Moving into an ecohome - what to check?

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jamiecreek

(@jamiecreek)

New Member Member

Joined: 4 years ago

Posts: 1

Topic starter 29/08/2021 8:18 pm

Hi,

We're in the process of buying an ecohome and it's all a bit new to us. Looking for advice on things we really should get checked, buyer beware etc.

It was newly built around 10 years ago. It's a 3 storey detached house, heated by an air source heat pump, a Daikan erhq016, with a solar panel installation on the south facing roof and solar batteries as well. Ground and first floor have underfloor heating, top floor has radiators.

There's even a rainwater harvesting system under the garden.

We assume a regular RICS building survey is not going to check important things about the efficiency of the house's setup.

Anything we should definitely get investigated, or types of specialist survey or checks we should have carried out?

Thanks!

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Derek M

(@derek-m)

Illustrious Member Member

Joined: 5 years ago

Posts: 4427

30/08/2021 7:51 pm

Hi Jamie,

Welcome to the forum, though things seem a little quiet at the moment.

Let me first of all state that I am not anti Air Source Heat Pump's (ASHP), I installed an Air to Air ASHP myself earlier this year. I nevertheless feel it is important that people are aware of their limitations as well as the benefits.

I was pleased to read that you have a solar PV system and also battery storage. Do you know the size of your PV system and storage batteries? Do you know if the property has a solar power diverter installed? A diverter can be used to provide much of your hot water requirements from Spring through to Autumn, by using the energy generated by your solar PV system along with charging your batteries for use during evening and nighttime. The solar PV will also help power the ASHP during daytime.

I would suggest that you ask how long the solar PV and batteries have been installed. The output from the solar panels does reduce with time, though the manufacturers normally specify a certain reduction over 25 years. The inverter with the solar PV system should last at least 10 years and could last much longer. The batteries also deteriorate with age and number of charges/discharges.

The primary energy source for an ASHP, as the name indicates, is from the outside air. This poses the inherent weakness of ASHP systems, in that as the outside air temperature falls, the energy supply also reduces. This has the effect of reducing the efficiency of ASHP's as the air temperature falls. To minimise energy consumption it is therefore necessary to ensure that an ASHP is operating under optimum conditions.

I would suggest that you ask for details of the calculated heat demand for the property, along with past energy consumption details.

If you have access to the User Manual for the ASHP, check to see if it has Weather Compensation and then ask if it is operational. Weather compensation varies the Leaving Water Temperature (LWT) from the ASHP. The lower the LWT, the more efficient the ASHP will be operating.

Asking the following questions may also be useful.

When was the ASHP last serviced and by whom?

What problems if any have been experienced with the ASHP and its operation?

How effective are the controls at maintaining the desired temperatures throughout the property, particularly during cold Winter days.

If you have any further questions or would like clarification of any point then please feel free to ask.

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