How to fix uneven heating / cooling in house?

[samclem]

Wouldn't the easier solution to sealing the ducts be some mastic at the duct joints? I have heard of the gas but have not heard any reviews, Let us know how it does.

If the ductwork is accessible, I'd sure give this a shot. A tub of mastic and some fiberglass mesh reinforcing tape will seal a lot of leaks, and they will stay sealed. If the ducts are flex duct, then some plastic clamps (giant zip ties) and a tool for tightening them will be needed.

I put a couple of $100 window AC units in the bedrooms to do essentially the same as skipro, and it works like a champ. The rest of the house doesn’t need to be cooled at night, so we actually have reduced the electric bill over the past couple of years by doing this.

This can work great. Some people find that these units are too noisy for them, but they aren't as noisy as they used to be. In most parts of the country they need to be put in/taken out each year, which is a chore but really doesn't take long. Even modesty-priced window units can come with remote controls, and if they have their own thermostat then it can be placed right at the bed and not be subject to the external temps at the window unit itself--perfect. Together with programmable setback thermostat in the house (to let the rest of the house get warmer at night) they really do save energy.

Obviously, one thing to check before spending any money is the ductwork. The OP's house is new, which means it almost certainly has extensive runs of flex duct ("slinky duct"). Builder's love this stuff because they can put it in quickly and save a lot of money. Unfortunately, it is easy to do a really crummy installation job, and that's exactly what gets done a >lot< of the time. The straight lengths of the ductwork should be fully extended (if isn't, the rumpled interior of the duct drives up the resistance to flow a lot, and rooms served by that duct may not get enough hot/cold air). The straight lengths should be supported frequently, even a modest sag (common) can double the resistance to flow compared to a smooth metal duct. Also, make sure it isn't crushed or kinked (very common, especially where it hangs from supports and where it connects to something else). Ideally, the flex duct itself shouldn't be bent sharply to make a turn, it is better to use a regular metal elbow to make such turns and get things lined up so that the flex duct can be connected straight on to another fitting. Also, see that everything is securely connected and feel for hot/cold air leaks.

Regarding leaving the doors open: This can help keep the temps in the house a little closer to uniform if the equipment isn't running, but it shouldn't be necessary when the fan is running >if< each room has sufficient return air capacity. In more "deluxe" systems this will be via a separate grill in the room. In most run-of-the-mill moderately priced homes, the return air just leaves the room under the door. This can work okay, but the door has to be cut significantly higher than the flooring (generally more than an inch, sometimes much more). If a home originally had wood floors and carpet was later installed without re-cutting the doors higher, then there can be a problem.

 

[Which Roger]

I've had a similar problem for many years. Thermostat is on the north side of the main floor, i.e., the coolest part of the house. I'm replacing the AC and furnace soon and will get some sort of portable thermostat(s) so I can control the temp from anywhere in the house.

 

[samclem]

The fan should have remote, and a reverse setting. Push air down in summer, lift air in winter.

When a ceiling fan is "pushing air down" (directly beneath the fan), it is also "lifting' exactly the same volume of cool air from the floor to the ceiling (at the walls). Reversing the fan won't have any impact on the stratification of the room air temps, but maybe the more direct, higher velocity air stream of downward flow directly under the fan feels better in the summer (convection and evaporative cooling of the skin).

 

[harley]

Wouldn't the easier solution to sealing the ducts be some mastic at the duct joints? I have heard of the gas but have not heard any reviews, Let us know how it does

We tested our vents in our old home. 50% leakage! No wonder I was in a hoodie all the time. We did an energy audit as well. Helped tremendously to improve comfort

Most of the ductwork isn't accessible. It's a townhouse and the ductwork is mostly behind walls and ceilings. Otherwise you'd be spot on.

 

[W2R]

You all are so inventive!!!

Here's what I would do.

1.) Look at my portfolio balance after NINE (9!) years of bull market.

2.) Call my HVAC guy, explain the problem, and listen to his suggested course of action.

3.) Tell him to go ahead and do it. Pay him what it costs after he is done.

That's it! "The W2R Solution" to this dilemma.

 

[badatmath]

Proper HVAC guys can calculate what needs doing. I plan to get one of the ducts rerouted when I replace ac (soonish). Two of them suggested adding returns to other rooms as well. But I would get them to take a look if you can't solve it thru trial and error as above.

 

[samclem]

You all are so inventive!!!

Here's what I would do.

