We have a second floor bedroom with a vaulted ceiling (guessing 12 feet at highest) with ceiling vents. The heating is okay in there, but that room is a sauna in the summer. You would think cold air sinks and it would be fine, but it's not. IDK if the air gets too warm on it's trip from the HVAC equipment in the basement and through the walls and ceiling or what, but that is definitely something I would like to change about our house. So consider cooling as well as heating. Hopefully your HVAC person has some options for you.

French old world...stone floors?

Why does radiant heat not work well on hickory floors and is best on oak?

I dont know why but was told by my GC and two flooring people it is not a good option as the wood would get ruined.

Thanks, the vault goes to 22 in the center area then each side drops to 10. No stone, we definitely want wood!

They plan on putting the vents on the 10 ft ceiling space on each side of the vault. Essentially it vaults then then it drops to 10 ft for a flat ceiling on each side. Think that will be suitable or do I need to make a way to get radiant heating too?

I have never lived with nor installed floor heat but everyone I've talked to that has floor heat love's it. I can't comment on flooring because again I haven't dealt with it. I can't help but wonder why builder feel's you need"insurance". From years of experience I can tell you that balancing airflow require's education,research and dedication that too few are willing to undertake. When confronted with an unusual install that I was unsure of,I always paid a ventilation engineer to draw it up. Money spent up front can save 10 fold the amount if system has to be retrofitted later on. Not to mention the comfort and aggravation elements. I agree warm air will go to peak but what is done with it from there make's a difference. This should have been addressed when plans were drawn for house. There should be a set of plans just for hvac that include's vent-a-hood and anything else related to air movement and conditioning.

What is your location?

Tall ceilings have increased temperature stratification - that is unavoidable.

People stress over vent location way more than necessary. Your return is low - how do you think the air gets there?

I lived in a mixed climate and like most around here, the downstairs has vents on the floor and the upstairs has vents on the ceiling. No difference noted. Our vacation house has vents on the floors on both levels - no difference.

My personal opinion is you are combining 2 things - one of which is real and the other is pretty minor. Tall ceilings are going to temperature stratify more than short ceilings. Vent location is minor. What is often done about the ceiling height is ceiling fans.

I am going to guess you are in a northern climate since you mention radiant heat in the floors. You would be far better off stressing about what your walls are like and what your windows are then vent location.

Is the floor a concrete slab? Where are you located?

I think having a supplies and returns at a height of 10 feet is not going to be a problem, but depending on your location and comfort level it could be. If a supply duct will be coming down to the 10 foot level, then it could be continued down the floor and attached to a second vent. Your builder needs to figure out how to do this. It might be difficult how given how the vaulted ceiling and walls have been framed. A chase could be built in a corner for the supply to travel. Perhaps it could incorporated as part of a closet.

Radiant flooring heating can be expensive. I think you are better served spending the additional money on installing additional supplies and returns than radiant floor heating. The floor heating will not do anything for cooling if the duct work has been poorly positioned.

Your builder needs to hire a competent HVAC contractor and work with the architect to come up with a good solution. I suggest you install a ceiling fan at the peak so it can move air in either direction in summer and winter.

Heating supply vents are best placed low, cooling supply vents are best placed high.

Thanks everyone. The gc knows I’m stressed about being warm, he said he’s not worried but can do the floors if I’m cincerned. He does have a mechanical engineer involved and has from the start. The issue is the architect never did this when he designed the home and it’s under construction now songbdy have been coming up w places to put the ducts.

if the vents are on a 19 ft ceding next to the start of the incline tonthe pitch (there are 10 ft ceiling that drop ) do you think the air will get sucked up? 9 zones as well. Think Reuters are in a different riom

Use a ceiling fan. Vaulted ceiling look great but are not as livable. Most design actual living spaces with lower ceiling heights an leave vaulted to dramatic areas.

