We are building an 11,000sqft home in an area that is very cold 9 months out of the year. We will have a basement,main and upper level. On the main level and in all the bathrooms(9) there will be hardwood and tile. I also have extremely severe allergies. My builder is pro forced air, I am thinking radiant might be better ,at least on the two lower levels. We will have forced a/c for the three warmer months. My builder swears the forced air can keep the temperature constant (I have yet to esxperince that in any home) and the air clean enough for my allergies. Any input, studies etc. would be greatly appreciated.

As a homeowner who has lived with both, I can tell you your contractor is full of hot air (pun intended). With hot air, you're either hot or cold. With radiant the temperature is much more even. Plus, hot air has all the respiratory problems associated with circulating heated air - dust, pollen, etc.

If you want some medical studies, check with your Dr. Radiant is the way to go.
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Josie

[This message has been edited by Josie (edited 02-07-2005).]

Your builder needs to be reminded who he works for. Be careful he doesn't throw a large number at you just to scare you off of what you really want.

Tell your builder that YOU will find your own heating contractor and forget the "allowance". That way you can get what you want. If he doesn't like it, get another builder.

Hot air vs. radiant? That's akin to bringing a rubber knife to a gun fight.

I've lived with all types of heating systems and as a professional PHVAC contractor, I finally settled into a radiantly heated home we built from scratch. It took more scratch to build with radiant, but I have NO regrets. If I were to build again, or move to a previously built home, the only heating I'd settle for would be radiant.

So, you've got to decide what's important for you and your family.

If you were to rate your comfort issues on a 1 to 10 scale, where would that fall?

If you were to rate your desires for avoiding the dust and allergy problems, where would that fall on a 1 to 10 scale?

If you were to rate your desire for long-term energy conservation (aka - building green), where would that fall on a 1 to 10 scale?

See where I'm headed? Decide which things are important for you and your family. Plot out how they affect you and your family and assign a level of importance to each item. When you've finished, I'll bet you'll find the weight falls squarely on the radiant side. When you really stop to study and analyize the issues, money becomes a secondary issue.

Invest in your future - install radiant.

My wife, son and myself, all suffer from dust and pollen allergies. Our previous home had radiant baseboard heat from the '50's and it was very nice, although we had way too much carpet. We moved to a home built in the 70's with forced air electric, and it blew. I'd say sucked, but you get my drift. I gutted the forced air system two years ago, and installed in-floor radiant and have absolutely no regrets. It is an entirely different house. I give two thumbs up for radiant comfort heat. I agree with the others above. Your contractor just doesn't know radiant, and therefore wants to steer you away from it. Don't be fooled. Of course, I'm not biased or anything. ;~}

Thank you for the info from everyone. I am convinced, but my husband has a concern that he won't be able to control the temperatures of specific rooms, (ie his office) since he prefers cooler temps. We have considered doing just the basement, he thinks enough heat will get to the main floor. I think not? Also what about hardwood floors, I have heard that radiant heat can be very hard on them. Any suggestions?

If I can make a suggestion, please reread the various postings from the last few months. Lots of great stuff there on zoning, hardwood floors and on heat loss. You won't get the information you need to make an informed decision without having a professional heat loss calculation done.

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Josie

My bedroom stays a constant 62* ,while the kitchen/dining area is 66* - 67*, the living room 69* - 71*, sunroom 68*, laundry ~ 66*, sunroom 68*, master bath has a warm floor and heats to 70+ quickly when the door is closed, mudroom adjacent to kitchen hopefully will stay <60 as designed once I get the door installed.

Point being that with modern radiant design, and modern envelope insulation and sealing technique, it is definately possible to be very specific about which room is what temperature...much more so than with forced air.

From the sounds of it you are really building a huge house. I am in the process of building too. I can tell you, without knowing who or where you are, builders tend to be set on certain standards they are most experienced with. In my area, the two things that are vital to heating my home and keeping my wife comfortable are heat and insulation. They go hand in hand. My builder wanted to use forced air heat/AC and fiberglass insulation. It took time, but I convinced him that because fiberglass loses about 1/2 of its insulating properties in cold weather that was NOT an option. I subcontracted the insulators to use and alternative (which the builder now uses when he does not want fiberglass) and subcontracted an installer to do a hybrid HVAC system which is combination radiant in the basement slab, first floor and two bathrooms on the second story. The rest of the system is forced air with a mechanical room on the second floor to hold that equipment. I have spent weeks detailing ducts in the attic space and insulating them with foam cocoons. I spent lots of time doing this because my other home is super insulated with foam panel construction. At 2400 sq ft, we heat it and have domestic hot water with a 75K BTU boiler/hot water maker. Previously, we used a 60K unit, but it was replaced a few years back. The home has basement, two floors and a loft. It can be kept within a degree or two year round based on my design. That house has no radiant, but hydronic blowers for the hot water use. I have three zones, one for each floor.

The points I make by now are in order to assist you. Be sure you are addressing insulation first. Fiberglass is NOT the way to go. When you do this properly, your heating system will be much happier. You have many options. New air cleaners are wonderful in cleaning air. You are going to need this capability to treat pollen in the summer anyway. I don't see a way to get around it. I would not be scared of forced air. You can produce it directly with hot water coils or air. I would not be afraid of radiant but would tend to choose it for its comfort. Perhaps you can design the system to do both radiant and forced air. I like the idea of my hybrid system. If a furnace goes bad, I have radiant heat. If the boiler fails, the furnace will back it up. Just a few ideas for you to ponder. Good luck.

