will closing some of the vents help with Heat/AC bills?

[Semidevil]

We have central air at our house and every room has vents for the heat and/or AC to go. I would think that there is no need to have heat/AC in the laundry room, guest bathroom, or even the master bathroom.

Will closing these vents help reduce energy bills in any way?

 

[wedi42]

closing the vents will save some $, if you close the door to that room.

 

[XZeroII]

If you close the doors to keep the heat out, then yes it would help a bit.

 

[Jumpem]

You want to keep some of those rooms heated to keep water pipes from freezing.

 

[jlee]

Originally posted by: Jumpem
You want to keep some of those rooms heated to keep water pipes from freezing.

I don't think his interior doors and walls will maintain a 30-40f+/- temperature difference between adjacent rooms..

 

[Dirigible]

I posted a similar question earlier this month. Lemme look for it...

Here it is:
http://forums.anandtech.com/me...id=38&threadid=2129408

I don't think we got hard numbers or a definitive answer, but I ended up closing the vents in my attic. It's a little cooler up there now, and I'm hoping it'll save at least a little in heating costs.

 

[Jumpem]

Originally posted by: JLee
I don't think his interior doors and walls will maintain a 30-40f+/- temperature difference between adjacent rooms..

My parents had their kitchen pipes freeze and rupture from having the heat too low.

 

[SacrosanctFiend]

No. Your system is designed to output a certain amount of CFMs. By closing a vent, the CFMs will transfer to another vent. What you need is an updated thermostat or better Zone Control. You may, actually, cost youself more money in the long run by closing vents as the system would run the same, but encounter problems distributing all of the air. Restricting the output may cause your unit to freeze up or kick out on overload.

Disclaimer: I don't know too much about HVAC, my knowledge comes from my father who has been in HVAC industry for 24 years.

 

[jersiq]

Originally posted by: SacrosanctFiend
No. Your system is designed to output a certain amount of CFMs. By closing a vent, the CFMs will transfer to another vent. What you need is an updated thermostat or better Zone Control. You may, actually, cost youself more money in the long run by closing vents as the system would run the same, but encounter problems distributing all of the air. Restricting the output may cause your unit to freeze up or kick out on overload.

Disclaimer: I don't know too much about HVAC, my knowledge comes from my father who has been in HVAC industry for 24 years.

If that is true, why do they make vents adjustable?
I had collars put on my Central Air when I had my house, never had any sort of problem.

 

[Rubycon]

There's a couple things at work here and a few things to consider. If your ductwork is "tight" as in minimal leaks (no panned plenums, etc.) then closing off the vent will afford higher pressure on the supply trunk and deliver slightly more air to the neighboring vents. It should not be detrimental to the indoor blower fan - most residential "squirrel cage" blowers actually "load down" under a higher static discharge pressure. Thus if you're measuring amps on the motor it will go DOWN as the pressure goes up. (from closing off vents)

With a heat pump it's important to maintain airflow over the indoor coil above the minimums as this component in the heating cycle is now the condenser. Higher condenser temperatures equal higher head pressures which means the compressor will pull more amps negating your savings. Also too high a head pressure will trip the high head pressure switch and if this component is not an auto resetting type you fall back on auxiliary heat which in the case of strip heaters - is expensive!

As for air balance, variable air volume (VAV) using pressure sending units downstream of the main fan, fan vortices and variable speed fans* are in use due to complexity of maintenance, setup, expense, etc. If that was the case you could just zone off that area and be done with it. [* variable speed fans are in residential settings but not as a component of VAV control.]

Finally if there are outside walls that have pipes carrying water that sits still; freezing is a definite possibility. Again, this really depends on your climate.

 

[akshatp]

Originally posted by: Rubycon
There's a couple things at work here and a few things to consider. If your ductwork is "tight" as in minimal leaks (no panned plenums, etc.) then closing off the vent will afford higher pressure on the supply trunk and deliver slightly more air to the neighboring vents. It should not be detrimental to the indoor blower fan - most residential "squirrel cage" blowers actually "load down" under a higher static discharge pressure. Thus if you're measuring amps on the motor it will go DOWN as the pressure goes up. (from closing off vents)

With a heat pump it's important to maintain airflow over the indoor coil above the minimums as this component in the heating cycle is now the condenser. Higher condenser temperatures equal higher head pressures which means the compressor will pull more amps negating your savings. Also too high a head pressure will trip the high head pressure switch and if this component is not an auto resetting type you fall back on auxiliary heat which in the case of strip heaters - is expensive!

As for air balance, variable air volume (VAV) using pressure sending units downstream of the main fan, fan vortices and variable speed fans* are in use due to complexity of maintenance, setup, expense, etc. If that was the case you could just zone off that area and be done with it. [* variable speed fans are in residential settings but not as a component of VAV control.]

Finally if there are outside walls that have pipes carrying water that sits still; freezing is a definite possibility. Again, this really depends on your climate.

Damn girl you got crazy knowledge! How do you know so much about so many different topics??

 

[SacrosanctFiend]

Originally posted by: jersiq

Originally posted by: SacrosanctFiend
No. Your system is designed to output a certain amount of CFMs. By closing a vent, the CFMs will transfer to another vent. What you need is an updated thermostat or better Zone Control. You may, actually, cost youself more money in the long run by closing vents as the system would run the same, but encounter problems distributing all of the air. Restricting the output may cause your unit to freeze up or kick out on overload.

Disclaimer: I don't know too much about HVAC, my knowledge comes from my father who has been in HVAC industry for 24 years.

If that is true, why do they make vents adjustable?
I had collars put on my Central Air when I had my house, never had any sort of problem.

