Hi, I'm building a cabin/cottage in Northern Ontario where winters can get very cold. The building is modern in design and is on steel stilts exposed underneath for most part. Our contractor is planning on using 10.25" SIPS panels for the floor and roof. There will be a lot of large modern windows. We are trying to determine the best heating system which will also play into the type of flooring used. We are considering using a water in-floor radiant heating system with gypcrete. So basically as I understand it: SIPS panels, radiant system, gypcrete over top and then the flooring. Is this practical and cost effective solution for this project? Are there alternatives? I've been told forced air is out of the question given the SIPS. Also a rad system would be bulky and take up space. The contractor is worried that with blowing winter wind underneath the building, the radiant system may not be warm enough. He also thinks we shouldnt go with hardwood floor as it will work against the radiant system. He suggested concrete or tile instead. My other concern is with gypcrete. I've been doing some online research and have been reading some horror stories about this product. Can anybody give some perspective? As an aside, Ive also read in a magazine about just leaving the gypcrete as your flooring by sanding it and treating it with a water-based sealer to get a concrete look for a fraction of the price. If anyone can help with these issues Id be very appreciative. Having an effective built-to last heating system is a top priority for us. We also dont want to spend more than we have to. Any insights would be helpful. Thanks!

I do have a solution. take a look at our product.  www.warmfloor.com   You can put one inch hard foam insulation down and put our product on top.  it' only 1\8 of an inch thick and very green in use. It's is compatable with all flooring, including all types of wood.

by the way, It's electric, 24volt electric. It's was developed in norway and is very efficient. If you haven't yet seen it you need to take a peak.

If you would like to call me I would be glad to help get you some numbers and some cost comparisions for year to year operations.

[email protected]   

office 866 360 9276

Joe Myers

Thanks Joe - I will take a look at your site. Are there studies that compare the cost of running an electric radiant system vs. a hydronic system? My initial thought would be that electric is much more expensive in terms of your annual utility bills. Bear in mind that this building is in Northern Ontario where is cold from October until May and can get as cold as negative 30 C in the coldest months. As I research electric vs. radiant I feel like electric is the best option but I have read nothing about the comparable cost of running the system. Anyone else's perspective would also be appreciated - it would be nice to hear from non-dealers on the subject (no disrespect but obviously biased!) Thanks.

We do have studies.  and we would be glad to give you a cost comparison hydronic vs forced air vs warmfloor.

All we need is the cost of electric in your area, home plan and some insulation #'s and we will give you the cost comparison that you can comb through.

 

joe 

1 kwh = 3,412 BTUs.
1 gallon of propane = 87,000 BTUs in a 95% efficient boiler, well designed and controlled.
1 gallon of oil = 140,000 BTUs in an 85% efficient boiler, again well designed and controlled.
1 therm of natural gas = 95,000 BTUs again with 95% efficient boiler.

it's easier to screw up a hydronic boiler than an electric matt, so the chances of getting inefficiency are greater for sure.

to compare yearly costs in your area, you'd need to have a heat load calculation. but you can take a current fuel bill to estimate what kind of range you're in: take what you used, convert to btus, covert to electricity, compare costs. Electricity rarely... but sometimes... makes sense from an operational cost perspective. Usually it's cost prohibitive to run.

if there is any variability in your local fuel market, hydronics have a pretty big advantage there in that you can change heat sources later without tearing up your floors.

Heating the floor (vs interior radiators) means that you need to use somewhat more insulation under it to get the same through-the-floor heat loss. Big question is how many hours/year will you be heating it and is it designed for easy winterization (ie, heat turned completely off)?

Concrete costing more than gypcrete doesn't seem right to me.

thanks for the info so far gents. from this post + other online info, it seems like for a building in a cold climate, a competently installed hydronic system may be a more practical solution than a competently installed electric system. I'm still nervous about the potential maintenance issues with hydronics i.e. leaks, sediment build up, cracks etc. Are there associations or certifications in Canada that provide assurances for workmanship? I'm also a little concerned about what I've been reading about the potential issues with gyp-crete. Its hard to tell what's fact and what's just banter between competing product suppliers...

