Search with Wattson

Notifications

Clear all

Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!

Shutting down heating when out for the day - data

jamespetts · 2024-11-04T23:59:47Z

Having just had a new heat pump (Vaillant Arotherm + 7Kw) installed, I wanted to test how the energy usage wold be affected by shutting the system down while out for the day. I have read and heard suggestions that, unless going on holiday for multiple days at a time, it is more efficient to leave the system running constantly, but that made me sceptical, since it makes implausible assumptions about how much power is consumed during a compressor restart. So, yesterday, I was out of the house from around 0830h to 1900h. I turned off the heating using the Vaillant app just as I was leaving and turned it on again just when I was about to start the journey home (about 1 hour door to door). The weather conditions in London yesterday were very similar to those to-day, with an average outdoor temperature measured by my heat pump of 12.3C compared to 11.5C to-day. Yesterday's overall power consumption was 2.1kWh with a COP of 3.2. To-day's, with me working from home all day, was 3.1kWh with a COP of 3.2. This does suggest that leaving the house for multiple hours at a time does indeed require the system to be shut down during the away periods to minimise power usage.

Page 4 / 4 Prev

Air Source Heat Pumps (ASHPs)

Last Post by jamespetts 2 years ago

40 Posts

8 Users

4 Reactions

12.5 K Views

RSS

jamespetts

(@jamespetts)

Eminent Member Member

Joined: 2 years ago

Posts: 31

Topic starter 07/11/2024 11:57 pm

To-day's data: heating off between circa 1530 and 2230 outdoor temperature 10.7C, heat curve 0.50, 2.4kWh consumed.

ReplyQuote

jamespetts

(@jamespetts)

Eminent Member Member

Joined: 2 years ago

Posts: 31

Topic starter 12/11/2024 12:11 am

Friday and Saturday's data are probably contaminated with confounding factors as I had builders in leaving doors open. But Sunday's and to-day's are instructive.

Sunday: heating on all day, average outdoor temperature 9.3C, heat curve 0.50, 4.3kWh consumed, reported COP 3.2

Monday: heating off from 1100h - 1700h, average outdoor temperature 9.9C, heat curve 0.45, 3.2kWh consumed, reported COP 3.3

ReplyQuote

Mars

(@editor)

Illustrious Member Admin

Joined: 6 years ago

Posts: 4958

12/11/2024 8:58 am

@jamespetts the one thing you’re not mentioning is the temperature inside the house. Is it uncomfortable or cool when you get back, and if yes, how long does it take to warm up?

🔥 Britain’s Heat Pump Shitshow
How Installing a Heating System Became a National Nervous Breakdown
Free UK shipping.
📗 Heat Pumps Explained
A Jargon-Free Guide for Homeowners
Rewritten and updated for 2027
📘 From Zero to Heat Pump Hero
🛠️ Bodge Buster
New to heat pumps?
Take the Heat Pump Fundamentals course and use INTRO50 at checkout for 50% off.

👍

ReplyQuote

jamespetts

(@jamespetts)

Eminent Member Member

Joined: 2 years ago

Posts: 31

Topic starter 12/11/2024 10:26 am

Posted by: @editor

↑

@jamespetts the one thing you’re not mentioning is the temperature inside the house. Is it uncomfortable or cool when you get back, and if yes, how long does it take to warm up?

So far, the house has been comfortably warm when I get home. The door to door journey is about an hour, although yesterday, I stopped to talk to some colleagues before I left work and after I had turned the heating on and then took a long walk before getting on the train, so the house had even longer.

👍

ReplyQuote