ᐅ Is a Gas Condensing Boiler a Practical Choice for New Single-Family Homes Under the 2016 Energy Saving Regulation?

Hello everyone,
we are planning to build a single-family house with underfloor heating (about 200 m² (2,150 sq ft) for 4 people). The energy standard will comply with the 2016 Energy Saving Ordinance, not a KfW standard. The walls will be made of thermal insulation bricks, 36.5 cm (14.4 inches) thick with a thermal conductivity (lambda) of 0.08, and triple glazing with a U-value of 0.8. The builder’s specifications include a gas condensing boiler (Vaillant ecoTecplus with a seasonal efficiency of 109%), a solar collector system (7.53 m² (81 sq ft)), and a combined storage tank (600/170 liters (158/45 gallons)). The builder recommends this setup. They advise against using a heat pump. However, I am now uncertain, because a friend strongly recommends installing a heat pump for underfloor heating. I would appreciate any answers, recommendations, and experiences.

Bob79 schrieb:
The construction company advises against a heat pump.

Why? Because of the initial costs?

Bob79 schrieb:
Now I'm unsure because a friend strongly recommends installing a heat pump with underfloor heating.

Again, the question: Why?

Both work well – gas and heat pumps.

P.S. I actually advise against both. You should definitely install a pellet heating system. Why? No idea. The other two don’t provide any reasons either. ;-)

We are currently building as well and have a solar system combined with a condensing gas boiler. However, we chose a smaller buffer tank of only 400 liters (105 gallons). This was recommended to us by the construction company because heating this smaller buffer as a compact system is much more efficient.

Gas is great. Your acquaintance has no idea. Heat pumps are more expensive overall and less flexible. They are also more costly to repair.

As the British say: technology should be simple, rugged, and reliable. Germans feel differently, especially those from Baden-Württemberg with their cuckoo clock genes—they prefer high-tech and extreme precision. But with the Brits, the helicopters are flying; ours are broken. Their ships are at sea; ours are in the shipyard. Their rifles shoot straight; ours shoot sideways. It’s the same with heating systems. I’m surrounded by air-to-water heat pumps, and there are always service vans from the companies tinkering with them because the electricity meter went berserk again or the house didn’t get warm. In our street, we have three gas boilers at numbers 3, 5, and 7. We never have any problems. Always warm, everything fine, everything works—simple, rugged, and reliable. That’s how it is in the real world. K.

Or did you possibly misunderstand your acquaintance? When using a heat pump, you should/must always install underfloor heating. The correct design of the entire system is important, which often does not happen.

Gas systems are more forgiving and can tolerate some design errors. Unfortunately, many heating engineers still work with the attitude “we’ve always done it this way.”