Thank you for the information and warning on the fiberglass insulation. I will take that up with my builder. I am learning that insulation is extremely important and have heard it's good to insulate the floor, including the basement slab. Any experience with that?

The more I research this heating issue the more I am leaning towards doing both systems also, similiar to what you are doing, and putting an air cleaner in to help allieviate the allergies.

Your large home would be an excellent application for radiant. Consider placing radiant in all of the living areas; the basement; the bathrooms and the master suite. You may elect to have baseboard heat in the childrens bedrooms to save on the cost. By utilizing a hydronic heat system you can install an indirect heater for the production of domestic hot water. If I was doing a home of this size, I would look at the cost of the different fuels and possibly consider geothermal.

Use the RPA website to locate a qualified contractor in your area and let him also talk to your general contractor.

Best of luck on your new home.

seems a little odd to have two entirely seperate heating systems. I would hybrid radiant floor with ceiling, baseboard or hydronic radiators in areas where you want to save money.

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Northeast Radiant Technology, LLC
-=RFH Design, Supply and Consultation=-
RPA certified Radiant Designer
http://www.NRTradiant.com
rob@NRTradiant.com

Hybrid water/air systems are fairly common in my parts. I look at it like this: After a couple years in their home, their next home will be all radiant. Or, they'll tell their friends to go all radiant. Just get some in there and you have your foot in the door. Sometimes, do to budget, you have to compromise.

Here is a link that will reference you to the Oak Ridge National Lab testing and conclusions on insulation.
http://www.betterinsulation.com/betterinsulation/OakRidge.htm

I doubt you builder will be happy to hear about this. But it is yours after all.

About the floor and slab insulation. My heating people recommended bubble wrap. There is considerable controversy about this and to be honest with you, I haven't reached the conclusion I did what is ultimately best, so I do not want to preach on this topic. I can tell what I did with the basement floor. I insulated the slab from the vertical walls with 18" of 1" foam board in order to keep the walls from contacting the slab. I used a perimeter of 8' of bubble over the radon barrier then wire mesh and wire tied the PEX tubing to the wire mesh. As far as the floors go, there is bubble stapled up now, but I am converting that to plates in areas where I have two story ceilings above and adding fiberglass to areas after I reposition the bubble wrap for better sealing around the perimeter. Ultimately they will go with what is cheapest and fastest to put up if you do not intervene. Be carefull and thoughtfull with your specifications and trust your instincts first and the contractor second. Good luck and hope this helps you.

Installing BB in the children's rooms will ensure they one day move out on their own(G).

That's great, but I'm having a hell of time trying to find the actual study referenced on ORNL's website. Anyone else had better luck? I saw one oblique reference embedded in another page on their site... and dozens more that never mentioned any such effect when discussing fiberglass.

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Northeast Radiant Technology, LLC
-=RFH Design, Supply and Consultation=-
RPA certified Radiant Designer
http://www.NRTradiant.com
rob@NRTradiant.com

It took some time but I believe the information on fiberglass is referenced through this very nice page:
http://www.ornl.gov/sci/roofs+walls/insulation/ins_01.html

There are many many references citing the Oakridge study, but I agree this is hard to find.

I hope this helps.

The key to comfort in any home is to limit the heat transfer where you don't want it to occur. Insulation/window choices, etc. play a big role, but the architecture is the place where an efficient house has to start.

If you home isn't under construction already, sit down with the architect and think about green construction techniques. Very simple architectual features can keep the summer sun out of the house and let the winter sun in. That way, you reduce your cooling costs in the summertime and your heating costs in the wintertime.

You might want to consult several resources besides older posts around here. For example, go to the buildingscience.com website and educate yourself and your builder about insulation/construction options. These guys have amassed a great amount of knowledge and have published three builders guides for different climates in the US.

Have a look at their housing plans, with an eye on insulation practices, especially around foundations. IMHO, there is no better system than to put 2-4" of XPS on the outside of your foundation and under the basement slab. This makes the foundation walls and basement slab a part of your conditioned space, adding a lot of thermal mass to your home and hence damping out temperature swings.

In-wall insulation should be impermeable, effective, and cheap. You can have two out of three... I would stick to Corbond or other in-situ applied closed cell foams because of their impermeability and amazing effectiveness. If you go with thicker wall construction (2x6, 2x8, or more), even Icynene or dense-pack cellulose become interesting.

The better your home is at staying comfortable with no heating or cooling, the less it's going to cost you to do so. If you want to go really high-tech, consider the radiant cooling and heating options from naturalcooling.com. This system will minimize the ductwork required to keep your home happy and is ultra-efficient to boot.

Anyway, I hate to say it but you may also want to consider going with a new GC. A GC that does not listen to customer wants and desires is a GC that is not suited to me. I'm just finishing up a 13-month complete gut job (including lifting the house to replace the foundation) and couldn't be happier with my GC. Look long and hard, because any house construction process is a ride.

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I found that page on ORNL's site, they don't mention the reduction of fiberglass under cold conditions in there. That was part of what is boggling me, if these results are solid, shouldn't they be in bold print in ORNL's own "things you should know about insulation" page?

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Northeast Radiant Technology, LLC
-=RFH Design, Supply and Consultation=-
RPA certified Radiant Designer
http://www.NRTradiant.com
rob@NRTradiant.com