Radiant floor heat question.

I am just getting started on a project and one of the things we are deciding on is radiant floor heat. In the kitchen for sure we are going with tile and are going to put radiant heat under it. In the adjoined dining/sitting-tv room we don't know for sure if we are going carpet or tile. If we go tile the job of finding radiant heat is not too bad. If we go with carpet we are going to put radiant heat under that because it is a room that has no basement and the room does not heat evenly which leaves it sometimes uncomfortable in the cold season.
For tile floors are there any recommendations that you have for a good radiant heat. I do have some that I have found that look good but some of you have some good pointers.
The hard one is if we do decide to do carpet there has been a very limited choice to chose from. Anyone with some good leads? Thanks.

Because of the no heat issue under the room it tends to be cooler and uncomfortable. Is there anything else a person would suggest to use to help out the situation?

What do you have for a heating system now? Electric rates in many places are pretty high, and space heating with electric can be quite costly. If you have a boiler, then you have other choices. Another question to ask yourself is how high can you stand to raise the floor level? Hydronic can be done as staple up or embedded. Staple up is often not as efficient as embedded. A large thermal mass makes for a more even temperature, and embedding hydronic in something like light concrete or gypcrete can work well, but both of those will raise the floor level a fair amount. A carpet will act like insulation, and the response of the radiant will slow. In either case, you'll want good insulation below. There are electric (and hydronic) radiant panels that might work for you. These tend to heat the occupants more than they do the structure. I don't think anything beats a nice warm floor in the winter, though.

If you just want to take the chill off, verses provide the primary heating, then under tile, electric can be effective. Having it sufficiently dense to provide primary room heat may not be possible, depending on where you live - climate, building structure, and preferences will vary, so it may not be possible or ecconomic. Generally, you can get more heat out of hydronic for less money and engineer ti to overcome any heat requirement.

We have forced air heat with 2 vents now but even with those 2 it seems cool. The reason being that the area beneath this room is not a heated area and makes it uncomfortable sometimes. I am going to add a third vent but since we added radiant to our bathroom we really love how the air temp in there is so even and comfortable. We are primarily looking for electric radiant heat to help us out.

If we do decide to go with carpet in the one room, I have found a carpet pad that is great and they say the R value is 22 with that alone. What other alternatives could I use instead of radiant heat to keep the room warmer. One more vent should help but is there some special insulation I could use or some that is better than others. Is there a reflective material I could use between the joists or something to put down before the plywood goes down? The problem is that there is no heat coming from under this room. I am planning on insulating the heck out of it.

If we do decide to do tile than radiant is a must no matter how well I insulate the floor and space below.

The carpet pad that advertises R22 may not provide that value in many situations...it likely has a radiant barrier in it, and that is an effective R-value, not always obtained. In a conventional sense, it might be the equivalent of maybe R2.2 (did you miss the decimal point?).

Keep in mind that insulation doesn't make heat, it only slows its movement down. If the floor is cold, it could be from normal stratification, or is could be aided by the fact that it is losing more heat to below than is being added from the top. Slowing that will help, but not stop that effect. A radiant floor is probably the most comfortable heating you can have. Electric heat mat under carpeting may not be a very ecconomical choice.

You might want to consider spray on closed cell foam insulation under the floor.

With the R-value I swear he said 22 but I may be wrong and he may be wrong. He did make a comment that it has twice the R-value of standard pad.

Adding another forced air vent should help somewhat,don't you agree?

Where would I get spray on insulation? DIY project?

Spraying insulation is best left to a pro. Now doing that in a crawl space is likely to cost you. With forced air, the location, volume, and incoming air temperature will affect how well the air is distribuited as will having a proper air return. you might find that adding a dedicated return duct would exchange the air better than what you currently have. If there are any air leaks and drafts in the wall or crawl space, that will make the floor colder. With forced air, you can't just blow lots of air into a room without an engineered path for it to return to the furnace to be reheated. You want the ducts down low so the heat is inserted into the room low, so when it rises, you don't end up with just a hot head. In some homes, they have the ducts in the ceiling, which is best for air conditioning, but lousy for heating.

It will be almost virtually impossible to add a return to this room unless I could just add a vent in the upper corner of the room and continue it to the other room on the other side that does have a return air vent in it.

The least effective place for a return line is up high. you want to return the colder air stratified at the floor, not the hot air up top. This promotes more even air flow in the room.

So, what if I put a vent on in the corner on the bottom of the wall on both sides. The return is about 20 feet away but do you think it might have some pull?

The requirement for a return somewhat depends on the room. For example, if you can close the doors to the room, separating from a return somewhere, you will find it hard to push hot air into it. But, if the return is not sized properly, even if it exists, it won't help much. You want as much air returning as you are trying to push into the room, or you will disrupt the airflow, which can result in not meeting the heating/cooling requirements and therefore comfort. So, the effectiveness of all this will depends on the location and size of the return. Can't really say without knowing sizes and location.

If the room and airflow is never closed off from the return, an extra opening through the wall to a place where the return is won't make any difference.

It is never closed off. It is a 10 foot opening.

In that case, if there is a return that is accessable (i.e., not in a room with a closed door), it probably wont' make much of any difference. What might help is if that return is undersized, and you put in a new one that was larger.