably be less than what forces its way into a house when the wind blows outside. Also, if your furnace or AC had cycled off (most people put the thermostat on "auto" rather than "fan"), this could (most likely would) force the hot air back out of the return vents into the house somewhere else. Not a problem in the winter, but a potential problem in the summer. It also could cause problems in the summer if you are pushing warm air through your system that had become cold from the AC - the hot air in a system that was not running could cause condensing of moisture in the ducts.

Note these are all "coulds". It might not be a problem at all. But since you'd probably only need 100-200 cfm of exhaust, it wouldn't be that big of a deal to just exhaust it. You do the same thing every time you run your bathroom fan. Waste of energy? Admittedly, yes.... but not that much.

[GKusnick]

Originally Posted by jgscott987

Assuming the air in the office is still cooler than the air outside...

I guess it depends on where you live. Here in the Northwest I've had houses where the temperature in an upstairs room in full summer sun could easily exceed the outdoor temperature.

[myoung84]

Thanks for all the comments and ideas. I have figured out that my biggest heat contributor is my non-sage PC. My Sage PC normally runs much cooler since it has better cooling fans, better case, and much more efficient power supply. I think I will try to keep that computer off since I don't really use it that often. I am also going to get a small fan to place in the doorway to pull some of the hot air out of the hot room and into the cooler hallway. I am not sure why I never thought of the fan in the door idea before. Sometimes the simplest cheapest fixes work the best.

If this doesn't work, I will start looking into the vent fans again.

[GKusnick]

Originally Posted by myoung84

I have figured out that my biggest heat contributor is my non-sage PC.

Just out of curiosity, how did you determine this? The fact that your Sage machine runs cooler doesn't necessarily mean it's producing less heat. It could just mean that it's better at moving heat out of the box (because of better airflow, for instance).

A more reliable indicator than temperature would be to measure the actual power consumed using a Kill-A-Watt or similar device. To a good approximation, power in equals heat out (since all that energy has to go somewhere).

Still, running one machine instead of two is bound to be an improvement.

[myoung84]

Originally Posted by GKusnick

Just out of curiosity, how did you determine this? The fact that your Sage machine runs cooler doesn't necessarily mean it's producing less heat. It could just mean that it's better at moving heat out of the box (because of better airflow, for instance).

A more reliable indicator than temperature would be to measure the actual power consumed using a Kill-A-Watt or similar device. To a good approximation, power in equals heat out (since all that energy has to go somewhere).

Still, running one machine instead of two is bound to be an improvement.

I determined this by feeling the air coming out of the power supply and case fans. The temperature was definitely hotter on my old PC vs. my new Core i5 Sage PC.

[Fuzzy]

I moved all my equepment into the closet of my office (built a nice enclosure there for it). I installed a small fan (actually sold as a 4" duct inline duct booster fan) and ducted it into the attic. Durring the winter, it vents back into the house through a standard register in the vaulted wall of the greeat room. During the summer, i disconnect that return, and it vents into the attic. My enclosure (which holds my network gear, 3 dish network receivers, my office desktop, and my sage server/client) has a standard HVAC style filter that it draws the air in, providing the added benefit of keeping my systems dust free as well.

[Fuzzy]

also, the temperature of the air leaving is NOT indicative of the amount of HEAT in that air. The volume of the air, as well as the humidity, all take a part. As mentioned, the best way to determine what is producing the most heat is to monitor the energy usage (as was mentioned, using something like a Kill-A-Watt). Pretty much ALL electricity used in your home ends up as heat in your home. This is true for appliances, lights, electronics, etc. Even the sound from your speakers eventually ends up as more heat in your room. In summer months, this is significant, as you end up then using even MORE electricity having to pump that heat outside (with your Air Conditioner). You can figure for every watt you use in your home, another .25 watts is used to then remove that heat. Obviously, in the winter, this isn't an issue, as that basically ends up displacing some of your heating demand.

In the end, it seems your real complaint isn't so much that the heat is being generated, but that it is all being generated in a confined space (your office). in which case, the simplest thing to do would be to just duct that heat to be spread throughout the house. Either duct it to a living room, or great room, or some large common area, or ideally, tie it into the return side of your HVAC system.

[heffneil]

iI have a small room with all my equipment and the room is brutally warm. First I had the HVAC folks put an exhaust fan right in to the return directly above the thermostat in that area. That helped but not much. Then I had the duct size increased but that didn't help. I did notice that the room is MUCH cooler when the door is open. So next week I will be installing a 6 inch duct line with an inline fan to increase the amount of air running in to the room and hopefully keep temperature stable and allowing me to close the door.

