The greatest advance in home heating in the past few decades has to be the Open Direct System invented by Radiantec.
The Open Direct System uses a highly efficient condensing tank-style water heater that provides both radiant space heating and domestic hot water all in one unit cutting electricity requirements for those of us living off the power grid.
There are no heat exchangers (unless you want to subsidize with solar hot water), no poisonous antifreeze and no complicated controls. The same water that flows through your floor, goes through your water heater/boiler and comes out of your hot water tap.
Although this may sound strange, the pipe in your radiant heat system is no different from the pipe everywhere else in your home from the well to the taps.
The secret weapon of this system is the Polaris PG10 34-100-2 hot water. It truly is amazing with a real efficiency of 96%. It can heat water as fast as you can use it (5-6 gallons per minute), has a stainless steel storage tank holding 34 gallons and has standby losses of only 1%.
We love it and it has changed the way we heat our home and domestic hot water forever! We are saving about $400 CAD every year compared to burning wood.
Good places to buy the Polaris water heater/boiler and their parts:(as of August 23, 2015)
Amazon.com as low as $2941.44 USD for the 100,000 BTU 34 gallon model LP or NG (free shipping in the USA)
Radiantec $3299.00 for the 100,000 BTU 34 gallon model LP or NG (free shipping in the USA)
None – Will likely have to have one shipped to a community (from Amazon.com) just across the US border and bring it across yourself.
Central / South America
Far East / Asia Pacific
Vikrant Malhotra +91-9901011002 firstname.lastname@example.org
Contact U.S. Exports and Caribbean Sales at: email@example.com
The Polaris truly is our secret weapon for designing a super high-efficiency heating system. There is nothing like it! It produces 100,000 BTU, uses very little electricity and is as easy as connecting the gas supply, cold water in and cold water out.
This high-efficiency heating system is designed to work in a radiant heat application as the water traveling through your floor needs to be approximately the same temperature as the water going to your hot water tap. Radiant heat applications use warm water (100-140oF) to heat your floor as opposed to baseboard heaters and radiators that use much hotter water (160-190oF).
Here is how it works. When your zones (or a zone) need heat, the circulating pump will make hot water will flow from the water heater, through the check valve, through the pump, to the heating zone and back. This will heat your floor effectively and is pretty normal.If you look at the above drawing, you can follow the hot water from the top of the water heater through the check valve, through the circulating pump(s), through the heating zone (floor) and back to the water heater.
The real difference begins now…
When you open a hot water faucet, cold water enters the system from the cold water supply (well or municipal water system), goes through the heating zones, and enters the hot water tank. This forces hot water out of the top of the water heater, into your hot water piping and out the hot water tap.
In the above drawing, you can follow the hot water out the top of the water heater to the piping that leads to your hot water fixtures. The water is replaced by going from the cold water piping, through the circulating pump(s), through the zone and back to the hot water heater.
By the time this cold water reaches the hot water heater, it has already been preheated by the floor. In the heating season, the cold water will be warm by the time it reaches the hot water heater. This doesn’t really save money as you have already heated that water with your Polaris water heater/boiler.
Although this system works awesome in the winter, the real energy savings are in the summer as all the water entering your water heater has to go through the floor first.
The cold water leaves your well (or municipal system) goes through all the zones of your heating system and is warmed/pre-heated.
In the summer you can expect an increase of 10-20 degrees (for free) as the water flows through your floor.
This cold water cools your floor in the summer and provides some free air conditioning. By the way we have never had any condensation build-up on any concrete, wood, ceramic tile or click flooring that is being used to pre-heat the water.
The cold water will always flow through your floor first because of the check valve in the system.
ALL ZONES MUST BE OPEN ALL THE TIME!
If you close a zone (heating loop) the water in that loop will get stagnant and could become a health risk the next time it is opened and that water is allowed back into the system if you drink your hot water from the tap (which most folks don’t).
If you are planning on installing a solar water heating system, the open direct is the perfect companion. Look at the photo below. Every BTU collected with solar, will cut your fuel consumption. It is just a matter of plumbing in a new loop for the solar collectors if you live in a no freeze zone. If you live in the north, simply add a heat exchanger and antifreeze.
The Polaris/open direct system will work for hot water baseboard heating. Hot water baseboard requires higher temperatures and the Polaris will handle it but the Polaris is not as efficient at higher temperatures.
Another consideration is the resulting water temperature would be too high for bathing, showering or washing dishes.
Make sure you add a mixing valve to the water heading out to your taps if you use the open direct system for hot water baseboard or radiator heating systems.
A mixing valve is simply a device (that you connect your domestic hot water supply to fixtures and your cold water supply) that mixes cold water into your domestic hot water to lower the temperature to prevent burns at your taps or shower. They are adjustable to your preferred temperature and very reliable.
Good places to buy mixing valves:(as of August 23, 2015)
Amazon.com as low as $77.41 USD for a Taco 5004-C3 1″ Union-Sweat Mixing Valve ASSE 1017 (plus $9.38 shipping in the USA)
Radiantec $129.00 USD for the Honeywell AM102-US-1 Series 1″ Mixing Valves (plus $20.00 shipping in the USA)
Amazon.ca as low as $89.99 CAD for the Honeywell RC-AM101C-US-1 Mixing Valve (free shipping in Canada)
We will do our best to find worldwide suppliers of these mixing valves ASAP.
Advantages of Using the Polaris in an Open-Direct-System:
This system eliminates one of the biggest problems with radiant heating systems….air.
In most radiant heating systems, air gets trapped in the piping and pumps making the system work poorly. In the open-direct-system, air is forced out of the lines every time you open a hot water fixture as the full pressure of your pumping system is plenty to flush out any air. No need for air traps as in traditional radiant or base board systems.
Radiant heating systems work best at temperatures of 100-140 degrees F. The Polaris is designed to work the best at 100-140 degrees F. It is a match made in heaven.
If you try to use a standard boiler with radiant heat, you will always be operating your boiler at a lower temperature than it was designed to operate or use a mixing valve. Mixing valves are not efficient in this situation as you are paying money to heat your water only to cool it down with a mixing valve.
You only need to buy one hot water heater instead of a domestic water heater and boiler. This saves a lot of money and also saves standby losses. Every hot water heater you have will add another standby loss (through the sides and top) as well as an electrical load to your off-the-grid renewable energy system.
The open-direct-system is incredibly simple and code approved by the International Code Council (ICC). Email us at firstname.lastname@example.org if you would like the documentation supporting the open-direct-system.
You WILL save on your heating and hot water energy costs. Think about the summer. Your floor is warm and the sun is shining. Every time you open a hot water faucet, cold water is directed through the floor, preheated and sent to the water heater. We see a 20 degree temperature rise in the middle of the summer in our home. That is a 100% free rise in water temperature.
With a little extra plumbing, you can also direct all the cold water through your floor in the summer months. This can make a decent decrease in cooling costs and provide a much cooler home. We do this with our gardening watering system and it makes a huge difference in our bedrooms.
We also feed our toilets with the preheated water to stop sweating on those humid days. The possibilities are almost endless.
To make the open-direct-system work the best, the Polaris is the most reliable, inexpensive and well built heater available today. We installed our first one about 8 years ago. If we find a better unit, we will update this page immediately.