I am very curious why hickory cant be used over a heated floor? Actually and heated wood floor has to be stressed constantly with the temperature fluctuation. Anybody who lives in say San Diego will tell you their house sounds like a pop corn machine at night as you hear all the wood moving when the temps swing about 20 deg at night. You will be doing this within minutes.

I would suggest an engineered wood floor would probably best due to the stable substrate. Although I have had with 10mm wood facing that is technically refinish able and it still moved quite a bit like a real wood floor.

I always thought distressed white oak was old world french? I would take an oak floor over hickory any day of the week. Oak is a solid wood and more stable which probably just answered my own question as to why not to use hickory.

I guarantee you couldn't tell the difference if they finish to your taste and I really think you need an oak floor as hickory in France???

I use to design duct sizes and vent locations when I first started drawing houses. I showed up on the site and they were rarely where I showed them, so I stopped designing the HVAC systems.

I hope that the builder is not suggesting radiant as a backup heat source. That's preposterous. Are they proposing electric mats or a boiler. Is natural gas available for fuel? If you are going to have it, it should be primary and run with a boiler if gas is available. You can do Hickory with radiant floor heat. It's exclusion sounds like bologna to me. Among hardwoods typically used in flooring, its potential to swell smack in the middle of the range. You probably want quartersawn (which costs more) and you have to make sure it does not get too dry. With new construction, the dry part should not be difficult, but you might need a humidifier. (Dry air in the winter comes from leaking air in leaky homes. Moisture will be a problem with a new slab with wood over it, but that is probably not unique to a heated floor.

With forced air, ideally, you'd have both high and low supplies and use the higher ones for cooling and the low ones for heat. Why can't that be done in the walls? I am worried about this home construction. It seems like you are being
take for a ride with these two aspects so what else are they lying to
you about? A paddle fan in the room to reduce stratification is a band-aid that can work. On the other hand, if you have a well insulated and sealed home, the stratification will be less than in an old leaky home. On the third hand, if there is a lot of glass in this area, it is going to be near impossible to heat and cool without lots of money involved on a continuing basis.

An old world French home would be cold and drafty with its fireplaces so why are you installing heat at all :-}

Can you have supply vents in the walls, low to the floor? Where's the furnace?

We have floor supply and two sets of returns across the rooms in the walls: One high to draw cool air up; One low to bring the warm air down from where it rises to the ceiling.

Our contractor hired a novice HVAC guy and we needed to add under-floor heat in two areas on the north side of our house. We have an unfinished basement -- no problem stringing tubing and adding a small boiler. Under-floor heat is *the best* for cozy warmth. It does affect a small portion of our hardwood wood flooring in the library. (Could have been allowed for had we known we needed the supplemental system.) I am glad we have the forced air system in that room to bring humidified air from the flow-through humidifier on the furnace.

Ceiling fans...meh. Yes, you can adjust them to blow up or down...somewhat. I don't like how low they have to hang to be effective.

Here is another thought, radiant floor heat with limited floor space (ultra high ceilings) might not work. It is a matter of geometry.

So we opted out of the floor heat builder suggested only bc I was/am so scared of not being warm. He said he was confident as is the mechanical engineer that I’ll be good. They have 4 vents on the great room at 10 ft and 3 in the kitchen at 10 ft-kitchenopems to great room. So the great room is 10 ft ceilings then high pitch to 22 then 10 ft again. They have 9 zones for heat and air

our vacation home has vents at ceiling height. (8, 14, 20') the a/c is great in summer, but winter sucks. where ceilings are 8' you can hold your hand up and feel the heat before it disappears. other places, lots of whosh, no heat. i hate going there for the weekend in winter. i could never live there year round. a fan does NOT HELP.

Ionized: they can’t go under floor as the crWl space is only 18 “ so soloutukn is putting vents o we head-4 in the great riom on the parts of the ceiling that are 10 ft flat. Hard to explain but it’s like: ———-/. / ————. The / / being the pitch the lines being the 10 dt kocations

How many vents in the cold room? What is the temp outside?

the pros can judge, but I don't see why ducts can't go into an 18" crawl space.

