Hybrid Hydronic Heating/Cooling Systems

The hybrid hydronic heating/cooling system consists of hydronic floors and hydronic fan coils. The system eliminates the main disadvantage of forced air system, which is dried air. It also alleviates the main disadvantage of existing hydronic floor heating/cooling, which is slow heating/cooling. Gentle breeze from hydronic fan coils fast heat or cool your dwelling space. Hydronic floor keeps the temperature as much as constant. The clean floor keeps your beloved ones from carpet-related allergies.

Pros of forced air heating/cooling

-. Used to

-. Fast heating/cooling

Cons of forced air heating/cooling

-. Need carpet, but still cold feet

-. Dried hot air, coughing and asthma

-. Not energy saving, or well fit with air-to-water heat pumps

Pros of hybrid hydronic heating/cooling

-. Clean floor and allergy free

-. Gentle breeze from hydronic fan coils

-. No dried air or cold feet

-. Fast heating/cooling by fan coils

-. Energy saving by floor heating/cooling

Cons of hybrid hydronic heating/cooling

-. Technologies not yet well established

-. Condensation issue in cooling mode

-. Not many certified installers

We, Namu Hydronic Systems, have researched and developed hybrid hydronic heating/cooling systems. It is an innovative heating/cooling systems that well fit with air-to-water heat pump applications. Our hybrid hydronic systems yield a cozy, allergy-free, and energy-saving dwelling space.

Why Hydronic Radiant Heating System

The hydronic radiant heating systems are the most efficient and safe way of transferring heat. The heat is carried by flow of how water from heat sources, such as gas boilers and air-to-water heat pumps. The higher specific heat value the material is, the more heat energy it carries. Below specific heat of some materials are listed;

-. Air: 1.005 kJ/kg-K

-. Water: 4.184 kJ/kg-K

-. Aluminum: 0.9 kJ/kg-K

-. Copper: 0.385 kJ/kg-K

The traditional way of forced air heating has an innated disadvantage, which is it’s specific heat value. Traditional ways of HVAC are no longer fit in the new paradigm that is focused on energy saving. Governments have started banning on gas boilers. Air-to-water heat pumps, in the most efficient way and without emitting carbon, produce hot water. If the home owners think why federal, state, local governments are willing to offer rebates for installing air-to-water heat pumps, the answer is very clear. Think why there are hydronic radiant heating systems in the most air-to-water heat pump applications.

Advantages of Radiant Floor Heating Systems

Radiant floor heating system has a number of advantages over traditional forced-air systems. It is more efficient than baseboard heating and usually more efficient than forced-air heating because it eliminates duct losses. People with allergies often prefer radiant heating because it doesn’t distribute allergens like forced-air systems. Hydronic systems use little electricity, a benefit for homes off the power grid in area with high electricity prices. Hydronic systems can use a wide variety of energy sources to heat the liquid(usually water), including standard gas- or oil-fired boilers, wood-fired boilers, solar water heaters, or a combination of these sources. Fore more info., please visit U.S. Energy Department.

  • Occupant Favorable, not Ceiling Favorable

  • Energy Saver

  • Allergy Free

Types of Radiant Heating Systems

There are two types of radiant floor heating systems that residential home could easily apply to:

  • Electric Radiant Floor Heating

  • Hydronic Radiant Floor Heating

Electric radiant floor heating systems typically consist of electric heating cable into the floors. Systems that feature electrical matting mounted on the subfloor below a floor covering such as tile are also available. Because of the relatively high cost of electricity, electric radiant floors are usually only cost-effective if they include a significant thermal mass such as a thick concrete floor and your electric utility company offers time-of-use rate.

Hydronic radiant floor heating systems use hot water to warm the floor. Heated water, generated by your boiler system, circulates through piping installed in the floor throughout a building or home. This piping is also known as PEX or crossed-linked polyethylene. This hydronic floor heating is relatively easy to control individual room temparature.

The Hoya ondol system has been developed to bring back the traditional Korean ondol floors to modern residential homes. Hoya ondol shall deliver a cozy dwelling space to your home. The elvan stone panels are developed by a co-research with KIST to adopt the traditional Korean ondol to a modern dwelling space.

Hoya ondol panels are made from eco-friendly carbon composite with elvan stone powder, and could be reused. It also reduces your energy bill up to 30%. Hoya’s elvan stone panels radiate far infrared lays that boost your health.

Hoya Ondol Component Layers

Specifications of Hoya Ondol Components

Namu Housing Product Line

Single Room/Backyard Office/Garage

Whole House Remodeling

Elvan Stone Beds

Specialized Boilers & Thermoregulators for Namu Hydronic Heating System

Navien Tankless Combi Boilers

Navien’s NCB-H condensing combi boilers offer industry leading DHW features including the highest maximum BTU/h for DHW (210,000), highest flow rate of 5.4 GPM at 70° rise and a DHW turndown ratio of 15:1.

  • Highest DHW flow rate @ 70°F rise...
    up to 5.4 GPM

  • Highest number of BTU sizes for
    the North American residential
    combi-boiler market

  • Highest residential combi DHW TDR...

