I shut off my vents in the basement during the summer. Also make sure your basement door stays closed. Cooled air falls, warm air rises. Our last house we had a wall hung natural gas moore heater. It kept the basement toasty. My son has a electric fireplace in his. Also W/W carpet with padding insulates the cold from radiating up through the floor.

Electric baseboard heating would work. It does not take much heat to raise the temperature of a basement. It would not be as expensive to heat compared to an an above ground floor.

Try a dehumidifier in summer to take the damp out. As soon as we switch to A/C out comes the dehumidifier or you're wrapped in quilts - and that's with all the basement vents closed. W2W carpet & underpadding can also help for sure as suggested. Also, any chance there's a blockage in the venting for the basement run?

It's an open concept home, so there is no door to close to our basement.

Are there companies that sell and install electric baseboard heat? I've talked to a couple HVAC companies and they do not.

Is it bad for the HVAC system to close all the registers in the basement? Will the added static pressure in the system damage the ductwork or cause other HVAC components to work too hard / overheat (blower, heat exchanger...) or limit the life of our system?

Well contact the makers of electric baseboard heaters in your area they will have installers Your elecrical panel will need to be able to handle them but in a newer builds not much issue usually .You have ductwork in the basement ? How was that done if there was no plan for heating the basement. I would speak to the HVAC guys that did this to see if maybe they have an answer .

Yes, we have ductwork in the basment - just really unbalanced. We only have 4" ducts in bedrooms, without returns. We don't have any ductwork going to our 2 bathrooms in the basement.

We have to heat our upstairs to 80 degrees to get 68 degrees in the basement.

Look into a ductless mini-split system.

How many registers are in the basement and how many in the rest of the house? How large is the basement area you are trying to heat?

You can hire an electrician to install the baseboard heaters. I suggest the type that operates on 220V.. I also suggest installing a programmable thermostat. You could install a thermostat for each room if you want complete temperature control. The mini split would work but it will be much more expensive and you will only use it in the winter. It would distribute the heat as evenly as the electric baseboards.

How on earth does open concept have anything to do with not having a basement door?

"4" ducts in bedrooms, without returns." Who built this house and who did the HAVC?

"We don't have any ductwork going to our 2 bathrooms in the basement." Why not? Was the basement finished out as living space for bedrooms? A lot of things don't add up here, are there any walls in the basement at all?

I just meant the basement stairwell is open - there never was a door in the design, and it would be impossible to add one.

This is fairly high-end new construction, and they knew ahead of time that our basement would contain 1/2 of our bedrooms (2) and 1/2 of our bathrooms (2). We discussed the importance of our system with the builder and would have paid extra to get it to function properly. We even paid extra for a zone in our Master Bedroom to make sure we could keep it cool for sleeping in the summer.

We agree that a lot of things don't add up, and we are devastated after entrusting our builder with a large portion of our life savings!

We trusted our builder to make sure the HVAC system was designed properly...and that was clearly a mistake.

I attached the HVAC system design drawings in a previous post.

Here is the defective HVAC plan

We have 13 registers on the main and 7 registers in the basement. Most of the basement registers are only 4" ducts.

Our HVAC contractor wants to divide our house at the furnace and create 2 zones by adding a damper to each side of the air handler/furnace. One to the left side and one to the right side. We have a single stage system, and it seems wrong to send the full force/volume of air (designed for our entire house) into each side...especially the left side which is only about 1/3 of the home's volume with mostly small ducts that have complicated twists and turns in them.

It seems like the builder and the HVAC contractor know the system is a messed up / terrible design, and don't want to tear down drywall to fix it properly - if it can be fixed at all. They just want to do something to make us shut up and go away.

We don't want to have them do something that will damage our system or shorten the lifespan of our system.

Can all the extra pressure caused by dividing our single stage system like this damage our ducts (create leaks), blower, heat exchanger...

Hi, Max,

You've got a design problem which is no longer limited to the paper variety.

Basements typically have smaller heating and cooling loads than other living areas in a home. They need special design consideration which includes a ventilation strategy, too. If a basement is to be zoned off a single system conditioning the entire home, the system would need sufficient turndown capability to accurately control the temperature in the basement when other portions of the home aren't calling for heating or cooling. That's a tall order.

A system designed specifically for conditioning the basement is usually a better option, especially when there is as much finished living area as your home has in the basement. Because there is little, if any, cooling load (and thus little potential for dehumidification) I like to install a dedicated dehumidifier integrated into the basement's HVAC system. We're currently finishing up construction of a home with a ducted mini-split HVAC system the basement which has two-separate zones of control (there's an exercise room) and an integrated dehumidifier.

Your HVAC design should also consider ventilation of the basement living areas to ensure adequate fresh air. If you have the potential for radon or soil gases in your area, the ventilation system needs to consider them, too.

Zoning of your home's single system into left/right halves of your home will do little if anything to improve comfort in your basement. I suggest your builder and co. will need to go back to the drawing board (or its electronic equivalent.)