No idea why they make them adjustable. When I ran loads, I mostly dealt with hospital and dialysis centers, neither of which had adjustable vents, only distributors.

 

[akshatp]

Originally posted by: SacrosanctFiend

Originally posted by: jersiq

Originally posted by: SacrosanctFiend
No. Your system is designed to output a certain amount of CFMs. By closing a vent, the CFMs will transfer to another vent. What you need is an updated thermostat or better Zone Control. You may, actually, cost youself more money in the long run by closing vents as the system would run the same, but encounter problems distributing all of the air. Restricting the output may cause your unit to freeze up or kick out on overload.

Disclaimer: I don't know too much about HVAC, my knowledge comes from my father who has been in HVAC industry for 24 years.

If that is true, why do they make vents adjustable?
I had collars put on my Central Air when I had my house, never had any sort of problem.

No idea why they make them adjustable. When I ran loads, I mostly dealt with hospital and dialysis centers, neither of which had adjustable vents, only distributors.

Im assuming they are adjustable for people who dont want their room as hot/as cold as the rest of the house.

 

[SacrosanctFiend]

Originally posted by: akshatp

Originally posted by: SacrosanctFiend

Originally posted by: jersiq

Originally posted by: SacrosanctFiend
No. Your system is designed to output a certain amount of CFMs. By closing a vent, the CFMs will transfer to another vent. What you need is an updated thermostat or better Zone Control. You may, actually, cost youself more money in the long run by closing vents as the system would run the same, but encounter problems distributing all of the air. Restricting the output may cause your unit to freeze up or kick out on overload.

Disclaimer: I don't know too much about HVAC, my knowledge comes from my father who has been in HVAC industry for 24 years.

If that is true, why do they make vents adjustable?
I had collars put on my Central Air when I had my house, never had any sort of problem.

No idea why they make them adjustable. When I ran loads, I mostly dealt with hospital and dialysis centers, neither of which had adjustable vents, only distributors.

Im assuming they are adjustable for people who dont want their room as hot/as cold as the rest of the house.

Sounds good, but the excess load has to go somewhere.

 

[Capt Caveman]

Originally posted by: SacrosanctFiend

Originally posted by: akshatp

Originally posted by: SacrosanctFiend

Originally posted by: jersiq

Originally posted by: SacrosanctFiend
No. Your system is designed to output a certain amount of CFMs. By closing a vent, the CFMs will transfer to another vent. What you need is an updated thermostat or better Zone Control. You may, actually, cost youself more money in the long run by closing vents as the system would run the same, but encounter problems distributing all of the air. Restricting the output may cause your unit to freeze up or kick out on overload.

Disclaimer: I don't know too much about HVAC, my knowledge comes from my father who has been in HVAC industry for 24 years.

If that is true, why do they make vents adjustable?
I had collars put on my Central Air when I had my house, never had any sort of problem.

No idea why they make them adjustable. When I ran loads, I mostly dealt with hospital and dialysis centers, neither of which had adjustable vents, only distributors.

Im assuming they are adjustable for people who dont want their room as hot/as cold as the rest of the house.

Sounds good, but the excess load has to go somewhere.

Wouldn't the excess load go to the vents that offered less resistance(vents that were open more)?

 

[Rubycon]

Originally posted by: Capt Caveman

Wouldn't the excess load go to the vents that offered less resistance(vents that were open more)?

In theory it would but ductwork especially residential - is quite leaky.

Someone with a balometer or hood should try getting a few readings from adjoining vents and grab a reading from the vent they're shutting down then go back and take the neighboring readings. The delta will probably surprise you!

Originally posted by: akshatp

Damn girl you got crazy knowledge! How do you know so much about so many different topics??

I have smart neighbors.

 

[OhSnap688]

What my dad does is during the winter close the vents of the upstairs rooms, since heat rises apparently. It seems to work

 

[pontifex]

Originally posted by: akshatp

Originally posted by: Rubycon
There's a couple things at work here and a few things to consider. If your ductwork is "tight" as in minimal leaks (no panned plenums, etc.) then closing off the vent will afford higher pressure on the supply trunk and deliver slightly more air to the neighboring vents. It should not be detrimental to the indoor blower fan - most residential "squirrel cage" blowers actually "load down" under a higher static discharge pressure. Thus if you're measuring amps on the motor it will go DOWN as the pressure goes up. (from closing off vents)

With a heat pump it's important to maintain airflow over the indoor coil above the minimums as this component in the heating cycle is now the condenser. Higher condenser temperatures equal higher head pressures which means the compressor will pull more amps negating your savings. Also too high a head pressure will trip the high head pressure switch and if this component is not an auto resetting type you fall back on auxiliary heat which in the case of strip heaters - is expensive!

As for air balance, variable air volume (VAV) using pressure sending units downstream of the main fan, fan vortices and variable speed fans* are in use due to complexity of maintenance, setup, expense, etc. If that was the case you could just zone off that area and be done with it. [* variable speed fans are in residential settings but not as a component of VAV control.]

Finally if there are outside walls that have pipes carrying water that sits still; freezing is a definite possibility. Again, this really depends on your climate.

Damn girl you got crazy knowledge! How do you know so much about so many different topics??

i think she's a robot or she's like plugged into the internet through some kind of neural network type of shit. it almost seems like she's pulling this out of some kind of book ro something, lol.

has she ever posted pics? I think we need proof that she is in fact a human. And if she's as hot as she is smart - then damn, let me give you my address! lol

 

[FoBoT]

not much
make sure you have enough insulation

 

[Wag]

This year my electric company allowed me to switch power supplier so I save a few cents per kilowatts now.