Ideas for how to fix uneven home heating/cooling?

Thread title should really be Ideas how to FIX etc

All HVAC and such is all new as of last summer when I purchased I the house (it had been completely remodeled due to smoke damage). 

The issue is, the house is on a corner lot and is sort of shaped like boomerang, but with hard angles not soft ones. All the utilities, (HVAC/water heater) are on the far NE side of the house in the garage. It's a 3bed, 2 bath, 2 car garage home. The 2 smaller bedrooms and 2nd bathroom are in the other "wing" of the house. The problem is though two rooms see a HUGE temperature difference in winter and summer. 

For example, right now we've been leaving the thermostat set to keep the house heated to 71 degrees during the day, this keeps the living/dining/kitchen/master bedroom and bath (which are all open to each other inbetween the two "wings") nice and comfy. The two smaller bedrooms are probably in the 58-60° range. And of course it's the opposite in the summer, if we have it set to 70° in the summer, those two rooms will hover in the upper 70s near 80. Which makes it uncomfortable since I work from home 2-3 days per week, and my girlfriend works from home full-time..............and we use those bedrooms as our offices.

There is a return in the hallway that connects the 2 bedrooms and baths, all the vents that blow air in to the house are in the slab on the outside walls, both returns are in the ceilings toward the middle of the house. Even with closing or severely restricting many of the vents, it doesn't help much on that end of the house.

Are there any options to try and help get more of the airflow down to the opposite side of the house? 

Zoning setups with dampers in the ductwork.

Sends the air where it's needed when it's needed.

Since you've already tried to balance the system by closing the vents near the furnace and opening the far vents, you're left with not enough air flow.

Some furnaces unit are multi speed. It would just be low/med/hi at best but it's something to investigate.

Grizz's suggestion could work here too.

Grizz said:

Zoning setups with dampers in the ductwork.

Sends the air where it's needed when it's needed.

Any more explanation? That sounds expensive, the house is only ~1815 sq ft. I'm sure it's exacerbated by the fact the dining area has a 11-12' cathedral ceiling and the living room and master bedroom have 16-17' vaulted ceilings. 

My boss at work suggested something like this:

https://www.homedepot.com/p/Suncourt-Flush-Fit-Register-Booster-Fan-in-White-HC500-W/202803685?cm_mmc=Shopping%7CG%7CBase%7CD29A%7CMulti%7CNA%7CPLA%7CMajor-Appliances%7CSpecial-Buys%7c71700000032418849%7c58700003842365800%7c92700030987191770&gclid=CjwKCAiAz7TfBRAKEiwAz8fKOLE3Z4jwZTsVX8P1O4c1BKJ2VZVYjkWFbEzDEYyvJEn4WZ9Z_2KVyxoC87gQAvD_BwE&gclsrc=aw.ds


To help get more airflow to the other side of the house, has anyone tried one?

In reply to z31maniac :

 Shameless hotlink that makes it easier to explain.

I've only ever installed one or two but it's the same as installing normal dampers in the ductwork only there's a board that adjusts them automatically instead of having to do it yourself. Although I think the ones I did were air actuated instead of electric.


As far as price goes I couldn't tell you because that's different for each job and I'm just a monkey that hammers on sheet metal.

Yeah, that looks rather expensive since all vents blowing air into the house are in the slab.  Since we don't plan to stay in the house much past being able to sell and break even, I'm not sure that would be worth the investment. 

Although, I need to call my HVAC/Plumber/Electrical company out to the house soon for a couple of other things, so I'll see if I can get a quote, so I'm not just talking out my a$$

In reply to z31maniac : what about external factors?  Insulation and  window loss?  

Have you contacted your utility company?  Here they come out and do a thermal scan to see where you are losing heat/ A/C  it’s pretty cheap too, about $100 and the do an energy audit  showing which appliances use too much etc.  

The great thing about it is you know and have actual pictures in your hand.  They didn’t try to sell me anything else or insist something be fixed etc.  

Since making an HVAC system work is all about getting the proper circulation it sounds like your blower isn't moving the air out to the ends well enough.  Once I added a room to a house I owned and installed an inline "kicker" fan that just spliced into the 6" ductwork in the crawlspace and it did an amazing job keeping that room climate controlled.  Unfortunately your supply ducts are buried in concrete but the same rule should apply if you increase the air return from the far ends it would have to draw more from the furnace (auxiliary fan in the return plenum).

My house has a similar challenge and it leaves my bedroom pretty chilly in winter.  I just stick one of those oil filled electric radiators in there and let it go at that.

^I actually went to Lowe's the other day to buy an oil-filled, electric radiator.........all they had in the store were the stupid fake fireplace electric heaters. I don't need the "ambiance" in my office. 

But I'd like to not have to wear sweats, socks, a hoodie, and a beanie to work in my office when it's cold.

Frenchy, that's a good question on the insulation. I know there is insulation over the kitchen/laundry room/and our master bath. Obviously the bedroom/dining area/and living room don't have much because of the cathedral/vaulted ceilings. But that "wing" of the house, I'm not sure how much if any insulation is there, because there doesn't appear to be a way over there from the attic above the garage/bathroom, and there is no access point to any attic space that should be there.

z31maniac said:

Yeah, that looks rather expensive since all vents blowing air into the house are in the slab.  Since we don't plan to stay in the house much past being able to sell and break even, I'm not sure that would be worth the investment. 

