hydronic floor

Rick_9

I am building with radiant floor heat on a 2 level house. The contractor is beginning the dig next week. He uses a plumber who does a lot of radiant round here but I have not had a chance to meet him as he is very busy. I have some concerns and thought I would run them by you.

The first item is in regards to the floor coverings. I am going to leave most of the house with just decorative concrete floors.I have heard this can create an uncomfortable floor. Can you give me some insight into this so I can feel informed when I talk to the plumber. Any type of pipe spacing formula which would address this issue.

Another issue is the number of thermostats. I have heard every thing from one per floor to one in every room. I plan to have a few on each floor but do you recommend running wires to each room to allow changes down the road?

I have been following the wall for a few weeks (although not understanding too much) but I get the impression that most of you discuss the system with the homeowner well in advance. Should I be concerned that the plumber hasn't felt I am a priority to discuss this with yet.

I have lots of large windows which will be getting the morning and noon sun onto the concrete floors. Should I be talking about slab thermostats or outdoor resets. I have read one of Dan's books but that only caused confusion.

I will admit I am very nervous about this and any advice from the wall could help immensely.

heatboy

How can..........

someone design a radiant floor heating system for you without actually talking to you about your wants and needs? I would halt the project until you have had a chance to talk to the installer or designer and find out exactly what will be done.

hb

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Dan Peel

Inputs

It's your project.
You'll be living there.
The regional control, boiler selection and a dozen other details need to be decided with your inputs. Don't let it slide. Dan

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Boilerpro_3

I'm with the guys above!

You seem to have the right idea about zoning and concerns about floor temperatures. Putting two room on the same zone when one is getting lots of sunlight, and radiant heat, and the other is getting a stiff northwest breeze makes for very uneven heating. Floor temperatures can also be an issue if glass areas are very large in proportion to floor areas (at night those big southern windows create heavy heat load). Sounds to me there needs to be a serious pow wow between the general, the heating contractor, and yourselves before anything moves forward.

Boilerpro

hot_rod

Only one chance

to get that slab tubed right

hot rod

Rick_9

thanks

All thoughts most welcome. Meeting is on, homework done. Thanks for all the help. R

Ross Lindley

For what it's worth, my two cents

I’m just a homeowner, not a contractor or tradesperson, but here’s my two cents worth anyway.

I’ve got 1 ½ “ of lightweight concrete throughout my house. From what I read, it’s the most efficient floor to have for a radiant system. And the stain really makes it look great! We have an area rug in the living room, partly so our baby had a soft place to play. There is no underlay, so the insulation value is not too high. And it only covers about 100 sq ft. Ceramic tile, which we put in the entrance, kitchen, and bathroom is also a great conductor for the heat and the concrete floor was an excellent base for laying the tiles.

The hardness of the floor hasn’t really bothered us, except when our daughter was learning to walk and climb, etc. I think the main disadvantage of the concrete floor is the slow reaction time of the heating system.

Our master bedroom and ensuite isn’t finished yet. One of the loops supplies heat to the ensuite and the sleeping area of the bedroom. Since we would like the bathroom to be relatively warm, but not the bedroom, I was thinking of laying carpet in the bedroom to cut down the heat there, while the tiles in the bathroom would give off plenty of heat.

I did quite a bit of research before deciding on a system, but still didn’t get all the bugs worked out. So my advice is to listen to the pros on this site and find someone to deal with who is going to help you get all your details sorted out. You want a system that has enough “brains” so that it knows not to kick in if your slab’s been getting lots of sun, or you’ve been cooking up a storm, or the weather changes abruptly, but not so many controls that you can’t find a rocket scientist to set it up properly for you.

[Deleted User]

Don't forget the Golden Rule....

Those that have the Gold, make the rules. It's your castle, make sure it gets done right.

If they don't want to play by your rules, find some new players.

Just my $0.02 worth...

ME

Big Al and the pipewrenches

Who is ...

living with it, paying for it, should be enjoying the benefits of the best in climate control. I agree with ME,
you are the man with the "Gold", you are the customer, you
should have the professionals that are most concerned with
you receiving the TOTAL and numerous values of radiant heat,
customised to each installation. For the whole project, keep
in mind it's your new castle, not theirs.
Good luck
AB

Rick_9

slab temp

Hey Guys, thanks for the courage. I've met with the heating contractor and he's a great guy. He listened, discussed, even got the circulator pumping away!

So the one thing I remembered from Dan's books was the slab is at 85 degrees. Why bother with an air temp thermostat, why not just measure the temp of the concrete in my in-floor hydronic set up to be?

Thanks again. Rick

Tom Meyer

Better late than never

Every time we meet with a client to design a system, the first thing we ask for is the blueprints. The second is asking their needs, wants and budget. We listen. We design. We then sit down and go over every inch of the system, operating processes and control strategy. One thing we ask is how the customer is going to use the house. That sounds like a strange question, but the intent is to find out about "crumb snatchers", decor, especially if the customer has a hardwood floor, etc. It's amazing their reaction when we say: "You're going to have a hardwood floor. That will look nice, but are you going to use area rugs?" Amazing how many times they say "Of course!" Doesn't that change things just a bit? Sure it does.

About the air sensing thermostats: the floor temperature is a design component. It isn't ALWAYS 85 deg F. Heating systems are dynamic. Things should constantly change to meet "comfort needs". Put in the thermostat to allow the zone to be adjusted to your comfort level.

Rule of thumb: The larger the mass, the slower the response time. If you want a fast response zone, use low mass systems (tube in track) with fast operating zone valves.

Senior Designer/Trainer
Precision Hydronics Corporation
www.precisionhydronics.com

Mike T., Swampeast MO

Slab Temp

Two-way controllers for slab temp do exist--just wish I had used them.

Heating systems are certainly dynamic but radiant slabs in particular deal with the dynamics differently than other forms of heat.

Since the exposed surfaces of a space cool as the temperature outside that space drops, you can almost view them as "sucking" the heat out of a slab. In that regard a slab maintained at 85° (or some given temp) can and will require more BTUs in to compensate for more BTUs going out radiantly as the outside temp drops.

A large thermal mass maintained at a given temperature can provide consistent comfort through a surprisingly wide range of outside temperatures. Solar gain in particular though can throw everything out of whack.

Rick_9

slab temp

Thanks Tom, makes sense to me, R

Rick_9

slab temp

Thanks, another item for the wish list, R