Newbie to the idea of radiant heat in a 1200 sq ft home

hot_rod

One option is panel radiators for all the upstairs rooms. Really not a lot of benefit to radiant floors under beds and dressers. Easy to control and do minor setback, with steel radiators

So the lower floor is 1500 sq feet with a 34,000 load.? If so that can be done with radiant, easily.

Hot air rises, so with forced air you will get that temperature stratifying upstairs.

Radiant will not do that, it is a line of site energy movement.

Think of a cold winter day, you walk out from behind a building and face into a bright sun. In a second or two you feel the warmth on any exposed skin
That is radiant heat transfer. It travels at the speed of light from 93 million miles and you feel the energy almost instantly.
So your radiant floors, or walls, or ceilings move heat as radiation, warming whatever is in their path or in contact with the surface through convection.

Radiant walls or ceilings can get you a bit higher output, as you can run them a bit warmer. Unless you plan on walking on them 😳. It may be a better option and you could leave the ducted system in place for back up, air filtration or AC

psb75

And on that sunny winter day, if your are wearing black clothing... + +

Josh342

@hot_rod the house basement measures 30x26. So it's almost a square.  So that comes out to 780 sq ft.  The upstairs is different because of the sloped roof and that there are cavities enclosed within the corners. I have one corner that is open (not insulated). That will be taken care of soon. The cavity off of my daughter's room was just insulated.  The attic has insulation laid out plus around 8-10 inches of cellulose.  I need to add more.  So there is room for improvement before working on heating.  But for the main, I would only be needing to heat 780 sq ft. 

Gordy

hot_rod said:

I know the feeling, I have lived in, currently do, a forced air home. I buy thicker and thicker sox trying to keep warm feet when sitting around. Nothing compares to properly designed and installed radiant floors for foot comfort. And peace and quiet heat😁

Lived in a FA slab on grade in the Midwest. Newly built. Slab at exterior wall 54* at -10 OAT.

talk about sucking the heat out of you😂. Slippers a necessity. Worst part is 1/3 was ceramic tile….Concrete without pex is a wasted opportunity.

hot_rod

Josh342 said:

@hot_rod the house basement measures 30x26. So it's almost a square.  So that comes out to 780 sq ft.  The upstairs is different because of the sloped roof and that there are cavities enclosed within the corners. I have one corner that is open (not insulated). That will be taken care of soon. The cavity off of my daughter's room was just insulated.  The attic has insulation laid out plus around 8-10 inches of cellulose.  I need to add more.  So there is room for improvement before working on heating.  But for the main, I would only be needing to heat 780 sq ft. 

The more you tighten up the structure, insulation, air gap sealing, the lower the heat load.

So when you do the calculations be sure to use the values with the current or proposed upgrades. Money spent on structure upgrades lowers the component costs for the new system, and reduces the fuel consumption for the life of the home. One of the better places to wisely spend money. Then design the heating system.

Realistically you can put 25 btu/ sq ft into a residential with a radiant floor design. If your load is larger, you may need top add some supplement to the floor radiant.

Call your 1st floor 750 sq ft, since cabinets, etc subtract out. 750 x 25 btu= 18,750 btu/hr. If the load for the level is at or below that, you are good to go with radiant floors.

The top level will be a tougher load, more outside exposure. In bedrooms you cannot count the entire floor as output. Anything that covers the floor, beds, dressers, nightstand, blocks the radiant energy available. I'm not a huge proponent of radiant floors in bedrooms.

Radiant walls are a nice, sometimes easier to retrofit option. Notice the output difference

Or just do panel radiators throughout?

Hot_water_fan

The attic has insulation laid out plus around 8-10 inches of cellulose.  I need to add more. 

Adding insulation on top of this much existing insulation is a poor use of money - payback is essentially never. 

hot_rod

Some insulation recommendations.

go to www.dsireusa.org and see what incentives are available for weatherizing your home. Then see how the $$ work out for your home.

Gordy

If done correctly Insulation and weather sealing is the gift that keeps on giving. I’m not so sure ROI is a huge factor compared to other products with a life cycle.

Josh342

Guys, I didn't mean to ghost this discussion.
I had some medical stuff come up and the whole radiant project took a back burner. Within the course of my research last year, I had found some good and not so good information on Radiantec. At one point, I had reached out to them for a quote and their prices were very high. Fast forward almost a whole year, I am finding their prices to be consistent with how much things cost now. There are a few things that I feel are out of line with their quote though.

I have attached their quote along with some other information. Since this post, I have done more insulating of my house and I need to redo this slant fin calculation.

Looking for thoughts on what they have proposed. I have no intent in going with them but interested in how you feel about the parts that were chosen.

The long term plan would be going with radiators upstairs, so I will need to account for that.

One thing I noticed is the amount of zones they are calling for on the main floor - kitchen, bathroom, master, dining, family room.

Also, what are your thoughts on their pick for the boiler?