Thursday, November 15, 2012
Introducing RadiantPERT
What is RadiantPERT?
RadiantPERT is a new type of tubing manufactured from a compound developed by Dow Chemicals. The compound we use is DOWLEX 2344 PE-RT (PE-RT stands for Polyethylene Raised Temperature). This is the most flexible of the DOWLEX compounds.
Dow has been selling these compounds in Europe since 1982. In 1999 they began to develop it for the North American market. The standards are now at a point where we feel this product can be used for our radiant applications.
One thing to keep in mind is the slightly different specification that RadiantPERT has reguarding pressure and temperature. RadiantPERT is rated at 80 psi at 180 degrees. This 180 degrees is the maximum temperature water that can be run through RadiantPERT. No higher temperature is allowed under the specification. Other than that small difference, RadiantPERT is rated to the same specifications as RadiantPEX+.
What are the advantages of RadiantPERT?
First, RadiantPERT is more flexible than RadiantPEX+. This allows it to more easily achieve some installations RadiantPEX+ has problems with. For instance, in a snowmelt system with typical 9" spacing, 3/4" tubing usually requires a "lightbulb" at the end. If you used RadiantPERT in this situation, you would not need to worry about lightbulbs. The bend radius of 3/4" RadiantPERT is 4-3/8". This added flexibility will also allow easier installations in staple-up situations when trying to work around joist bays.
Another advantage to RadiantPERT is a greener manufacturing process then RadiantPEX+. During manufacture there are no chemicals needed to perform a crosslink, as is required for RadiantPEX+. In fact, RadiantPERT does not need crosslinking at all, which leads to faster production. Because crosslinking is not used, there is no need for a cure time, the tubing can be produced and send directly to QC and then packaging. No delay and no waiting. Production will be able to respond quicker to demand.
RadiantPERT is dimensionally the same as RadiantPEX+. This means that all of our RadiantPEX+ fittings and manifolds can be used with RadiantPERT. No need to learn new fittings or installation rules; it's all the same as the RadiantPEX+ you know.
Monday, October 29, 2012
RadiantWorks Professional - RadiantPERT
This update adds the new RadiantPERT product line to the program, with all pricing and part numbers. No other changes have been made at this time.
To install the update, just download the .exe file from the site, and it will install over the old version. Your settings and projects will not be erased or moved with the updated.
For more information regarding this or other Watts Radiant products, please visit the RadiantWorks page or call 800-276-2419.
Friday, October 26, 2012
The SunStat View
We have recently introduced a new thermostat for our electric floor warming products: the SunStat View, a touchscreen programmable thermostat!
Let's take a look at some of the features.
When you first turn on your SunStat View, it will step you through initial setup and programming with the startup tutorial. It will prompt you to select your language, set the time and date, and pick your temperature format (either °F or °C). This will allow you to quickly get your system up and running. Afterwards you may then customize your program to your needs.
This is a fully touchscreen thermostat, with the only buttons being to turn it on and test the GFCI. All the rest of the programming and usage is done through the touchscreen. Using a touchscreen allows the SunStat to present more information, in an easier form, to you. This streamlines programming, and makes it easy to check and change your settings.
The View is fully seven day programmable. You are able to select any individual day of the week and set specific times and temperatures for that day alone. This allows for very flexible programming. Do you work from home on Tuesday and Friday? Now you can set those days separately from the rest of the work week. Perhaps your kid has soccer on Thursday evening, and you want the system to come on two hours later than every other day. With this SunStat View, you can do that!
Wondering what time you need to program the View so that your floor is warm by 7am? Wonder no more! With the included SmartStat feature, your SunStat View will learn how long it takes to warm and adjust the start-up time accordingly. You just tell it the times you'd like your floor to be warm and it will do the rest for you.
If you do not need to program your SunStat, and would just like it to hold a certain temperature until you wish to adjust it, you can do that as well. You are able to either have it hold indefinitely, or some amount of days ranging from one to ninety-nine. If you are at home for a couple days, just set the hold for as long as you need, and afterward the SunStat will resume your normal programming.
If you are curious as to how much the SunStat View has been running, perhaps to estimate the electrical cost of the system, there is a usage monitor that will allow you to see the hours the floor has been heating. You can choose to view the current day, last seven days, or last thirty days.
On the technical side, the SunStat View is protected by a built-in GFCI. What this means is that if something happens to damage your heating element, the SunStat GFCI will instantly cut power to the floor, protecting the system from further damage, and you from shocks, just like a GFCI outlet. A nice side effect of having a GFCI built into the SunStat is that you will have no need for an expensive GFCI breaker.
The SunStat View is covered by a three year warranty. If something in the SunStat fails, it is able to be returned to the point of purchase and a new one received.
Wednesday, April 18, 2012
RadiantWorks Professional - April 2 2012 Pricing
The pricing in RadiantWorks has been updated to reflect the April 2nd price guide. The software now also includes all the current electric radiant products, such as ProMelt and SlabHeat.
To install the update, just download the .exe file from the site, and it will install over the old version. Your settings and projects will not be erased or moved with the updated.
For more information regarding this or other Watts Radiant products, please visit the RadiantWorks page or call 800-276-2419.
Wednesday, August 24, 2011
Installing SlabHeat
The spacing of the SlabHeat cable will help determine how much heated area can be covered by a single SlabHeat coil. SlabHeat can be installed on either 4” (15 W/sf) or 6” (10 W/sf) centers, depending on the amount of heat required for the area. A heat loss calculation is required to know which spacing is right for the project. If the SlabHeat system is to be used for floor warming only, installing the cable at 6” on center is sufficient.
