Does anyone have have any energy modelling data/feedback/experience on the performance characteristics between Warmboard and a standard 1 1/2" gypcrete floor system? Specifically, I would be interested in the long term comparison (6 months over the course of a heating season for instance). I have viewed Warmboard's presentations and studies on thermal conductivity vs mass and it totally makes sense over a short time period and the fact that the comfort level can be reached quickly. If a gypcrete system takes 12 hours to get to the right temperature (overnight?), would the operating water temperature required not be lower from that point on? Would I be correct in assuming that thermal mass would 'hold' its temperature more consistently over a longer period of time requiring ultimately a lower water temperature supply? Has anyone done an energy comparison between a step back thermostatic control system (higher fluctuation in cycling energy off and on) vs a lower more static temperature of a thermal mass system over a more sustained period of time? Thanks.

Warmboard is not as effective at extracting the heat from the PEX as Gypcrete so a slightly higher supply temp is required to achieve the required floor surface temp to generate the required heat gain. Warmboard is much more responsive than Gypcrete allowing the use of night time setback which you wouldn't use with higher thermal mass HR emitters like thin Gypcrete slabs or normal thickness concrete slabs. Energy efficient buildings having significant interior thermal mass are very insensitive to outdoor temp swings and don't require a responsive HR emitter. So what is best or what you should use largely depends on how the building is constructed. And how the building is constructed will have a much larger effect on how much energy will be expended for heating than whether you use Warmboard or Gypcrete.

I agree with what is said above and would add.....in my last 2 builds we have laid regular concrete 1-1/2 thick over osb with pex laid first.

This is the cheapest and easy. And easy to find a concrete crew to do it. I put down 2x6 where the interior walls would later go and the cement guys could just screte off that. I attach the pex to the OSB with rebar ties and chicken wire staples.

For finishing you can do a floating floor or tile. I haven't glued to the concrete yet but that might work.

Good Evening,

I am in the design phase of my renovation/addition to my home in Rockland County, NY. I am looking at warmboard as an option for my first floor and base ray for the second floor. From your statement above " So what is best or what you should use largely depends on how the building is constructed", should I wait until the building ennvelope is constructed with fenestrations and do a door blower test to decide my heating and cooling methods? Is this foolish to wait that far into the construction to decide what my heating and cooling package should be?

Lastly, Mr. Borst with your all your knowledge, are your expertise for hire in the design of a heating and cooling system for my project?

Thank You

What you use will likely be influenced by what your floor system can handle. Warmboard is a lighter approach, but the product/material is more expensive. Which approach will be more expensive overall will largely depend on your local installation labor costs for each approach.

How you construct your building envelope has as much if not more effect on your overall building energy efficiency than the efficiency of your heat source. Yes, a heat pump system is more efficient than an electric boiler. However, if you have a very well insulated and sealed building envelope that takes advantage of passive solar cooling/heating design features, the required heat gain provided from your heat source can get very small which makes the heat source efficiency less significant on your overall building energy efficiency.

You can contact us via our website. Depending on our schedule commitments and your schedule requirement, we may be able to work your project. We also have DIY design software on our website if you are so inclined.

And lastly, this is Mrs. Borst (Gayle) and Mr. Borst (Bob) pretty much always does what I request...so please keep that in mind...