Now that all of the Polygeyser systems have had the heat exchanger fully plumbed, we are working to complete the vortex based systems.  In this set of systems the heat exchanger is hung horizontally, rather than vertically.  Below is a picture of the first completed one.

One of the last tasks to be completed in the installation of the Indirect Heating System in our new Growout Greenhouse is some plumbing.  We will be using PVC plumbing to take water from the tanks and send it into the heat exchanger.  Once inside the heat exchanger the water will be heated indirectly be the hot water filled tubes.  The tank water will then flow back into the tank.  These are two of the completed systems.

Refering back to the new heating system we have installed in our Growout Greenhouse (Part 1 and Part 2), we are going to send this warm water to an adjacent greenhouse.  In the front of our Nisai Greenhouse, we have the BETN koi and our other very high quality nisai,  which you can view in our online catalog.  To provide these koi with the optimal growing conditions, we are not only heating the air but also the water.  We have run insulated copper plumbing underground from the Growout Greenhouse to the Nisai Greenhouse.  There are lines for both the feed and the return.  The one major difference however, is that the heat exchanger for the Nisai Greenhouse is underwater in the tank, whereas the heat exchanger in the Growout Greenhouse is external to the tank.

Whereas the last post described how we are now heating the water in our Grow-out Greenhouse, this post will describe how we are heating the air.  The primary purpose of also heating the air is to keep the air about two degrees warmer than the water so that we won’t have condensation continually forming on the inside roof of the greenhouse.  In order to accomplish this we will utilize a similar method as to how we are heating the water.  Hot water produced from our boilers will be carried through copper plumbing and up to a Modine heater suspended from a metal greenhouse bow.  The hot water will flow through the heater and a fan will blow the warm air across the greenhouse.

In an earlier post, I started to discuss the filtration aspect of our new Grow-out Greenhouse.  This post will begin to discuss our new indirect heating system that is currently being installed in the greenhouse.  The purpose of the Grow-out Greenhouse is to increase the length and mass of our smaller high-grade koi.

The majority of our other greenhouses have heating systems where propane is utilized to heat the air and subsequently heat the water.  There are many inherent problems with this system, the largest one being inefficiency.  Since heat rises, much of the heat escapes through the roof.  Also, when the heat is raised to 78 degrees the water only reaches 65-66 degrees.  At this temperature koi will not put on the size we are trying to achieve and we are not able to feed them a high protein food.

Our new indirect heating system utilizes six heat exchangers (one per system) and two boilers.  Each boiler is 150,000 BTU which is more efficient than one 300,000 BTU boiler because having two allows for stage firing.  The boilers are powered by propane to heat water.  This water travels through copper piping into the greenhouse.  We chose copper because the spanning between brackets is 5 feet, and copper won’t bow, buckle, or degrade in the sun.  The water in the copper will never come in contact with the koi (copper is toxic to koi).  The heated water is brought into a heat exchanger.  The heat exchanger is filled with many tubes, which are filled with the heated water.  The pond water also enters the heat exchanger, but it surrounds the outside of the tubes.  Through this indirect contact, the pond water is heated and brought back into the ponds through PVC plumbing.  In the picture of the heat exchanger you will not see the PVC plumbing, as that is one of the jobs to be done this week.

This system of indirect heating gets the water much warmer than it would if we were to heat the air.  Also, it provides a more consistent water temperature.  Each system will also have its own thermostat so that it can adjust the heat automatically should one system become cooler, such as during a water change.  We will now be able to heat the water to our ideal 76-78 degrees.

While the initial investment to setup this system is more expensive, the cost to operate it will be considerably less expensive due to its efficiency.

Photo of a vertically installed heat exchanger (PVC portion that brings the pond water into and out of the heat exchanger is not yet plumbed).  This is the installation for the “Polygeyser” systems.

Photo of heat exchanger

Photo of horizontally installed heat exchanger (PVC portion that brings pond water into and out of the heat exchanger still to be plumbed).  This is the installation setup for the “vortex” systems.

Photo of the boiler room.  They are setup in a shed located outside of the greenhouse.