1.) Look at my portfolio balance after NINE (9!) years of bull market.

2.) Call my HVAC guy, explain the problem, and listen to his suggested course of action.

3.) Tell him to go ahead and do it. Pay him what it costs after he is done.

That's it! "The W2R Solution" to this dilemma.

Oh, sure, there's THAT approach. Problems:

1) HVAC guys are a little like FAs: It's hard to know if they are competent unless you know a little about what they are supposed to do. Yelp, Angie's List, BBB etc reviews often don't address the issues here ("The technician was very nice," "they showed up on time." etc) Like some of the folks in this thread, I have had a very hard time getting one to run a Manual J calculation to figure out what size equipment is needed, they'd prefer to use an inaccurate rule of thumb and just make sure it is oversized. A situation like the one described in the OP is ripe for a solution that is a huge ripoff.

2) This way is way more fun.
3) Your approach only works during a "Weee!" After the "Weeh!" and the resultant crash, we're back to sticking the box fan in the window until Mr Market gets happy again.

 

[W2R]

Oh, sure, there's THAT approach. Problems:

1) HVAC guys are a little like FAs: It's hard to know if they are competent unless you know a little about what they are supposed to do.

Well, I have a good HVAC man. He did a great job with my new HVAC system and didn't overcharge me. I have no idea why anyone would rely on Angie's list or BBB reviews when they live in a community where everyone knows who is good and who isn't.

Maybe New Orleans is more of a "small town" than some. I admit that families tend to live here for hundreds of years, so everyone pretty much knows everyone and their family and who is good vs who is an out-of-towner that will overcharge and doesn't know what he is doing.

Yelp, Angie's List, BBB etc reviews often don't address the issues here ("The technician was very nice," "they showed up on time." etc) Like some of the folks in this thread, I have had a very hard time getting one to run a Manual J calculation to figure out what size equipment is needed, they'd prefer to use an inaccurate rule of thumb and just make sure it is oversized.

You have GOT to be kidding. No, I know you are not, but yikes. Every housewife around here knows about Manual J calculations, and also knows that oversized HVAC equipment is almost as bad as undersized. It sounds like the HVAC guys in your community are incompetent part timers working their way through [-]college[/-] high school. I cannot imagine paying someone like that a dime.

2) This way is way more fun.

Bingo! I think that this, rather than getting the best results for the least money, is the motivation behind many of the home repairs that self avowed millionaires describe and discuss on our forum.

3) Your approach only works during a "Weee!" After the "Weeh!" and the resultant crash, we're back to sticking the box fan in the window until Mr Market gets happy again.

Well yeah, but right now when I look at my portfolio balance I am inclined to spend it on things that make my life easier and more worry free both now and later on when the market does crash. For me, this is one of them. YMMV!

 

[samclem]

New Orleans, Houston, etc: AC is a big deal. And even the best AC equipment doesn't usually live for decades there, so there's plenty of AC service and installation activity going on, and it's something people talk about. AC equipment in much of the country can last for decades (mine is 23 years old now), and furnaces, by their nature, are generally less trouble-prone than AC.

I have no idea why anyone would rely on Angie's list or BBB reviews when they live in a community where everyone knows who is good and who isn't.

Maybe New Orleans is more of a "small town" than some. I admit that families tend to live here for hundreds of years, so everyone pretty much knows everyone and their family and who is good vs who is an out-of-towner that will overcharge and doesn't know what he is doing.

It sounds like you are better connected to your neighbors than I am, maybe better than most people. We waive to each other, but I do not know them. Even if I got into a discussion with Mr Smith next door said he had a good HVAC guy, I'd have no way of knowing if Mr Smith got ripped off and doesn't know it (again--we all have seen instances of people in love with their FA or broker, blissfully unaware of the fees they are being charged or the inappropriate investments their money is in.) If Mr Smith called the contractor, paid the money, and now his AC works, he may not know if he paid a reasonable price or even if he got the best solution.

The big HVAC contractors have technicians that span the spectrum in competence. If I call and say my furnace or AC has crumped, they will send a "comfort consultant" who may or may not know how to troubleshoot things--he/she is there to sell me equipment. They have other "installers" who know how to swap out equipment, but they don't do duct design and aren't competent to troubleshoot problems. Maybe they passed a test some time ago, but they are paid to get equipment installed.

If I got a word-of-mouth recommendation from someone who knows what they are talking about for a one-or-two person HVAC service company, it would mean a LOT.