ᐅ Planning Heating and Ventilation Systems for a KfW 40 Plus Single-Family Home

Created on: 30 Sep 2020 09:56
D
DaSch17
Hello everyone,

We have a planning meeting with the heating and ventilation engineer scheduled for October/November.

In preparation, I have been wondering what I should pay special attention to and what is important. I hope to receive some valuable planning tips for this very important trade.

Brief key information about the planned new build:
- 2 full floors, clear structural height per floor 2.85 m (9 ft 4 in)
- KfW 40 Plus standard
- Heated living area approximately 190 m² (2045 ft²)
- Additional heat source: fireplace in the living/dining/kitchen area about 60 m² (645 ft²)
- Floor plan: see post #254 in https://www.hausbau-forum.de/threads/efh-neubauvorhaben-von-tag-1-an-und-die-planung-beginnt.33766/page-43

The following information and requirements (in addition to the planning documents) have already been sent to the heating/ventilation engineer:
Heating technology:
- Split air-to-water heat pump or ground-source (brine-to-water) heat pump
- Eligible for BAFA funding
- Underfloor heating in all rooms (except garage with storage room) with a target temperature of 21-22°C (70-72°F) in all rooms and 22-23°C (72-73°F) in the bathrooms
- Smart grid compatible (for using photovoltaic electricity)
- Cooling function if possible
- Hot water storage tank sized for a household of 4 persons

Controlled residential ventilation:
- Cooling function or summer bypass

What should I pay special attention to? What tips do you have?
DaSch1723 Nov 2020 13:37
Hello everyone,

Attached is the quote from the heating specialist for the ventilation system, heating, and rough-in plumbing.

From your perspective, is this generally acceptable? Does the price-to-performance ratio seem reasonable?
According to the heating specialist, the final sizing of the ventilation system still needs to be completed.

At first glance, it seems very affordable. So, for ventilation, heating, and rough-in installation a total of 39,500 EUR minus approximately 11,000 EUR BAfA funding.
For the sanitary fixtures, including installation, we have allocated an additional budget of 18,000 EUR.

Ventilation system

Product list: Vaillant recoVAIR VAR 360/4 central ventilation unit with EC fan motors, 3,442.50 €


Invoice/quotation page with items, quantities, descriptions, and prices in euros.


Invoice item: sensoCOMFORT VRC 720 heating controller, eBUS interface, price 538.65 €


Receipt with two items, total 3,962.25 €, heating technology (eBUS) and Vaillant VR 921.


Image showing a quotation/invoice page with item, description, and extensive text blocks.


Quotation/invoice with photovoltaic system, eBUS interface, controller, installation work, total price.
DaSch1723 Nov 2020 13:41
Heating:


Invoice items: heat pump and accessories – Vaillant 4.32 aroTHERM Plus VWL 75/6 VIH RW 300


Product list of a heating system with PV-ready energy management, connections, and pricing details.


Price and item list of a heating package Vaillant aroTHERM plus including total price €8,316.50


Datasheet of a heating heat pump with technical performance parameters and connections


Invoice with items, quantities, descriptions, and prices of Vaillant heating components.


Photo of an invoice table with items, quantities, descriptions, and prices.



Detailed invoice with items such as lifting station, pipes and accessories, quantities, and prices.


Invoice overview with items, quantities, prices for insulation/piping material and underfloor heating


Price overview of a construction offer: table with items, quantities, descriptions, and prices.


Price quotation as a table with items, unit and total prices, and final sum.
DaSch1723 Nov 2020 13:44
Sanitary Rough-In Installation:


Price overview of wastewater installation: Polo-Kal XS pipes DN 50, 75, 90, 110 x 1000 mm (3, 3, 4, 4 inches x 3 ft) with sockets.


Price overview: Polo-Kal XS components (transition pipes, elbows, branches) with quantities and prices


Wastewater installation invoice: Itemized list with quantities and prices.


DRINKING WATER INSTALLATION: Table with items, quantities, descriptions, and prices


Clear invoice table with items, quantities, prices, and total amount.
Mycraft23 Nov 2020 14:46
I would say that everything looks quite okay. The tank should be checked regarding where and how exactly it will be installed. It is important that it is used only for potable/domestic water and not also for heating.
K1300S23 Nov 2020 19:49
The uniSTOR is designed only for domestic hot water, which is fine. However, I’m a bit surprised by the heating capacity of the offered heat generators and the fact that two devices with different outputs are being offered. The heating engineer should know which one fits best.

I would also recommend installing an external current anode for the tank. It’s inexpensive, but gives you peace of mind forever.
Tolentino23 Nov 2020 20:04
There is still a compact buffer tank listed under the heat pump/Unistor sets and not as an alternative option...