Although, I need to call my HVAC/Plumber/Electrical company out to the house soon for a couple of other things, so I'll see if I can get a quote, so I'm not just talking out my a$$

Are there possibly individual room/area ducts going into the slab on the furnace end?

Who the hell thought burying the ductwork in concrete was a good idea is what I want to know.

Since you can’t access the supply ducts, you are limited. 

I would install ceiling fans in those high ceilings, pointed up. If the room is cozy now, you are actually over heating the high volume areas. Ceiling fans will push that heat back to floor level. 

2nd thing I would look into are exchange ducts with circulating fans in them. An exchange duct is used in commercial jobs to get return air from one space to another.  For example, an office that always has the door closed to a hallway. Basically,  they put a register in each room with ducting between with several elbows to limit sound transmission. If you added a circulating fan to this, you could move the warmer air into the cooler rooms. 

Also consider running a camera down those supply ducts. If they are in the slab, I’m sure they weren’t replaced with the renovations. Ducts in slabs are prone to deterioration and collapse. They could be constricted. 

In reply to Grizz :

It's not uncommon in slab on grade houses.

In reply to dculberson :

It’s not uncommon in old slab on grade houses. It’s rarely done now. 

Grizz said:

Who the hell thought burying the ductwork in concrete was a good idea is what I want to know.

It's very common to build homes on slabs in this part of the country. The water table tends to be very high making it difficult to keep the garages from being swamps (at least this is what I have always been told). 

But you'd think with the penchant for horrible weather in tornado alley where underground shelters are deemed necessary, they would have figured it out by now. 

dculberson said:

z31maniac said:

Yeah, that looks rather expensive since all vents blowing air into the house are in the slab.  Since we don't plan to stay in the house much past being able to sell and break even, I'm not sure that would be worth the investment. 

Although, I need to call my HVAC/Plumber/Electrical company out to the house soon for a couple of other things, so I'll see if I can get a quote, so I'm not just talking out my a$$

Are there possibly individual room/area ducts going into the slab on the furnace end?

I'm not familiar enough with HVAC design to know, or exactly understand the question. 

SVreX said:

In reply to dculberson :

It’s not uncommon in old slab on grade houses. It’s rarely done now. 

In this part of the country, 95%+ are slab homes since the late 60s or earlier. And they still are today, from $130k starter homes up to $400k custom homes in huge lot, gated communities. 

Right. But do they put ducts in the slab?

No I get that part.

But at the very least make a crawlspace or put it in the attic or something. How the hell are you even supposed to service the duct without it being a massive undertaking?

 

In the last 20 years of my building in the South, I have been in more than 500 houses. More than 80% of new houses in my area are on slabs. 

Not a single one had ducts in the slab. 

SVreX said:

Since you can’t access the supply ducts, you are limited. 

I would install ceiling fans in those high ceilings, pointed up. If the room is cozy now, you are actually over heating the high volume areas. Ceiling fans will push that heat back to floor level. 

2nd thing I would look into are exchange ducts with circulating fans in them. An exchange duct is used in commercial jobs to get return air from one space to another.  For example, an office that always has the door closed to a hallway. Basically,  they put a register in each room with ducting between with several elbows to limit sound transmission. If you added a circulating fan to this, you could move the warmer air into the cooler rooms. 

Also consider running a camera down those supply ducts. If they are in the slab, I’m sure they weren’t replaced with the renovations. Ducts in slabs are prone to deterioration and collapse. They could be constricted. 

Yeah, the rooms definitely aren't cozy now. 

I suspect calling someone out to run a camera down the vents to check for deterioration is the best bet. We did have a company come out recently to clean the air vents with the big vacuum/brush thing, but there doesn't seem to have been any noticeable change before/since. I just knew there was lots of crap/dust/construction stuff in there and wanted it out of the house. 

SVreX said:

In the last 20 years of my building in the South, I have been in more than 500 houses. More than 80% of new houses in my area are on slabs. 

Not a single one had ducts in the slab. 

Gotcha, I misunderstood. I thought you were saying they weren't building on slabs anymore, not that they don't put the vents in. 

You are correct, the new homes I've looked at, the returns and forced air vents are all in the ceiling. 

Ducts under a slab on grade are generally avoided because the risks of moisture intrusion are far too great to justify any advantages to such a system. They can end up with standing liquid water, pools of stagnant scum, thick mold, mildew, and thriving ecosystems. No way to fix it, either, once you realize you have a problem.

This is another reason running a camera down those ducts would be a really good idea. 

I’ve been in some commercial spaces that have ducts under the floor, but they are not encased in concrete or dirt. They are installed in tunnels that can be accessed later. 

Since you’re not going to be there long term, I’d look into window unit AC’s (which if it weren’t for the look is all I’d have anyways for a small house—and I say this only after our AC went out two summers ago and I ran to KMart and bought 2 for $250. It was 105 outside. And humid)

As for heat, my parents put in little heaters in the kickboards in the kitchen and bathrooms at their place. They kick on when the heat kicks on. Not sure how they’re wired up, but they are completely standalone electric heaters. These would make sense in the farthest spots from the thermostat.