The development of the OptiSun hot water boiler started because of the need for changing old systems.
In northern conditions the problem of solar heat systems has so far been the disposal of excess heat in summer. It can be difficult and expensive. Usually it has led to oversized capacitor volume, which increases the costs, or too small collecting area. In both cases the sun heat part remains small and the stored heat transfer fluid isn’t hot enough to produce warm water in autumn, winter and spring.
Because the OptiSun solar collector can control the temperature of the hot water boiler, the planning of the sun and exhaust air heating system OptiSun’s boiler could be started with a clean slate. The result was the OptiSun hot water boiler, where you can get, as the name also tells you, hot water all over the year. At the same time the using of the collector and heat pump as well as the heat transfer are optimized. In addition, the heat losses are minimalized.
The designing of the OptiSun hot water boiler
It was clear that the boiler planning will no more be based on the limits of sun heat or any other heat production system, but based on the structure and heat demand of the property.
The best temperature deposition was achieved with the structure as high as the whole block house. A high structure is the most natural also because underground cold water flows to the bottom of the boiler and pipes come there from the solar collector located on the roof of the house.
There are also cold and hot water pipes by the boiler, so in connection with pipe renovation they are easy to lead to each staircase and each floor.
The system has been planned also for renovation targets with no large spaces or doors for big traditional boilers. However, there is space in many old houses for a pipe-like high boiler built of modules, for example in staircase, masoned flues which are out of order, or rubbish chute.
The sizing of the OptiSun hot water boiler
The principle of sizing of the OptiSun hot water boiler’s volume is to store there that amount of heat which you can use to control the weekly changes of need for heat. At the same time the diurnal of sun heat production will be compensated and the use of the exhaust air heat pump will be optimized as independent of consumption.
The structure of the OptiSun hot water boiler
The OptiSun hot water boiler is a block house high pipe-like tank full of heat transfer fluid which flows through the solar collector and exhaust air heat pump. Usually the heat transfer fluid is regular tap water.
The tank has been built of one floor high isolated steel tube modules which are put one on the other and connected by compression flange connections. The foundation of the tank is a welded steel stand.
It’s also possible to build the OptiSun hot water boiler of one piece and install it outside to the wall on the cast concrete foundation. That way the boiler is cheap and the installation is quick. The issue is the need for thicker insulation due to colder temperature outside.
There are regular heat exchanger coils made of one or more copper comb coils inside the tank, bottom and top, for producing of warm water.
There are interfaces for room heating water in the heat distribution system in accordance with wanted temperature, near the bottom and top of the boiler.
The structural and functional safety of the OptiSun hot water boiler
The requirements of the EU Pressure Equipment Directive have been regarded in the designing of the OptiSun hot water boiler. All the boiler modules are planned so that how high the block house might be, the boiler will always be like the requirements tell.
The connecting of the OptiSun hot water boiler to property’s heating system
The OptiSun hot water boiler will be connected to the water and room heating system like any regular warm water boilers.
The function on the OptiSun hot water boiler
You can optimize the using of the collector and heat pump with the OptiSun hot water boiler by stopping the heat pump when enough free sun heat is available. If there is too much sun heat and the boiler is about to boil, the solar collector stays or turns into the shadows. When the sun heat alone is not enough to fulfill the heat demand, the heat pump will be started. You can load heat to the boiler beforehand, so there will be enough heat also during consumption peaks.
You heat cold water with the nethermost coil and make sure both the solar collector and the exhaust air heat pump get the heat transfer fluid as cold as possible. So we can be sure that the solar collector and the exhaust air heat pump are working in the best possible efficiency.
You superheat warm water with the coil on the top of the boiler. Thanks to the pipe-like structure, the space on the top part of the boiler is small and from the solar collector coming heat transfer fluid which is as hot as possible, will be led to it’s uppermost point. This structure ensures, that the water is always hot enough.
The heat losses of the boiler will be minimized by isolating it well or locating it to a warm place, for example the middle gap of the staircase.