HVAC guys - settle this argument....

[scab]

My wife always wants our master closet door closed bc she's a woman and she thinks that the closet is unsightly and messy more times than not (since, you know, everyone that comes over always tours the master suite....). I told her that she should always leave that door open bc there is a vent in the closet and I've always been told that you shouldn't close off rooms (even a walk-in closet) bc it's makes the whole system inefficient and, therefore, work harder. Then she suggested closing the vent and then closing the door which I told her was also unwise for the same reason, inefficiency.

So, am I just buying into HVAC wives tales or do I have a point? Thanks.

 

[91 zeee]

You are correct (so long as the system was designed properly to begin with).
Your unit needs to move a certain amount of air. Closing vents off reduces the amount of air it can move. It will try to force air out of the other vents; but the system should have been designed to move a specified amount of air out of each vent; therefore, best to leave it open if you can.

 

[larry_g]

Get a louvered door and you'll both have your wants satisfied.

lg
no neat sig line

 

[gregtwojeeps]

If the wife is unhappy, no one is happy

I cannot fathom why anyone would put a HVAC register in a closet. Is it a HUGE walk in closet ? Is it a supply or return register ?

 

[Gerald O]

Trim the bottom of the closet door so that there is about a 1" gap from the floor. That should give enough airflow to match the closet vent.

 

[VictorBravo]

Trim the bottom of the closet door so that there is about a 1" gap from the floor. That should give enough airflow to match the closet vent.

My first thought too.

 

[Jackfre]

40 years tells me that expecting the door to stay open is absolute folly. In your frustration, without threatening her, just kick a whole in the closet wall. She will get her door closed. make sure you use a stud finder though. From experience., again, it hurts like hell when you punch the wood.

 

[brewchief]

Does the system work OK with the door closed? I always put a heat run in a walk in closet but I fully expected it to get closed or covered anyways.

One closed grill in a closet should have zero impact on how efficient the rest of the system is, closing off a couple rooms certainly could however.

 

[CWO4GUNNER]

Well we all know all taught, ideally system load design should be unrestricted or it could place a load on the blower. In the real world an I say this as a landlord HVAC tech that tenants do it to save money and it has never hurt my systems. I mean its not like I recommend it, on the contrary I explain that it wont notice any saving, but they swear that closing vents to bathrooms and master closets makes the AC work much better in the living and bedrooms and saves money. I tell them OK just don't do that to any other rooms and most importantly do not use a pleated high density filter on the return. And in reality while most exhaust vents are designed to leak like a sieve and having a couple close will do no harm, a return air vent laboring under a high flow dirty filter or using a clean high density filter will place a load on the blower and if lucky only damage the capacitor.

If the installers didn't consider having the doors undercut so they can be closed as part of the system build, they probubly diden't do any heat gain calculations or install ducting for max static pressure anyway.

Its the return that really needs to have free flow without restriction to prevent damage as most are improperly undersized anyway.

 

[scab]

Cool, thanks for all the replies.

 

[bushmechanic]

Get a louvered door and you'll both have your wants satisfied.

lg
no neat sig line

This is the appropriate solution to your problem.

 

[sourdough]

If the installers didn't consider having the doors undercut so they can be closed as part of the system build, they probubly diden't do any heat gain calculations or install ducting for max static pressure anyway.

Do you really think the mechanical folks have any serious talks with the carpenters about airflow?

 

[CWO4GUNNER]

Do you really think the mechanical folks have any serious talks with the carpenters about airflow?

No... but most planned community builders, or in high end custom build homes the architectural plans include them. I must say though that in homes where that is not the case it is impressive to show off to visitors that when you turn on the air handler all the doors in the home automatically slam shut, which can be passed off as a modern security feature built into the AC.

 

[skyking]

Get a louvered door and you'll both have your wants satisfied.

lg
no neat sig line

Larry is right have some kind of vent in the door . And never, ever try to reason with a woman !!!!!!!

 

[y'sguy]

You are correct (so long as the system was designed properly to begin with).
Your unit needs to move a certain amount of air. Closing vents off reduces the amount of air it can move. It will try to force air out of the other vents; but the system should have been designed to move a specified amount of air out of each vent; therefore, best to leave it open if you can.

