ᐅ Buffer tank? Combi tank? Domestic hot water storage tank?
Created on: 13 Aug 2015 08:58
R
Regina_Matthias
Hello dear forum,
For our single-family house, we have decided on a 15 kW pellet heating system. There is currently no solar support planned. Now the heating installer asked us whether we would prefer a regular buffer tank, a combined tank, or a hygienic tank. The additional cost for the buffer tank (Cosmos buffer tank CPS 500) with soft foam insulation compared to a hygienic tank of 800 liters (210 gallons) with an internal stainless steel domestic hot water heater (flow-through principle) and 90mm (3.5 inches) rigid foam insulation is 490.00 EUR plus VAT.
We have no offer yet for a combined tank.
What exactly are the differences between these systems?
What experiences do you have with the three options?
How does the type of insulation (soft foam, rigid foam, EPP, EPS) affect ongoing costs (fuel, electricity)?
I appreciate any advice.
For our single-family house, we have decided on a 15 kW pellet heating system. There is currently no solar support planned. Now the heating installer asked us whether we would prefer a regular buffer tank, a combined tank, or a hygienic tank. The additional cost for the buffer tank (Cosmos buffer tank CPS 500) with soft foam insulation compared to a hygienic tank of 800 liters (210 gallons) with an internal stainless steel domestic hot water heater (flow-through principle) and 90mm (3.5 inches) rigid foam insulation is 490.00 EUR plus VAT.
We have no offer yet for a combined tank.
What exactly are the differences between these systems?
What experiences do you have with the three options?
How does the type of insulation (soft foam, rigid foam, EPP, EPS) affect ongoing costs (fuel, electricity)?
I appreciate any advice.
We also considered using a water-bearing wood stove (including pellet models) instead of a pellet boiler. The main and ultimately decisive difference—besides the option to choose a significantly lower kW output—was that the BAFA subsidy for option 2 is only half (€1400) compared to the actual boiler (€2900), because only the boiler setup, including the buffer tank, is eligible for funding, not the stove. Since the boiler itself cost €2900 and was essentially fully covered by the BAFA subsidy, and our renovation budget was extremely tight anyway, we went with the boiler.
In the end, the boiler is installed in the same location as the stove was before (in the middle of the house in the living area, since that’s where the chimney is). Moving it elsewhere would have involved massive effort. However, the boiler looks quite decent; it only lacks a window to see the fire. Otherwise, it’s not more unattractive than a standard radiator—which we deliberately avoided by opting for underfloor heating.
In the end, the boiler is installed in the same location as the stove was before (in the middle of the house in the living area, since that’s where the chimney is). Moving it elsewhere would have involved massive effort. However, the boiler looks quite decent; it only lacks a window to see the fire. Otherwise, it’s not more unattractive than a standard radiator—which we deliberately avoided by opting for underfloor heating.