I see you have a Lennox Merit series 45K BTU furnace. This is a new build. Did the HVAC installer do a load calculation and do you have a copy of it? If you have a copy you can post it for comments. If no load calculation was done, then that might explain why you are having problems. There should also be a calculation for duct sizing. Ask the builder for a copy of the Manual J (heating/cooling) and Manual D (duct sizing) calculations. The drawing you posted says unfinished bonus room. If they are unfinished then adding additional duct work and registers should not be too difficult.

Adding dampers and closing off half the duct work if a bad idea. It will increase noise and static pressure. It creates more wear and tear on the blower.

What I see is a mess of incorrect duct configurations in the ceiling of Bedroom # 2, like it was an after thought on how to heat the basement.

3 take offs from the end of a 4x10 main duct? what were they thinking, and is there at least a 24" tail on the end of the 10" main, and at least 12" distance between take off's to build total pressure? Who knows.

Using a branch duct to feed other branch ducts jut doesn't work good.

1. A 7" take off from the main and split to a 6" to feed an upstairs resister and a 4" branch to bedroom # 3. Does this 4" duct even have any air blowing out of it. Not much IMO.

2. A 6" take off split into two 4" branch ducts for the bath and bedroom Number 2.

And with no returns pressurizing the bedrooms I'd say most of the Air flow takes the path of least resistance and it's sure not going into the bedrooms.

Don't let the builder and HVAC contractor walk away from this, it's a mess. The duct work in this entire area needs corrected and it if means tearing out ceiling sheet rock let it happen. David Martin is also at fault if he didn't design the joist/truss space for the correct ducting. Good luck, and get a door installed to the basement.

Yes we know we have been screwed!

The ductwork is a jumbled up mess.

Not only that, they had to do a lot of rerouting after the plans I posted were created. No documentation was created to show what they actually ended up doing.

Their first attempt would have required the ceiling in the front basement bedroom to be dropped below the height of the window - celar evidence of ZERO THOUGHT, ZERO CARE!

They had to move the main trunk/plenum to the front wall of that bedroom, so there would be a bulkhead that did not interfere with the window.

As a result, the main trunk/plenum has TWO 90 DEGREE turns in close proximity to the air handler. This obviously creates a lot of turbulence and inefficiency.

So, add that to all the twists and turns and splits in the ducts on the left side of the house...it's truly heartbreaking!

I have two HVAC contractors (not the company that installed this mess) coming out tomorrow to see what potential fixes they propose.

We are open to anything at this point. Tearing out drywall to re-route / resize ducts, ductless systems, baseboard heaters, swapping out for a variable speed system - trying to create zones or even a separate system for the basement...

If anyone has any other input, advice, or questions I should ask the HVAC contractors, please post.

@mike_home 45K/2ton sitting in the attic supplying the attic bonus room, 90K/3.5ton sitting in the basement supplying the 1st/basement.

@Mike_home: Our system was actually swapped out for a CARRIER Model 59SC2D Single Stage Multipoise Condensing Gas Furnace.

It was swapped out due to supply chain issues getting a compatible AC unit to the Lennox model.

Is this even a comparable model? Maybe this has something to do with our problems.

I really appreciate your advice / input

So you have only one 100Kbtu/4ton furnace/coil for the whole house (1st, 2nd, basement)?

We also have a system for our ~ 600 sqft bonus room over our garage which they branched off and zoned (with a variable speed system) to heat and cool our 16'x16' Master Bedroom on the main floor - STRANGE isn't it???

Keep in mind, this is new construction, so these yahoos could have designed anything. It was a clean slate!

It's a ranch with a bonus room over the garage.

The main floor square footage is just under 2500.

The basement is completely finished except for a small mechanical room.

We have a 600 sqft. Bonus Room over the garage which has it's own 2 ton variable speed system, which I just posted model/serial numbers. It is zoned to heat and cool our 16'x16' Master Bedroom on the main floor since we negotiated a zone in our contract using dampers and ductwork through our unconditioned attic space.

The HVAC contractor said it would be impossible to zone our Master Bedroom and Basement off the main system, but I think they just didn't want to or care to.

This is an always for full basements. My daughter's room had a ceiling height electric heater so her room was always fine. We also have a pellet/corn stove that keeps it toasty. Other than each room it's own zone there is not much that can be done.

We do have 10' and 12' (Great Room and Dining Room) ceilings on the main floor. We have 9' ceilings in the basement, and 8' ceilings in the Bonus Room

What is the flooring in your basement? You might want to consider ditching the unhelpful HVAC people and trying under carpet heating.

https://www.warmlyyours.com/en-US/floor-heating/carpet

We have thick rubber flooring in our gym, tile in our bathrooms, and and LVP type product with a real wood veneer on it. it is a click together rubber backed product. We laid down a 3mm foam underlayment beneath the flooring.

Does anyone know if BAGI standards for HVAC apply to finished basements? The BAGI standard says something like +/- 3 degrees when measured from the center of a room at 5' high.

