Not the best solution. This will over cool in the summer and overheat in the winter.

Cold front bedroom
 

More info on this at post #12 and yes, all 3 bedrooms have both a supply as well as a return vent. There is also a large return vent in the main (dining) area away from the supply vents in the living room. Remember, the problem is not receiving enough heat in that room as it will warm up nicely. It just cools down too much between heating cycles, resulting in a cold room. Air conditioning is fine in that room.

Thank you everyone for the input.
I was simply wondering how extensive the cold room problem was and am finding it's more extensive than I thought. Also received some potential partial workarounds here, but the bonus is I've now learned what the actual fix seems to be. Tuccillo is right, a second zone according to a different, large local HVAC company.

Warranty department denies there's any problem at all saying the house was built and engineered according to all building codes and permits were issued by the county. There's nothing more that they will do.

I know. I guess you didn't read the last sentence in my post. I think your statement is incorrect. Balanced is balanced. It's true that the unit may run longer but that is because air is being diverted away from the thermostat.

At the risk of boring people to tears, here is how this stuff actually works. It starts with a so-called "Manual J" calculation. This is essentially a heat gain/heat loss calculation for the house that takes into account the dimensions of the home, location and number of windows, the insulating factor for the window, whether the windows have coverings, the orientation of the house (north, south, east,or west), the insulation of the walls, the insulation of the ceiling, the number and insulation of the doors, etc., the climate temperatures and humidity in the summer and winter, and your summer and winter temperature setpoints. From these calculations, you obtain the heat gain (in the summer) and heat loss (in the winter) for each room in the house in BTUs. The total for the house will size the HVAC equipment in terms of tons (12K BTUs is a ton). From this information you can then determine the number of CFM (cubic feet per minute) of airflow needed in each room to maintain the desired setpoints. A so-called "Manual D" calculation is then done to design the duct work to deliver the needed CFM.

By code, this is all done and what they told you is correct about the engineering work and permits. And it is probably correct for the house on average. But, without zoning you are still going to have some issues with temperature uniformity as a centrally located thermostat cannot react to rooms on the periphery that lose heat/gain heat faster than the main living areas.

In my previous house, I did the Manual J calculation myself, designed the 4 zones, and selected the equipment. I hired a local HVAC contractor to do the Manual D and the installation. The results were very good in that there was complete uniformity of temperature and outstanding humidity control because of a variable speed handler. The typical designer home should have 3 zones, in my opinion: the guest bedrooms, the main living area, and the master suite. In the premier homes, they do a little better with 2 zones. Part of that is probably necessary because residential equipment is generally limited to 5 tons and if the Manual J calls for more than that you have to have multiple systems.

Cold front bedroom?
 

...

A portable electric baseboard heater in that bedroom will solve the cooler (winter) problem. Set the temp on it to slightly less than what your house thermostat setting. It will only operate when the temp in that room gets below the setting in the main part of the house and will shut off when the furnace runs and catches up with the desired temp. Much cheaper than having professionals rework the system.

Have you checked to see if there is any/sufficient blown insulation in the attic over that bedroom? In one of my houses, I had one room that the builder failed to insulate in the attic.

Cold front bedroom
 

Yes, thank you. That's one of the first things they looked at and they blew in more just in case. I also had Frank D'Angelo the home inspector pay particular attention to that room using his infrared camera when he did the warranty inspection.

Everyone on my side of the street has the same complaint about their front bedrooms. We face north, and room gets light but no sun. We're also complaining about all this rain and our gardens turning to mush, but that's another problem.

SteveO,
Back up North, we had a cold room, and as noted above single zone heating system. One of the fixes I found that actually worked was to use insulating paint. The link below is for a ceramic additive that is added to any paint that makes it insulating.

Insulating Paint Additive Makes Paint Insulate

Please do your own research, but we had good success with the product. Also, this may be the lowest cost option, after a small space heater, but this has no monthly cost, and it is do it yourself.

NOTE: VERY IMPORTANT. Since you are adding the insulating material to the paint, YOU WILL HAVE A DIFFERENT FINISH TO THE NEW PAINT. It will be a rougher finish. I actually have some of this material left over, so if you would like to paint a small area to see the difference, send me a PM.

I have a six month old cottage home and it has return and supply vents in all three bedrooms and in the living, dining, kitchen area.

This is a well known and common problem. Tuccillo is quite correct, as well as others. While the current set up is most likely compliant to the Manual J for the home, variables exist.

There is only so much you can do without encountering significant costs. Of course, redesigning the system and adding zones would work, but that is quite costly...especially when you have a new home with a already new system.

