ᐅ Experiences with a masonry heater combined with an air-to-water heat pump?

Energieverbrat schrieb:

Hi, that’s not a good idea.
A water-bearing stove means that only a small portion, less than 30%, of the heat goes into the water. The lower the stove temperature, the less the water will be heated proportionally. You don’t want to sweat in the living room and have lukewarm water at the same time.

We have a Panasonic monoblock 9 kW (9,000 watts) air-to-water heat pump with an 8 kW (8,000 watts) fireplace insert in the living room. The fireplace insert serves as a backup to heat the living room in case the heat pump breaks down. There is an electric heating element in the hot water storage tank as a backup. Otherwise, the heat pump supplies water and underfloor heating at the lowest temperatures because that is the most comfortable.

May I ask what type of fireplace insert you have?

A tiled stove usually emits only about 20–30% of the energy through the glass. This is a significant difference compared to a fireplace, which is one reason why a tiled stove cannot have as much glass. Depending on the type of tiled stove you have, the remaining 60–70% of the heat is transferred to the hot water circuit. Additionally, the bricks provide thermal storage capacity.

A fireplace is NOT the same as a tiled stove.

cryptoki schrieb:

May I ask which stove insert you have?

A tiled stove usually only releases about 20-30% of the energy through the glass. This is a significant difference compared to a fireplace insert, which is why a tiled stove generally cannot have as many viewing windows. Depending on the type of tiled stove you have, the remaining 60-70% of the heat is transferred to the domestic hot water circuit. Additionally, there is heat storage capacity in the bricks.

A fireplace insert is NOT the same as a tiled stove.

I have a Haas & Sohn Komfort IV 8 kW (8,000 BTU). I installed it myself and clad it with Knauf red lime boards made of perlite. The insert cost about 1,200€ (euros), and the ventilation grille, inspection door for the temperature sensor, underpressure monitor, special mesh, boards, and plaster were about 1,000€ (euros).

The insert is just for fun and not comparable to a heat pump.

Attached is a photo.

Thank you. I am looking for experiences with a real tiled stove, preferably combined with a heat storage mass and, as a finishing touch, a Moritz damper, also water-heated 😉

cryptoki schrieb:

Thanks. I’m looking for experiences with a real tiled stove, ideally combined with thermal mass and, as a final touch, a Moritz damper and also water-circulated 😉

Topic thermal mass. The wall behind the stove insert is 24cm (9.5 inches) of sand-lime brick, so there is a good amount of thermal mass present. However, insulation always has to be installed between the stove and the wall due to requirements from the chimney inspector.

I am convinced there is no difference between a stove insert and a tiled stove. In both cases, the living room overheats to heat the water. The tiles of the tiled stove do take longer to warm up, but once heated, you basically have a small sun in your living room.

In new builds, a tiled stove is really challenging. Have your heating load calculated—you will realize that trying to heat a 2 kW living room with a tiled stove becomes uncomfortable.

Energieverbrat schrieb:

I am convinced there is no difference between a wood stove and a tiled stove.

These are worlds apart, especially when it comes to the chimney flues. A crucial aspect is also how the heat exchanger is designed and how easy it is to clean. Dirt buildup can quickly cause the efficiency to plummet.

Energieverbrat schrieb:

In new construction, a tiled stove is really challenging. Have your heating load calculated, and you will find it uncomfortable to heat a 2kW living room with a tiled stove.

That’s exactly what happens with a wood stove when 80% of your 8kW is released directly into the room. Then you suddenly have 6.4kW of direct heat. Time to get the sauna towels out. A tiled stove with properly designed chimney flues stores the generated energy and releases it over several hours. A properly built tiled stove is not refueled every 30 or 60 minutes; instead, it burns efficiently over 2 to 4 hours. The exhaust gas temperature going through the chimney is also significantly lower.

cryptoki schrieb:

Thanks. A tiled stove is significantly more efficient than a standard fireplace, and you yourself say that your neighbor uses it as the primary heat source. The costs can also be very low.

My concern is not just about assembling something quickly and calling it done, but about smart combinations. When I heat up the stove, the air-to-water heat pump shouldn’t have to keep running. It’s clear that enough heat will come from the stove over the next 2–4 hours. The stove and the air-to-water heat pump should be able to communicate with each other…

I can’t imagine that this works. An air-to-water heat pump is not like a central heating system. You turn it down to zero, and it’s off. It takes hours for it to reach zero.