Controlling hvac to a single room

[mike93lx]

My home office (where I work from full time) has some hvac challenges. Due to low air flow when cooling, we increased the size of the duct feeding the room (to 8"), which helped, but it's resulting in the room getting way too warm when the heat is on. I currently regulate flow with a box that blocks the floor register when it gets too warm. I want something better.

I don't really need to be able to control the furnace from here, but I'd like to at least control air flow, so I was thinking a motorized damper that is tied to a thermostat in the room. Anyone have experience with something like this?

 

[yeldogt]

You can easily do that with a simple set up ..... they make room vents that will do this as well with wireless thermostats (I have never used)

Sometimes a simple manual damper will work and you just flip it from winter to summer .... you can also get the powered damper and set it up so it does not close all the way and have the thermostat control it fully open .... since it's going to always need some heat or cool having some bleed will work better. They just work off 24 volts and most spring closed

 

[larry4406]

I recall a This Old House episode where they had individual registers with dampers as yeldogt described.

The dampers were WiFi and connected to a thermostat. I think there were also remote temperature sensors (also WiFi) so the house could be zoned.

 

[FredWanaker]

just get an adjustable floor register. You can also get a style that goes inside the register box if you have a fancy register cover. Also, make sure there is clearance under the door for air to leave, or a return air duct. If there isn't, closing the door will also change how the HVAC works in that room.

 

[mike93lx]

I have floor registers with dampers and they are a pain in the *** to use, plus not automated

The duct is in my crawl space, so manually adjusting a damper in the duct is not desirable either.

I don't have a return in the space and won't be adding one. Closing the door does hurt performance, which is why we upped the duct size. When the kids aren't home, the door is generally open.

Does anyone have recommendations on a particular damper and thermostat? I've been looking at Honeywell on supply house, but I just started the search

 

[LS6 Tommy]

Sorry, but adding a stat controlled damper is not a good way to solve your issue. A fairly low buck solve would be an ecobee stat with a zone/occupancy sensor in your office. The system will only run until your office meets setpoint.

Tommy

 

[mike93lx]

Sorry, but adding a stat controlled damper is not a good way to solve your issue. A fairly low buck solve would be an ecobee stat with a zone/occupancy sensor in your office. The system will only run until your office meets setpoint.

Tommy

That won't work. The office hits temp way before the rest of the house, so everything else will be cold. I already have a remote sensor for my nest that I can move in there if I am home alone, problem is, that isn't all that often.

I need to regulate that room without impacting the rest of the house.

 

[yeldogt]

From the OP's description I'm assuming he has no desire to control any of the equipment in the houses .... just trying to modulate (down) what is now coming to the room with the larger duct. You don't need anything special ..... just make sure the damper's closed position can be manually adjusted. Download the manual. IMO you will want it set up so it does not close all the way ... setting it so the room will end up just colder than the rest of the house when closed will save some BTU's when the room is not used .... when it is occupied the thermostat will adjust. and allow more flow. Having it full on and off does not work as well.

When I design a duct system for my own projects I always oversize the master bedroom. This may be done using larger ducts/vents or by adding an additional one. I don't increase the return -- the net here is I can naturally increase the extreme of the bedroom. IE: With the door closed it is colder in the summer and warmer in the winter vs the rest of the house. So with a small setback in the rest of the house at night the bedroom does not change as much ... with the door open the room will stabilize. Having simple manual dampers in one or more of the trunks is an easy way to adjust whatever you want.

 

[BillK]

Just do a search on "motorized floor register" Plenty of choices. Here is one:

The Activent

The Activent Temperature Controlled Vent Register - Save money and energy by controling the temperature of individual rooms at the vent.

www.theactivent.com

 

[mike93lx]

From the OP's description I'm assuming he has no desire to control any of the equipment in the houses .... just trying to modulate (down) what is now coming to the room with the larger duct.

That's exactly it. If I was putting a new system in, I might look at zoning off the room, but it is very small compared to the rest of the first floor (100 sq ft vs about 1500), so I don't know how well that would work.

This isn't enough of a problem to justify a separate system, like a 9k mini split.

I just need to regulate incoming air flow

 

[mike93lx]

Just do a search on "motorized floor register" Plenty of choices. Here is one:

The Activent

The Activent Temperature Controlled Vent Register - Save money and energy by controling the temperature of individual rooms at the vent.

www.theactivent.com

That might be worth a try considering how simple it is. Not having to cut into the duct would be great. Thanks

 

[danski0224]

The concept of a motorized damper and a thermostat would work, not sure on how well it would work in execution.

There are also manual cable operated damper controls, Young Regulator is one. The damper mechanism needs to be good quality though, not cheapo typical residential stuff. An opposed blade damper is the preferred choice.

The manual setup may be more reliable over time if the airflow can be tailored with minimal fussing.

 

[mike93lx]

The concept of a motorized damper and a thermostat would work, not sure on how well it would work in execution.

There are also manual cable operated damper controls, Young Regulator is one. The damper mechanism needs to be good quality though, not cheapo typical residential stuff. An opposed blade damper is the preferred choice.

The manual setup may be more reliable over time if the airflow can be tailored with minimal fussing.

i definitely do not want a manually operated solution...i have one already, its the box for my ptouch label printer. i slide it over the register when it's too hot, remove it in the morning when the room is too cold since i forgot to do it at the end of the day.

i just went in there. with the door closed, and nothing over the register, the room was 84 degrees, while the room immediately adjacent is 70. if i fully block the register and leave it overnight, the room will be around 5-7 degrees cooler than the adjacent room

 

[danski0224]

If the room was otherwise ok in winter, the manual damper throttling will work just fine.

It will also allow fine tuning (set and forget), then open up the damper in summer.

Not as glitzy, but it would work if the room conditions were acceptable in winter before.

 

[mike93lx]

If the room was otherwise ok in winter, the manual damper throttling will work just fine.

It will also allow fine tuning (set and forget), then open up the damper in summer.

Not as glitzy, but it would work if the room conditions were acceptable in winter before.

this is my first winter in the house.

 

[csi123]

I am not familiar with your local code but are you sure you don't already have a damper in your ductwork already? Uneven heat distribution is extremely common so that is why usually there is one damper in each register branch. If you lift up the floor register you should be able to see it. Just close it partially to limit the airflow in the winter and open it fully in the summer.

 

[mike93lx]

I am not familiar with your local code but are you sure you don't already have a damper in your ductwork already? Uneven heat distribution is extremely common so that is why usually there is one damper in each register branch. If you lift up the floor register you should be able to see it. Just close it partially to limit the airflow in the winter and open it fully in the summer.

The register has a damper but there is definitely not an additional one in the duct to that room

 

[BetterDays]

The register has a damper but there is definitely not an additional one in the duct to that room

Do you have easy access to the duct to add one?

 

[mike93lx]

Do you have easy access to the duct to add one?

Yes, it's all in the encapsulated crawl. I have zero interest in a manual damper though. Anything I put in would need to be thermostatically controlled. Wireless would be nice