We're in central Indiana if you want climate information.

The BAGI standards are a set of voluntary quality assurance standards available to members of the Builders Association of Greater Indianapolis.

The National Association of Home Builders publishes Residential Performance Guidelines for Professional Builders and Remodelers which is a nationally-recognized quality standard. The NAHB Performance Guidelines require heating systems to be capable of maintaining 70 F measured in the center of a room 5 ft above the floor under local design conditions and cooling systems to maintain a temperature of 78F in the center of a room measured 5 ft above the floor under local design conditions.

I’m so sorry this is going on for you, maxjackjoe! We purchased a home built in 2017 (so not that old) and the HVAC system was woefully undersized as well (I’ve since heard several other neighbors complain about the same issue) - we had a new furnace/AC unit put in - and because my workshop is in the basement, we put two additional ducts in (yep, tons of drywall torn up) as well as a new gas fireplace, another return as well. Costly, but at least I can work in my shop without freezing. Be prepared for a huge mess :(

We may have just discovered something else odd about our system.

We have two PVC pipes coming out of our furnace. One is the flue pipe which I understand expels combustion gases through the roof - like a chimney. The other is a fresh air intake.

Our fresh air intake is only about 1 foot off of our furnace - drawing “fresh air” from our small mechanical room. Should the fresh air intake pipe also be routed outside our house to get fresh air from outside?

What problems could we have due to the fresh air intake drawing air from inside our mechanical room?

We appreciate advice from those who have experience with this

Your Furnace have been identified as a condensing unit and should have two 2" PVC pipes coming out of it. The exhaust should without question be terminated outside. The other for fresh air Should be also terminated outside if the mechanical room is determined to be a confined space, and it is. This is odd but to avoid any confusion a few pictures would help clarify any uncertainty.

It could be a problem if there is a gas hot water heater in the mechanical room. Having the furnace air intake could cause back drafting from the hot water heater flue. Keep the door of the mechanical room open when the furnace is in use.

Did you hire an attorney to do your closing? If not then think about having a consultation with a real estate attorney. You have serious problems which is going to take a significant amount of time and money to fix. Read your contract to determine how problems are resolved. Document everything that has occurred. Your builder did not hire good contractors. I would not be surprised if you find other problems.

UGH - We were trying to avoid lawyers, but it's been 7 months and the builder has not acted in good faith to fix all the problems. In fact, they have been working against us with their vendors in most circumstances.

Attached is a picture of our furnace, flue pipe, fresh air pipe, and gas water heater. Why would this set up not raise red flags with the inspector?

We have had 2 gas leaks in this little room (11'x14') as well as a flue pipe leak.

Maybe this explains why I have had unusal bouts of vomiting and diarrhea. I've had what I thought were 3 food poisening incidents since we've moved into this house.

The gas hot water seems to have a power vent. I will defer to the hot water heater experts to determine if this arrangement is cause of concern for back drafting.

It is hard to tell from the photo, but is the gas line feeding the furnace and hot water heater 1/2 inch in diameter. That would seem undersized for a 100K BTU furnace and a 40K or 50K BTU hot water heater. Maybe the original intention was to install the 45K furnace but when it was changed to a 100K no one considered the size of the gas supply line.

I agree using a lawyer is the last resort. The builder may be trying to run out the clock on the one year warranty. You have consider it if he has nothing for 7 months and you have health concerns.

Are they any inspection stickers or records that indicate an code official approved anything?

Per your house plans the mechanical room is a confined space and the furnace fresh air intake should be ran to the outside of the house, or 2 big air makeup openings should be in the walls from the outside. Do you see any big Vents or ducts going directly to the outside?

Mike is right about the back drafting and potential safety issue. He's Also right if the gas line 1/2" but to me it looks like 3/4".

The plans don't indicate any doors installed at the mechanical room. Irrespective of whether doors are installed, I don't think it would meet the definition of a "confined space." We don't know if any outdoor air is being supplied to the mechanical room nor do we know whether the volume of the space meets the combustion/ventilation/dilution air requirement assuming the applicable code is 2018 IRC G2407. The appliance manufacturer's installation instructions may govern.

The power-vented hot water heater is not a back draft risk, but it does require an adequate supply of combustion air.

There is definitely a door on the mechanical room.

There are also two small vents from the mechanical room to the basement rec room (not to outside). one is low on the wall and one his high.

it looks like it is designed to draw air from the basement rec room through those small vents into the fresh air intake.

i don’t see any vents going outside,

Your furnace is using room air--which you've paid to condition-- for combustion air. While it's allowed by code, it's not preferable to supplying outdoor air directly to your furnace.

Does this reduce indoor air quality? Since were not using ”fresh” air?

The amount of air used for combustion needs to be supplied from somewhere. When indoor air is used for combustion air, that air would be replaced either by air leakage in your home's shell or by a make-up air system designed for that purpose. In the winter, infiltration of outdoor air would tend to decrease the indoor relative humidity.