ᐅ Air-to-water heat pump without buffer tank | Heating contractor refers to building energy regulation requirement

Hello everyone,

I have used the search function but couldn't find any information on my issue.

Our current building project is still in the planning phase. We are constructing a single-family home (KFW 55 EE) through a general contractor. Everything is arranged so far, the KfW funding is approved and confirmed. So far, so good! The trades are currently being discussed, and I am in a dispute with the heating engineer commissioned by the general contractor.

Content of the scope of work:
Air-to-water heat pump with electronic radiator thermostats (ERT) and buffer tank, etc.

My execution request:
An air-to-water heat pump without ERTs and buffer tank, as I want to use the “self-regulating effect” (calculation of the hydraulic balancing or the minimum/total volume flow to avoid using a buffer tank and bypass valve in the hydraulic system, in order to heat the house more energy efficiently).

Also, the ERTs in the individual rooms should not be connected or only installed as visual elements.

The heating engineer says that, due to the current applicable energy saving regulations, he is not allowed to install the air-to-water heat pump without a buffer tank. If the inspection by the energy consultant has yet to be completed, it would not be approved because of the missing equipment (buffer tank + ERTs). He insists on a buffer tank!

What options do I have as the client to still receive an air-to-water heat pump without a buffer tank and ERTs? Is there actually an inspection by the energy consultant? Is this common?

Maybe the community here has some tips or possibly even a solution? Thanks in advance for any help.

Best regards,
Tom

Stravanzer schrieb:

The heating technician claims that, based on the currently valid energy saving regulations, he is not allowed to install the air-to-water heat pump without a buffer tank.

Just ask him exactly where it says that. After some hesitation, the technician will probably say, "I can’t find it right now" (and indeed, he won’t find it, because this requirement doesn’t exist). Buffer tanks are actually rarely installed since they are mostly unnecessary or reduce efficiency.

Expansion vessels (ERRs) are mandatory—you would need to apply for an explicit exemption to omit them. Alternatively, you could remove them after commissioning. The engineering firm Heckmann, which planned my heating system, offers a site-specific exemption letter for €100 if you contract them for the heating design and heat load calculation. Any planner can provide such a letter if they are willing to do so.

Benutzer200 schrieb:

Just ask him where exactly it says that. After some hesitation, the heating engineer will probably say "I can’t find that right now" (and he won’t be able to find it, because there is no such requirement). Buffer tanks are actually rarely installed because they usually don’t make sense or reduce efficiency.

ERRs (Energy Saving Regulations) are mandatory – you would need to apply for an explicit exemption if you want to avoid them. Alternatively, you can remove them after commissioning. For example, the engineering firm Heckmann, which planned my heating system, offers a project-specific exemption letter for €100 if you order the heating design/heating load calculation from them. Any planner can provide this if they are willing to do so.

Thank you for your response.
So far, I haven’t found anything regarding a mandatory buffer tank for the 2016 Energy Saving Ordinance, but I want to be on the safe side and, if possible, present the facts to the heating engineer.

I have already commissioned the engineering firm you mentioned for the complete calculation, including the option for exemption from the ERR.
Do you have any experience with how long it usually takes for the engineering firm to deliver the data? Days, weeks?

Best regards

Stravanzer schrieb:

I commissioned the energy consultant you mentioned for the complete calculation, including the option for exemption from the energy-saving regulation (ERR).
Do you have any experience with how long it takes for the data from the energy consultant to become available? Days, weeks?

14 days after submitting the required documents. In between, there were several follow-up questions because I had commissioned a two-family house with two heat pumps and also the design for underfloor heating in apartment 1 and radiators in apartment 2. If everything had been complete, it probably would have taken 3–4 days.

If I remember correctly, it happened to me on the third day, which was a Saturday or Sunday (!).

Stravanzer schrieb:

about a developer.

Stravanzer schrieb:

to me as the owner of the construction project

You are not the owner of the construction project. You are the buyer.