  • 15:1 for all models

  • Highest residential combi heating
    TDR... up to 11:1

  • Highest number of built-in zone controls for valves or pumps... up to three

  • Highest full lineup 2" PVC venting lengths... up to 65 feet

  • Highest number of cascade capable
    units with NPE tankless water heaters... up to 15

  • High altitude certification... up to 10,100 feet (NG or LP)

  • Lowest minimum fire BTU for residential combi-boilers... as low as 10,700

Navien NHB condensing heating boiler is the most advanced condensing fire tube boilers in the industry, and now with more heating capacity for any size home.

• Good for small & large homes

• Low noise

• Up to 15:1 turndown ratio

• Built-in capability for multiple zones

• Wi-Fi compatible

• Expandable via cascading technology

Dong Il Brazing Electric Hot Water Circulators

To serve small spaces such as a single room and a backyard office, we have determinedly explored for electric boilers. Through cooperations with a S. Korean company, we could eventually acquire two types of electric boilers that meet our needs for small hydronic heating systems. It ideally produce sufficient hot water to our elvan stone panels, and eliminates need for electric transformers. These are the two types of electric boilers:

  • DI-M 015K - 110 Volt, 1.5 kw/h, 1,290 kcal/h, 10.0 square meters (107 sf), W385mm, D130mm, H400mm, W5.7kg

  • DI-M 030K - 220 Volt, 3.0 kw/h, 2,590 kcal/h, 20.0 square meters (214 sf), W385mm, D130mm, H400mm, W5.7kg

OnSystem Thermoregulators

OnSystem has researched and developed themoregulator system that shall optimized energy efficiency in hydronic heating system. Unlike other systems, it checks temperature of return water to optimize the boiler running. It consists of:

  • Thermoregulator

  • Return water censor.

  • Actuator

  • Room temperature controller

Installation of Hoya Hydronic Heating System for a Whole House

Step 1: Preparation for installation

  • Plan the best layout for the floor heating pipe

  • Hoya’s elvan stone panels are rather firm material. Therefore, fairly even surface is required.

  • Clean the floor to secure even surface.

  • Lay the insulation sheets. Two layers of insulation is strongly recommended for a better heating result.

  • Tightly tape the overlapped lines to trap cold air under the floor.

Step 3: Install the PEX(PE-RT) Pipe

  • Roll out the pipe pushing it into the channels of the bottom panels

  • Unroll the pipe hand over hand to avoid twisting or kinks

  • Do not kink the pipe by trying to make a very tight turn

  • The pipe should run start and finish at the manifold, by fitting the manifold in place before laying the pipe. Allow sufficient pipe for cutting and fitting at a later stage

Step 05: Connect PEX Pipes and Flow Controllers to Distributor, and Connect the Distributor to the Boiler

  • Connect PEX(16mm) pipes to the distributor(distribution manifold) using coupling sockets

  • Install actuators onto the coupling sockets.

  • Install thermal sensor probes into the installed actuators

  • Connect the flow manifold to hot water outlet of the boiler

  • Connect the return manifold to returning inlet of the boiler.

※ Note: We use DK Navien electric boilers. This step must be done be a licensed plumber.

Step 7: Install Hoya Elvan Stone Floor

This step is basically finalizing the floor surface. It is not necessary to put finished floors, if it is rough area, such as an office. Thermal conductivity is the key factor of hydronic floor heating. Other floor materials have thermal insulation layer. That’s why Hoya elvan stone floors are developed, even there so many finished floor materials available. Hoya elvan stone floors maximize thermal conduction to the floor surface.

Step 2: Install the bottom panels

  • Start laying the panels. Lay panels side by side along the edge of a wall in the most appropriate orientation.

  • Continue to lay panels across the rest of the floor.

※ Note: Take care to align panels accurately.

Step 4: Install the top panels of HOYA ONDOL

  • Snap-fit the top and bottom panels

  • Use the rubber mallet hammer for easy work

  • Please make sure all the male panel clips of the top panels are securely positioned into the female clips of the bottom panels.

  • We strongly recommend to use Hoya firm panels on all area working on to create evenly firm floor surface

Step 06: Configuration of Thermoregulator and Room Temperature Controller

Especially this installation step requires comprehensive understanding of OnSystem’s thermoregulators and general boiler knowledges. it should be done by a highly skilled contractor. It, however, would be easy and automatic, if no error detected.

  • Discharge air in the pipes and the boiler. DK Navien boilers have the function of discharging air. However, we strongly recommend to discharge air in the system.

  • Initialize the thermoregulator and the boiler. It would take about 20 minutes without any system errors detected. It would take about 20 minutes to handle an error with one actuator. In many cases, errors are related with thermal sensor probes. Please make sure the thermal sensor probes are installed securely.

※ Note: We use OnSystem’s room temperature controller and thermoregulator units. With DK Navien electric boilers, it delivers individual room temperature controlling, and achieves up to 30% energy reduction.