ᐅ How to Design an Efficient Heating System for a New Building?
Created on: 22 Jun 2024 13:13
T
Tzubaka
Hello homebuilding friends,
We are currently in the detailed planning phase of our house and need some quick support. The final goal is to build a KFW40 energy standard house.
I have tried to research extensively online but still haven't figured it out.
How exactly should a heating system be designed to be as efficient as possible? Like many new builds, we are planning a heat pump with underfloor heating. I have read that room thermostats should be omitted so the system can self-regulate. I have also read that a buffer tank is a bad idea.
I have read that the heat pump should operate at low temperatures to remain efficient. Additionally, I have read that a separate heat pump should be used for domestic hot water production. However, I have also come across many conflicting opinions.
Our heating technician wants to install a buffer tank with an electric heating element.
Right now, we are quite confused.
Could you help clear up the fog for me? What should an optimally designed heating system look like?
Thanks and best regards from a beginner builder
We are currently in the detailed planning phase of our house and need some quick support. The final goal is to build a KFW40 energy standard house.
I have tried to research extensively online but still haven't figured it out.
How exactly should a heating system be designed to be as efficient as possible? Like many new builds, we are planning a heat pump with underfloor heating. I have read that room thermostats should be omitted so the system can self-regulate. I have also read that a buffer tank is a bad idea.
I have read that the heat pump should operate at low temperatures to remain efficient. Additionally, I have read that a separate heat pump should be used for domestic hot water production. However, I have also come across many conflicting opinions.
Our heating technician wants to install a buffer tank with an electric heating element.
Right now, we are quite confused.
Could you help clear up the fog for me? What should an optimally designed heating system look like?
Thanks and best regards from a beginner builder
N
nordanney22 Jun 2024 17:29Tzubaka schrieb:
What options are there? Or what is the usual calculation per person?For example, a fresh water station that works like a tankless water heater. Or traditional hot water storage tanks that keep the potable water at the desired temperature. For a family with children, I would always recommend going directly for 300 liters (80 gallons). Smaller for couples or singles (200 liters (53 gallons)).Tzubaka schrieb:
I couldn’t edit anymore. I still don’t fully understand the heat pump part. How exactly is the water heated to, say, 60 degrees? Does this happen in the hot water tank then using electricity? Because the heat pump runs at around 30 degrees. Or am I thinking about this incorrectly?The heat pump heats the heating water to about 60 degrees (140°F); this water then does not circulate through the heating circuit but is diverted by the 3-way valve to heat the hot water storage tank and returns to the heat pump via the return line. Apart from that, in a single-family house you typically aim for around 50 degrees (122°F).
The setup could look like this roughly. In this case, it is a monoblock; with split systems, there is also an indoor unit which may already include the hot water tank—but basically, it works the same way.
nordanney schrieb:
1. Correct calculation of the heating load according to your requirements. For example, with a maximum supply temperature of 30°C (86°F) and your desired indoor temperature. nordanney schrieb:
The heat pump heats the heating water to, for example, 60°C (140°F), then the 3-way valve redirects the flow so it no longer circulates through the heating circuit but heats the domestic hot water storage tank, and returns through the return line to the heat pump. Do I understand this correctly? The heat pump operates at 30°C (86°F) when heating and temporarily at 50°C (122°F) if the domestic hot water drops below a certain level? And the 3-way valve is controlled by the heat pump? That’s the part I don’t fully understand yet.
S
stjoob_at25 Jun 2024 12:33Tzubaka schrieb:
Do I understand this correctly? The heat pump operates at 30°C (86°F) for heating and briefly at 50°C (122°F) when the domestic hot water drops below a certain level? And the 3-way valve is controlled by the heat pump? That’s the part I don’t fully understand yet. Exactly. And with most heat pumps, you can also set time blocks when the heat pump is allowed to produce domestic hot water and when it’s not. This is very useful for air/water heat pumps to schedule hot water production during periods when most electricity comes from the photovoltaic system and outdoor temperatures are higher.
It is also important that the heating circuit lengths are roughly the same. That makes the heating system more efficient, and don’t forget the wall heating in the bathroom.
N
nordanney25 Jun 2024 13:30Tzubaka schrieb:
Do I understand this correctly? The heat pump operates at 30°C (86°F) for heating and temporarily at 50°C (122°F) when the domestic hot water drops below a certain level? And the 3-way valve is controlled by the heat pump? That’s the part I don’t quite understand yet.Where did my reply go? I had written that the questions are phrased as statements that serve as the answer. Yes, the heat pump initially heats and then switches to a domestic hot water mode (when the temperature in the storage tank falls below a preset threshold). For this, it switches the valve and then heats the domestic hot water tank.
By the way, the heating technician might not want to install the system without a buffer tank due to manufacturer requirements. In that case, the buffer tank should be as small as possible and connected in series on the return line. This setup results in the least efficiency loss.
Hello,
my recommendation is in favor of a ground source heat pump. It should be somewhat more efficient than an air source heat pump.
However, this requires a ground borehole. If feasible, it might be worth considering. It operates just like an air source heat pump,
except you don’t need a separate outdoor unit.
my recommendation is in favor of a ground source heat pump. It should be somewhat more efficient than an air source heat pump.
However, this requires a ground borehole. If feasible, it might be worth considering. It operates just like an air source heat pump,
except you don’t need a separate outdoor unit.
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