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.

I have essentially the same issue. I did check the Manual J heat loss for our front bedroom (which can be colder) and found what I suspected; the heat loss is much larger than the other spare bedroom. I suspected this because of 3 outside walls and a lot of windows. The insulation values of the walls in the concrete block houses is only R-5. I find this a surprisingly low value. The insulation value of the windows is also low (typical unless you go with triple pane). The aluminum frames on the windows doesn't help as they conduct heat. I noticed the new homes have vinyl windows. The best insulation is in the ceiling at R-30. Apparently these insulation values are to code.

I don't think anyone is really to blame. These are not custom built homes where you can design your own systems. It is just not possible to maintain uniform temperatures with a single zone system under these conditions with relatively short heatpump run times. During the summer, temperatures are much more uniform but there are also longer heatpump run times. Unless you can find something in the building code about a required maximum temperature variation across the house I believe we are out of luck. I am not happy about it but it is only an issue on a handful of days. I can fix it but it won't be inexpensive. A small portable electric heater with a thermostat is probably the lowest cost solution.

A Duraflame small heater that looks like an old fireplace does well in cooler areas, and surprising how much heat (has a flame and blower) it can give. It has been cheap to operate, safe, durable, and lightweight to move. Lowe's has them

Solved my cold room and need for an entertainment center problems with a Dimplex electric firebox console. Looks good and provides the right amount of heat. Got it at Babette's.

http://uploads.tapatalk-cdn.com/2016...99e6035c57.jpg

No wonder it's cold in there...you have "Ice Age" playing....!

Frank

We have a Designer home built in 2013 and the problem exists in our front BR and the same is true with our neighbors. We complained under warranty but nothing was done.
There are several problems:
Distance from the HP unit
Return is in the ceiling very close to the supply vent. Hot air rises so it stays up high
and it gets sucked out before it can heat the room.
Vaulted ceiling probably has far less insulation. Who knows if there is any insulation?

The Fix:
You could try closing off the return vent which will help keep more heat in the room.
What we did is put a small quartz heater in the room. It heats up real quick. Our heater
is wood and tall with a very small food print. It looks very nice and can be moved into
another room is needed.