Yah, well he might be correct. science, stats etc. an all, BUT it still won't matter to the wife. So, prepare to give it up. Being right in this case isn't going to help his everyday life.

 

[brewchief]

No... but most planned community builders, or in high end custom build homes the architectural plans include them. I must say though that in homes where that is not the case it is impressive to show off to visitors that when you turn on the air handler all the doors in the home automatically slam shut, which can be passed off as a modern security feature built into the AC.

I've been the HVAC installer on probably 150+ homes, from 800 sq feet to 6000+sq feet and I've never seen anything more on a set of plans then a rubber stamp that says " The HVAC contractor is to design and install a suitable system" or something pretty close to that.

The planned community builders like Pulte and Toll bros might have a simple set of plans since they build the same house 5,000 times a year but they will use the absolute cheapest company they can find to install it and it shows.

Commercial jobs will have a complete HVAC design and layout and you may get the same in some multi-million dollar residential jobs but HVAC plans for an average house are as rare as bigfoot at least in my area.

 

[Onewolf]

...snip....

I cannot fathom why anyone would put a HVAC register in a closet. Is it a HUGE walk in closet ? Is it a supply or return register ?

We have 'his' and 'hers' walk-in closets in the master suite. Both have HVAC supplies. In Florida it's important to keep the air moving to reduce the potential for humidity build-up (in our house they are next to the master bathroom).

 

[CWO4GUNNER]

I've been the HVAC installer on probably 150+ homes, from 800 sq feet to 6000+sq feet and I've never seen anything more on a set of plans then a rubber stamp that says " The HVAC contractor is to design and install a suitable system" or something pretty close to that.

The planned community builders like Pulte and Toll bros might have a simple set of plans since they build the same house 5,000 times a year but they will use the absolute cheapest company they can find to install it and it shows.

Commercial jobs will have a complete HVAC design and layout and you may get the same in some multi-million dollar residential jobs but HVAC plans for an average house are as rare as bigfoot at least in my area.

Oh brother...I said it was mostly dong wrong didn't I. There are exceptions you know.

 

[Falcon67]

We use something similar in the 3rd bedroom as it's farthest from the return and is always a little too warm or too cool. It's fed by a 6" duct, probably needs an 8. There are two other taps (small bath, 10x11 room) off the 10" line that runs to that side of the house.

FWIW, I had to fight my wife for a vent in the laundry/closet at the old house. 10x12 room with no vent and two outside walls with little or no insulation - just asking for it.

http://www.homedepot.com/p/Battic-D...src=17588969&gclid=CMDdtJ6Q9cACFYMF7Aod1DoA-A

 

[Freejack]

Scab - Does your HVAC system have a PSC-type blower motor, or an ECM blower motor running constant Volume? If it is the latter, the even if you restrict that one vent (not a big deal anyway), the motor will increase output to ensure your have adquate CFM for the system at the higher static.

Well we all know all taught, ideally system load design should be unrestricted or it could place a load on the blower.

Though it seems counter intuative, for a HVAC with a forward curve blower, restricting a vent (or return) increases the static pressure, reducing the CFM, which in turn, reduces the load on the motor at least for standard PSC induction motors. Most ECMs have software that increases fan output to maintian airflow

The real impact to reduced airflow is that the whole system may be working less efficienctly with less airflow. Most residential A/C systems are designed around 400 CFM per ton capacity.

Jake

 

[CWO4GUNNER]

No disagreement here... I'm just sharing what as a 11 year landlord I have learned based on cause and effect in the area of tenant intervention of air flow. End result bottom line is I have learned to supply my tenants with packages of high-flow return air filters and require their use. The cause and effect has been a marked and noticeable decrease in AC DIY service calls in summer, that'senough for me anyway. Forgive me if I sounded too authoritative, now I'll probably get a call today.

 

[pseudorealityx]

****** filtration is a bandaid to poor design, not a 'solution'.

 

[CWO4GUNNER]

****** filtration is a bandaid to poor design, not a 'solution'.

Agreed! Not just contracted design, but previous contract service as well. Since then Iv saved enough to replace them in the near future with the type care and consideration that only a DIY owner can give.