Other methods, while less than perfect can also help. Balancing your system by adjusting vents MAY help to an extent, and it costs nothing. Making sure that duct is sized correctly for the room is also a good idea. Also insuring there are no "bellies" or excessive elbowing in the supply duct is also helpful.

Adding insulation there may also help, but understand that in most of these front corner guest bedrooms this area can be difficult to almost impossible to get to or even see. This is why I use a thermal imaging camera.

Personally I think the issue of cooling this room in the summer is more difficult than heating it in the winter, but that is just my opinion. Because windows are always less efficient, how you deal with that window can be a large factor.

Also, personal preferences came into play here. Many folks LIKE a somewhat cooler bedroom. However, if your home faces South or West in the summer and you do not deal with that sometimes huge window, good luck on keeping that room cooler in the summer.

You basically have the situation of three outside walls and a large window in a small square foot room.

I'm told that The Villages policy is that a 5 degree difference between rooms is acceptable. I have seen many times when the difference can exceed that.

Every home is different. Some folks never use this room. Some folks use this room for a craft room or office, and do not sleep there. Some folks use this room only a few times a year for guests, and do not want it to be TOO comfortable, because one typically does not want guests to overstay their welcome. (a bit of humor).

It comes down to how big this problem is perceived by the homeowner and how much they want to spend to make it less of a problem. If the home is under warranty, sometimes the A/C company will come out and adjust ductwork or enlarge it, etc...but there is only so much they can easily do.

Different window treatments can help in some cases, and some folks tint that window or windows, but be careful on voiding the window warranty if you do.

Basically, common actions to make this better is window treatments, adding insulation, upsizing the supply duct, adjusting A/C grills to balance the system somewhat, keeping the door open, using a small heater, etc, etc may help.

Villagetinker, I smiled when I read about your ceramic paint additive. I bought and used this product on the home I built up north, and I too have some of it left While I was not sure how well it worked, I got it for a good price years ago and thought I would try it. I never knew anyone else who had it until now.

I apologize for the long post. Since I was mentioned in an earlier post, I felt compelled to share.

Frank

Frank,
I actually gave some of this to friends up North, with a cold attic wall, that seemed to have a continual mold problem. After painting with the ceramic additive, they claimed the problem was gone! I used it in one room and did notice an improvement, but not as dramatic as their experience.

OP,
It occurred to me that you might be able to solve the problem with additional air movement. I would try a fan above the doorway to move warm air from the house to the cold room. This would require cutting into the wall, installing grates, and wiring for a fan. Before going to all of that work, you may be able to get some inexpensive fan(s) had do a temporary install in the doorway to see if it helps. Theory is that you would be adding warm air (near the ceiling), and removing cold air (near the floor).
Other then additional insulation I have no other ideas.
Hope this helps.

Probably has to do with amount of air supply, insulation and distance from the heat source. The air supply lines are fairly small to the smaller bedrooms and usually quite a distance from the heat source. The air supply lines are also transit the coldest part of the attic if the bedroom is on the North side.

Cold Front Bedroom
 

I'm the OP and very much appreciate the feedback and ideas.

Please keep in mind that the room warms up fine from the heat pump. The problem is that it cools too much/too quickly between heating cycles. Could be an hour or several hours between cycles. The rest of the house is fine but when you walk into that one room, it's cold.

Data loggers were placed in the house to monitor for a couple of days and is easy to see what's going on in that room compared to the main living area.
Early on, the main feeder trunk in attic was enlarged to that area and registers adjusted to maximize air flow into that room. Insulation was checked and increased. Fans operated, door open/closed. Air flow re-balanced. Nothing really changed. No trouble with the A/C during the summer, just cold during cool or cold days.

I have been asked by the builder and I think that the cause is either cold air infiltration into the ducts in the cold attic which then slowly drops into the room below via the vent, (remember warm air rises and cold air drops), or air leakage from those big windows or a combination of the two. No air leakage testing has been performed.

Over the past two years many of the ideas suggested above have been tried (have to look into the paint idea) This has been a continuing warranty item since day one. Warranty department will do no more to find out why. Let alone who pays for the fix.

It looks like I'll have to have a permanent supplemental heater installed as some have suggested. Not the end of the world, but I really shouldn't have to.

To those who have seen the heating and cooling engineering that goes into each individual house, you have to wonder how this could happen. If you haven't, you can look up your address here. The "MAND" and "MANJ" are the calculations that Tuccillo was talking about earlier.

https://etrakit.sumtercountyfl.gov/e...ch/permit.aspx

Permit Search> Site Address> Contains> (your address)

Click the "Attachments" at the bottom of the first tab.