If that doesn't work I might just go with a small ductless ac system for that room...

Neil

[Fuzzy]

The exhaust fan should work just fine, but it has to have an easy source of make-up air.. That's probably why it doesn't work well with the door shut. You'll need to either undercut the door to allow greater make-up airflow, or put a vent in somewhere.

[pjpjpjpj]

Originally Posted by heffneil

iI have a small room with all my equipment and the room is brutally warm. First I had the HVAC folks put an exhaust fan right in to the return directly above the thermostat in that area. That helped but not much. Then I had the duct size increased but that didn't help. I did notice that the room is MUCH cooler when the door is open. So next week I will be installing a 6 inch duct line with an inline fan to increase the amount of air running in to the room and hopefully keep temperature stable and allowing me to close the door.

If that doesn't work I might just go with a small ductless ac system for that room...

Neil

You need to have the exhaust at the point of heat output. I don't understand your statement "directly above the thermostat"... you mean on the wall, 5 feet high? Or in the ceiling above where the room thermostat is? That's not helping - and in fact, you would be drawing that heat across your thermostat and giving false readings there.

I agree with the above, that measuring the heat in the case of your PC is not the best indicator. Heat moves by conduction, convection, and radiation - but the same amount of heat is coming out regardless of which of these forms it is in (and how much you can "feel" it). Measuring energy consumption is a better idea, because, as a co-worker likes to say, "gazintas must equal gazoutas". A small portion of the electricity put into your PC is used for the work, and the rest becomes heat. For a heat load, watts x 3.413 = Btu/h (a measure of heat).

I'll reiterate what I said above though - it is not good design practice to force hot air into a return duct unless the fan is tied to your AC unit's controls (which would then somewhat defeat the purpose of this fan). Dumping hot air into a return air system when that system might be idle can create other problems (as I posted above). Not saying it might not be fine - you may never have an issue. But as an HVAC engineer, I would never design it that way.

[ccsmoke]

Are the outside air exchangers any good? A guy at work recommended I look at one. He claims they regulate humidy from outside air, relatively cost effective, around 100 watt bulb. He also says when you get out of the shower the steam is removed almost instantly. Here in South Dakota temperature variance around 150 degrees from winter to summer months.


Having been on a remodel frenzy since last year, a mullet with a sawzall

Garage 34x30.

-installed a new gabel fan with built-in thermostat
-cut in 10 vents in soffit (was no venting in roof or soffit for garage)
-r40 in ceiling r13 in walls with vapor barrier
-10 cfl can lights with motion detection
-4 monoprice in wall speakers
-cat 6
-sheetrock

House

-New kitchen
-laminate flooring thoughout except for bedrooms new carpet there
-new central air and A-coil
-new bathroom updstairs
-working on bathroom downstairs
-new office 12 ft computer desk(laminate top and leftover cabinets from kitchen)

[heffneil]

The problem definitely is the makeup air. That is why with the door closed the room stays hot. The return is directly above the thermostat and we were attempting to trip the Ac unit more often even though that isn't the case and ultimately causes the rest of the space to too cool. I think the ultimate solution is going to be a split system through the wall that is ductless since it is a small room. We will see! Thursday I should get the make up air unit in there!

Neil

[TallMomof2]

You could also replace the solid door with a louvered one. That's what I have for the door to my furnace room which contains both a gas furnace and a gas hot water heater. The room is never too hot.

[heffneil]

I can't use a louvered door because this room is directly off my theater and the room is LOUD. It makes a significant difference when the door is closed to the noise in that room.

The room gets so quiet when the door is closed that it is apparent it is blocking air from getting in the room!

[pjpjpjpj]

Originally Posted by TallMomof2

You could also replace the solid door with a louvered one. That's what I have for the door to my furnace room which contains both a gas furnace and a gas hot water heater. The room is never too hot.

Not that it matters with regard to the other discussion here, but the louvered doors on your furnace room are not for keeping the room cool, they are to provide combustion air for the gas-fired equipment. They are likely code-required, based on the square footage of the room containing the equipment. Don't ever replace them with solid doors or block the louvers!

[valnar]

Removing heat from the room is certainly priority #1, but since it wasn't mentioned I'll add something else.

As we all know, the Sun will transfer heat through most window glass. I bought some replacement windows from a local company that utilizes a process called a "Heat Mirror" film. The glass does not get hot to the touch and not as much heat enters the room during the Summer. It might be something worth looking at.

[Fuzzy]

You can buy slightly reflective film at most home improvement stores that accomplish this.