Forums

Forums
Renewable Heating
Air Source Heat Pum...
Ducting an air sour...
 
Notifications
Clear all

Ducting an air source heat pump for the purpose of potentially fitting it the cellar

 
Page 2 / 2
Air Source Heat Pumps (ASHPs)
Last Post by Gild 6 months ago
18 Posts
5 Users
5 Reactions
1,450 Views
RSS
Mars
 Mars
(@editor)
Illustrious Member Admin
26256 kWhs
Veteran
Joined: 4 years ago
Posts: 2979
14/09/2024 8:34 pm  

@gild yeah, that’s a tricky one. I just don’t think the cellar is going to work. I’ve had hypothetical conversations with installers about air source heat pumps in garages, sheds, outbuildings, etc. and it always comes back to movement and replacement of air. I’ll put this question to some knowledgable installers this week. I’m recording my next episode of Homeowners’ Q&A and this could be a great question.

Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb

Subscribe and follow our Homeowners’ Q&A heat pump podcast


   
👍
1
ReplyQuote
 Johnmo
(@johnmo)
Prominent Member Member
2299 kWhs
Joined: 2 years ago
Posts: 422
14/09/2024 8:47 pm  

No idea how big a heat pump you need, but this would easy to do, or even cascade 2x.

https://trianco.co.uk/activair-indoor-9111-9111

Maxa i32V5 6kW ASHP (heat and cooling)
6.5kW PV
13.5kW GivEnergy AIO Battery.


   
ReplyQuote
 Gild
(@gild)
Active Member Member
57 kWhs
Joined: 6 months ago
Posts: 7
Topic starter 14/09/2024 9:08 pm  

@editor Thanks! Fwiw I can open enough intake area for the basement that would be roughly twice the fan's apartue area. Maybe even more.

The alternative would be to install an oil boiler which would be a sad thing to do in 2024...

@johnmo Thanks! That's interesting as it's actually small enough that I can put it in different sides of the house (maybe in the other basement too) I think I'll need 3.

Are.these inverter units? I'll start reading more. Edit: I see a buffer in the installation doc so probably no inverter:/

 

Cheers.

This post was modified 6 months ago 2 times by Gild

   
ReplyQuote
 Johnmo
(@johnmo)
Prominent Member Member
2299 kWhs
Joined: 2 years ago
Posts: 422
14/09/2024 9:22 pm  

Posted by: @gild
↑

Are.these inverter units?

Would doubt it. But my 6kW inverter ASHP is running at around 4 to 5kW are the moment no less. So cascade them you should be able to 3x 3kW when really cold and 3 kW when just cold enough to need heat. 30 min on off cycle your down to 1.5kW etc.

From reading the manual (many months ago) I recall the ability to drive an external heat source, this could drive a second unit easily enough then a third I would think.

Maxa i32V5 6kW ASHP (heat and cooling)
6.5kW PV
13.5kW GivEnergy AIO Battery.


   
👍
1
ReplyQuote
 AllyFish
(@allyfish)
Noble Member Contributor
4175 kWhs
Joined: 2 years ago
Posts: 477
16/09/2024 7:48 am  

The problem with ducting or enclosing a ASHP is adding external static pressure (ESP) to the fan. The fan impeller is designed to move large volumes of air with no ESP other than the unit evaporator coil and inlet and outlet grilles. As soon as you add anything else into the airflow; a grille, louvre, a duct, a deflector or hit'n'miss fence, etc., you add ESP to the fan & reduce the volume flow through the unit. That will impair the capacity and performance of the ASHP, with risk of the ASHP starting to recycle air that it has already processed, or the fan going into a stall, which is where the airflow through the fan impeller collapses and drastically reduces.

You could include a second in-duct fan in series with and interlocked and controlled by the in-built ASHP fan, and this is sometimes done with split A2A systems or ducted cooling systems in basements or cellars, but it needs specialist design, and the second fan generates noise and consumes additional power. System efficiency is always lost.

I've read acoustic reports where an acoustic engineer's suggestion is to acoustically enclose an air-cooled machine or air source heat pump unit. Well, it fixes the noise problem, but so reduces the capacity of the unit that you might as well switch it off, which is a cheaper and simpler solution!

This post was modified 6 months ago by AllyFish

   
🤩
1
ReplyQuote
 Gild
(@gild)
Active Member Member
57 kWhs
Joined: 6 months ago
Posts: 7
Topic starter 17/09/2024 5:04 pm  

Thanks @allyfish . Yes, I mentioned static pressure as the main issue here. That's why I specifically wondered about the exaust as this will be the real ducted part.

The inflow will be nearly resistant free I think, as I can create a large opening for the cellar. (depending on how I'll do it, but can be twice or 4 times the surface area of the fan) so it should be pretty free for the air supply.

I am not worried about acoustics there to be honest, there is a thick concrete ceiling between where I want to place it to the house.

Thanks again for taking the time for your detailed answer!

 


   
👍
1
ReplyQuote



Page 2 / 2
Forum Jump:
  Previous Topic
Next Topic  
Share:

Join Us!

Heat Pump Dramas?

Thinking about installing a heat pump but unsure where to start? Already have one but it’s not performing as expected? Or are you locked in a frustrating dispute with an installer or manufacturer? We’re here to help.

✅ Pre-Installation Planning
✅ Post-Installation Troubleshooting
✅ Performance Optimisation
✅ Complaint Support (Manufacturer & Installer)

👉 Book a one-to-one consultation now.

Latest Posts

x Powerful Protection for WordPress, from Shield Security
This Site Is Protected By
Shield Security →