Another consideration to take into account when designing a SlabHeat system is to know the available amperage. A 120 VAC system will pull twice the amps as a 240 VAC system. If amp capacity is a factor, it may be better designing for 240 VAC. Make sure the voltage supplied matches the voltage requirement of the SlabHeat cable. Failure to do so may result in either an over-heating or under-heating condition.
SlabHeat can be installed in either a new slab pour or over an existing slab with a concrete cap. For new concrete pours, just zip-tie the cable to the rewire/rebar and elevate to the middle of the slab. If installing over an existing slab, it will be necessary to install CableStrap™ to hold the SlabHeat cable in place.
When finished the only visible part to the system is the wall mounted SunStat thermostat.
A nice feature of the SlabHeat system is there is no annual maintenance required. Hydronic systems can require periodic cycling of the circulators to prevent the impellers from locking up during periods of non-use. Hydronic systems may also require fluid testing, treatment, and periodic system purges. SlabHeat systems are simple and easy.
Selecting the right product for the application is a breeze with SlabHeat. Since there are fewer parts needed to run a system, just thecable and control, ordering is easier than with a hydronic system. Just make sure to purchase the correct voltage, either 120 VAC or 240 VAC, and the correct number of thermostats or relays.
Controlling a SlabHeat system is also simple. Choose between two types of SunStat controls: programmable and non-programmable. Either one can be set up to respond to either a set floor or air temperature. SunStats are also dual voltage, meaning a single SunStat control can operate either a 120 VAC or 240 VAC system directly (one or the other, not both at the same time). This eliminates the need for cumbersome contactors, transformers, and complicated wiring as seen with other types of heating systems.
Whether heating a small sunroom or an entire warehouse, SlabHeat is the simple solution.
Christopher Campfield
Watts Radiant System Designer
Tuesday, August 23, 2011
Introducing SlabHeat
SlabHeat expands upon our successful electric floor warming product lines. Designed as a robust, job site resistant cable, SlabHeat is an electric radiant system installed directly in concrete. A combination of strength, durability, and simplicity lies at the heart of SlabHeat. Engineered to provide room heating as well as floor warming for a wide range of applications, SlabHeat is the perfect solution for even the toughest heating project.
Why choose SlabHeat over a traditional hydronic radiant system?
One of SlabHeat’s benefits is the lack of a complicated mechanical room. With SlabHeat there is no need for a heat source such as a boiler; the cable is the heat source! For new construction, as well as remodel, trying to add a dedicated heat source can create its own set of challenges. Hydronic heat sources require a dedicated space, venting, power, and fuel. Hard piping is also needed to circulate the heated water. SlabHeat has none of these obstacles. With SlabHeat all that is required is to run the cable across the space and connect to the SunStat® thermostat. Then, simply pull dedicated 120 VAC or 240 VAC power to the area to be heated. When using a SunStat thermostat, the rest is as easy as wiring a light switch.
Designing a SlabHeat system is much simpler than designing a typical hydronic radiant system. First, figure the gross square footage (wall to wall), then multiply that number by 90%. This square footage will be your heated area. The area to be heated will help determine if a 120 VAC or a 240 VAC system should be used. For a 120 VAC system this is approximately 115 square feet of heated floor area at 4” on center. For a 240 VAC system this is about 225 square feet of heated floor area at 4” on center. This is determined by the SunStat 15 amp limit. If larger areas are to be heated one of two things need to happen. Either add additional SunStat thermostats (one for each additional 115 or 225 square feet of heated area) or add SunStat Relays to the control strategy (one Relay for each additional 115 or 225 square foot of heated area).
Up Next: Installation...
Christopher Campfield
Watts Radiant System Designer
Monday, August 15, 2011
Basic Design of Hydronic Freezer Panel Systems
A typical freezer application consists of an industrial sized, permanent freezer above a soil or compacted base. One issue resulting from this application involves the ground directly below the freezer heaving due to the moisture in the soil freezing. This heaving can sacrifice the integrity of the structure and should be avoided or mitigated if possible.
Solution:
To remedy the freezing and subsequent heaving of the soil, circulate hot water through piping in the soil to maintain a temperature above freezing. The ideal solution is to heat the soil enough to prevent freezing, while not causing excessive heat to transfer to the freezer itself, reducing efficiency and increasing load on the mechanical systems.
Design:
The design for the necessary supply fluid temperature is extrapolated from ASHRAE heating load calculations. The output of the surface of the soil is dependent on the freezer design. Freezers with internal temperature ranges between 20 °F and 30 °F are designed with loads of 3 BTU/h-ft², the ambient temperature is set at 50 °F directly above the soil, with a maximum ground surface temperature of 55 °F. These assumptions yield a solution that results in the soil staying above freezing (32 °F), while limiting the surface

Results:
Empirical data shows that the resulting supply fluid temperatures within temperate climates range from 60 °F to 65 °F. With supply fluid temperatures that range close to the ground temperature, the back and edge losses from the soil are negligible. Dozens of these systems have been designed by Watts Radiant and are performing as expected for many years. The best results have been realized when combining intelligent controls that monitor ground temperatures with a heat source that harvests the waste heat produced from the freezer system. By doing this, a hydronic freeze protection system can be an attractive, simple solution that can be run with minimal cost to the owner.
-MDR