How many square feet?
Access for cement truck?
Walls of glass or modest glazing?
Might consider a floor panel system, We distribute RHT Floor panel system, there are others similar. This can nail directly to the sips and your wood floor can nail directly to the panels. Easy owner install for a couple moderately talented people. accepts 1/2 inch pex pipe.
I have never heard of using Gype Crete to make a finished floor look like concrete. However You can use light weight concrete poured 2 1/2" thick. This works but will crack.
Might consider an electric boiler with a anti freeze mix.
Might consider the same with a modulating condensing boiler.
Dan

Thanks Dan, 1600 sqft, side-split concept. Yes access for truck. Substantial windows but not floor to ceiling. Is wood flooring and radiant counter-productive? What about heat loss through the bottom of the exposed cantilevered sections? I know radiant is used in cold climates its more a concern of radiant + cold climate + cantilevered sections...

I am not sure the R value of a 10 inch Sips but could guess it might be R40 ? Don't see a big issue with the cant sections, The pros and cons of a light weight cement ( not to be confused with Gype crete).
The cement product can make a nice finished floor with an acid wash stain, It will crack, but scored properly right after pour (day 2) it can look good and will hold nice heat mass.You can also do a floating hard wood over this and a traditional nail down if you place sleepers on a 12 inch patter and infill the cement.
The RHT floor panel system works well with traditional nail down floors and also floating wood floors.
Both of these system types (floor panel and concert topping pour) work nicely with a low temperature delivered water temperature that a condensing boiler or electric can provide.
If you are in the out back though I would be inclined to use an electric boiler, there are far fewer parts and you can keep the needed spares on the shelf.They are a simpler beast for most mechanics to work on.
Dan

Hi, I am not a heating expert, but we are currently building a home in Ontario and are having radiant in-floor heated by an electric boiler in the basement and main floor of a bungalow. In the basement we are having the concrete floor stained with water based stain and the main floor will be all tile (Timberlands wood-look for living/dining room and bedroom). I wouldn't call wood and radiant "counter-productive", but what you want is the best transmission of heat from the water to your feet. Concrete is a good conductor, tile is a good conductor (and both of these will absorb solar heat thorugh south facing windows in winter). Wood is not as good a conductor, but is better than carpet. Also I believe that to ensure you have adequate heat in cold winters (especially with the house underside exposed) you should have a heat loss calculation done. To increase the heating capability of the system, more loops of hot water tubing are needed. Good luck!

http://www.buildingscience.com/documents/primers/bsp-035-designs-that-work-very-cold-climate-juneau-ak/section-2-the-basic-very-cold-climate-house

If you use electric heat, then how good a conductor the floor is has little to no effect on energy efficiency. On the other hand, geo, solar, gas and oil can benefit from the lower temperatures involved with concrete, tile, etc.

What?
you will place a pipe in floor under wood floor or in slab
You will place a piece of wire under wood floor or in slab
Both will be met with the same energy resistance. conductor issues.
Dan

this is great - thank you

what made you decide to go with hydronic radiant? are you using gycrete in the main floor? are you concerned with future maintenance issues i.e. potential leaks, etc?

From all of your comments, it seems that I did not make myself clear about my project.

We are not using electric heat. We are using a propane boiler to heat water -- to heat concrete -- to heat tile -- to heat our toes.
We did not consider electric here in Ontario because it is so expensive. I have propane but not natural gas.
We did not consider wood floor because it is not a good conductor, but since I love wood, we picked a wood-look tile, which I hope will be a good substitute.

Justin_toronto: We decided to go with hydronic radiant because of the comfort level. I think that we can use less energy to heat our feet that we used to heat our heads! Especially since the new house will be much more energy efficient that the century home in which we have been living. We are building an energy efficient LEED home (maybe gold certified, have to wait for that!) and we are trying to do everything as green as possible, given our budget. It is not easy to decide. We are going to use concrete on the main floor. 1 1/2 inches thick. It is new construction. We are not concerned with future maintenance- leaks, etc. because I am convincd that hyronic in-floor heating is a proven technology, especially since the pex tubing has replaced copper. Let me know if you have other questions. I can tell you how the heating works out for us , but not until next November or December!

Cheers,
Sandy

Thanks Sandy. What are you using for insulation?

Under the floors (which unlike yours, are in the ground) we are spraying foam insulation under the concrete. The basement walls are ICF. The main walls are on 24" centres and are sprayfoamed to seal, and then batt insulation. We are building to LEED Canada EA 2.2 Enhanced insulation requirements. See

theCanadian LEED standard is 151 pages long, here is a link: http://www.cagbc.org/database/rte/LEED%20for%20Homes%20English%20090420.pdf

I do not know anyone who has done this before, so are just hoping that it works out well for us! call me pioneer girl....! :-)

why did you decide to go LEED? It seems like an interesting concept but looks like you really need to have this as a goal from day one...thanks for the info