18 inches in a crawl is plenty.

9 zones is patently absurd. Have them describe how many actual units are being used and how many zones on each unit. And why would any reasonable house need 9 zones?

2 per floor - max. And even then - rarely done right.

Think 2 units?

Large home

Square feet and number off rooms are what? Are there special needs that might require extensive zoning meaning variable heat loss season to season or time of day?

Large home sqft wise. Think he added zones for extra assurance for me as I’m so paranoid about the vaulted great room. No snow here -northern cal but winters do get cold

Bring your plan to a local hvac contractor for evaluation. Ask him about ways to use the 18" crawl space. I feel your contractor is limited because he's outside his area of expertise. Get a pro involved for new ideas. We used a ceiling trunk with supply runs down the walls to vents near the floor. This is an option that doesn't need to use the crawl space. The heat distribution isn't a problem. You don't need multiple zones in this one large living room/kitchen space.

How does one control 9 HVAC zones? The builder installs 9 zones, and then suggests radiant heat flooring could be installed as insurance in case the 9 zones don't keep you comfortable. The builder wants to install radiant flooring heat because duct work can't be installed in the 18 inch crawl space.

I am not getting a could feeling about this HVAC installation.

Jeanking, I didn't see an answer to the "where are you" question, but for my new home in northern NY, I have radiant in both the concrete basement and solid oak main floors, and it works very well. We recognize that it is very slow to respond, so we don't change the temperature (unless we are away for an extended time). When we are away, I set the temperature to 40° or 50°. When we come up in the winter, I remotely increase the temperature in the two main rooms to 70°, but it hasn't reached that in the six hours it takes to get there, but that's OK, we like to sleep cold!

The builder put in 8 zones, because there is a limit in the length of a hydronic loop and it was easy to put each loop in its own zone.

The only problem with this system is that I didn't think we would need AC in this climate, but this recent heat wave has made me rethink that. However, it was excessively hot for only 5 days. I'm thinking about putting a mini-split heat pump (see another thread of mine in this forum).

Just a note about small radiant zones, They can be a problem with fossil fuel boilers due to short cycling problems. People don't seem to like to use buffer tanks to fix that, but they are a solution. You are essentially replacing a mass of iron in the heat exchanger with a mass of water. Sometimes when installing replacement boilers and switching from high mass boilers to low, hydronic designers will recombine zones that were split up decades ago when fuel oil prices shot up,

Northern Cal - no snow. Cold?

It is always so fun to hear what people think is cold or hot. Everyone seems to think their climate is extreme.

If you don't get snow - then you aren't at elevation - correct?

If you are not at elevation, then you don't get cold by what many in the US would think is cold. Sure cold for Palo Alto. But true cold is Minnesota.

It is like when people complain about NC (where I live) getting hot. 5 days above 95 a year is what we are. That is not hot. AZ - that is hot.

I was a little crude/rude whatever with the absurd comment. But don't ignore what I said that zones are rarely done correctly. My last house was zoned. It was 6000 sqft and we had 2 units with 4 zones total. One zone was the basement - that is pretty typical and required by our codes. Then we had the master suite separate from the rest of upstairs. We had an infant and we like to sleep cold - like 60 winter, 65 summer.

No zoning this time because despite Carrier Infinity having the most sophisticated zoning system available in conventional residential HVAC, it was not great. Mostly it was not great because we went through 2 motors in 7 years. It was an install issue - but the ducts were large and so were the returns.

But 9 zones might make sense if it is a 10k sqft U shaped 3 story house. But what I see is a degree of paranoia about temps leading to an overengineered system. That system will break and it will happen more often than a simple system.

CA codes require better than average US insulation relative to climate. This goes a long way towards making a comfortable house.

Thank you David-helpful info. House is 7000 sqft-paranoia probably but on my end. He did have a mech engineer do this who has 20 yrs of exp -trying to have confidence on my end

A mechanical engineer may not be a hvac expert. I'd get a second opinion.