Looking for recommendations

robert griggs

for a job I am bidding on. The customer is putting on an addition to his home. This addition will be 30' x 20', and have a full finished basement with one bathroom. The problem I am having is the upstairs- it is going to be a Florida room- all glass walls and a glass ceiling. I would like to do radiant heat, as the floor is going to be tile, and this would be wonderful in the winter. The only problem is that the heat loss I figured is approx. 86,000 BTU, and there is no where near enough floor space for radiant only. I was looking for advice on other heaters that you would use along with radiant in this situation.

The customer was thinking about installing split systems- wall mounted heat pumps and air conditioning systems. That would be okay, but I don't think that would work too well with radiant heat. Wouldn't it stir the air up too much for the radiant to be effective?

Other than that, the customer would like to have forced air heat, as he has it in the rest of the home. I was thinking of maybe duct work for the A/C, and baseboard in the finished basement, along with radiant and supplemental heat in the glass room.

By the way, does baseboard stir the air too much to use along with radiant? There is not going to be enough wall space to put it in to cover the heat loss.

Thanks for your help.

R. Griggs

Rocky

Robert,
Here in Fairbanks, Alaska, we get alot of jobs where the radiant just won't do it by itself. To address this problem,
I have used Buderus radiators as supplemental heat when the btu requirements are higher than the radiant can provide by itself. They take up very little wall space, as opposed to baseboard, are aesthetically pleasing, and deliver a lot of heat. Use a two stage thermostat. First stage turns on the radiant, if it can't keep up, the second stage fires the hi temp rads. Hope this helps.
Rocky

Dave_4

70 btu/sq.ft. ??

...buy more insulation & better glass...use floor registers at the glass walls....an AC unit w/hot water heating coil off the boiler might be more efficient than running the heatpump compressor & the boiler in the winter

ta finnegan

Options

Air changes are critical when it comes to radiant. Be careful when it comes to this or the radiant will just be a cute feature of a room not well heated by the split system.

Either size the split system to to the whole job and have the radiant provide "warm tile" or boost the radiant side with slick looking radiators. I agree with the previous posting about Buderus.

By the way there are alot of really neat radiator companies specifically England and Germany that you can find on the web. Most of them have some distribution here.

Also, there is a company here in the Philadelphia area that has tremendous glass - Four Seasons Sun Rooms I think.

Good luck.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Chris Maderia

Heat Loss

I'd check that heat loss again. I ran it using 12 Ceil's with a R-value of 3.21, 2 30' Outside Walls R-Value 3.21, 1 20' Outside Wall R-Value 3.21, R-19 in Floor using a 0 degree design temp and a 65 degree room temp. My heat loss was 34,434 and that included 15,000 btu's of supplemental heat. Using Quik Trak you would get 19,434 out of the floor with a 119 degree water temp and a floor surface temp of 80. If I'm missing something let me know.

Alan(CaliforniaRadiant)Forbes

That's 143 BTU's per []

Whew; that's tough.

I'm with j to increase the insulation to reduce the heatloss and then Rocky's suggestion to do a radiant/radiator, 2-stage heating system. It's a lot of work for 600 [], but worth it in the long run.



To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

hot_rod

It's the glass

that kicks your as-. Even the best triple pane pales compared to insulated frame wall. I'm not convinces R-3 or even close, is a number you can use with glass, realisticlly. Even with top of the line glass, you still have the glass to frame work connection to deal with (infiltration load) They rate R values for glass in a funky way.

Also keep in mind the incredible solar gains in a space with glass walls and ceiling. That will be a real oven, come summer. Run a heat GAIN calc on that space for a scary number

hot rod

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

ta finnegan

The glass

The glass these 4-Seasons guys use rates out at an R-4. Not bad and the joinery is tight.

When I design for these, the heat is the toughest part the cooling is tremendous because of the UV coating on the glass, it does a tremendous job with heat gain.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"