Are antifreeze valv...
 
Notifications
Clear all

Are antifreeze valves essential for a glycol free ASHP system?

20 Posts
8 Users
16 Reactions
3,449 Views
(@mike-h)
Reputable Member Member
1837 kWhs
Joined: 3 years ago
Posts: 197
Topic starter  

During a recent upgrade to my 12kW Samsung ASHP set up, the glycol was removed as requested. I expected one or more antifreeze valves to be fitted, but I was told on good authority that these were not required. So I wondered if anyone had any views on the pros and cons of fitting antifreeze valves? If fitted, is one on the return flow sufficient or should there be one on the leaving flow too? Is anyone in the same position, having no glycol and no antifreeze valves?

I must admit to feeling a little anxious when all occupants of our three terraced cottages were away at the same time after Christmas, when it went very cold and any power cuts would have gone unnoticed!


   
👍
1
Quote
Mars
 Mars
(@editor)
Illustrious Member Admin
27488 kWhs
Joined: 4 years ago
Posts: 3078
 

Great question. @heacol will know the answer.

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


   
ReplyQuote
(@heacol)
Noble Member Contributor
2585 kWhs
Joined: 4 years ago
Posts: 394
 

According to Samsung, you either have to have antifreeze valves or glycol. As glycol will add 20%+ to your heating bill, it is not really an option. In reality, if you want top install them, 1 will suffice on the lower pipe, however, it is nearly impossible for ice to damage the Samsung unit as the internal connecting pipes are rubber, and will expand on freezing. 

It is up to you, I have about 600 units in the field, of all makes, and no glycol or antifreeze valves, and have not, in the last 15 years, had a single unit damaged by ice.

 

Director at Heacol | Expert Heat Pump Consultant | Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.


   
👍
1
ReplyQuote



(@mike-h)
Reputable Member Member
1837 kWhs
Joined: 3 years ago
Posts: 197
Topic starter  

@heacol Thanks Brendon, that is very helpful.


   
👍
1
ReplyQuote
Mars
 Mars
(@editor)
Illustrious Member Admin
27488 kWhs
Joined: 4 years ago
Posts: 3078
 

@heacol I’ve also wondered how that worked. Will the system remain protected if there’s a big winter storm with temperatures below zero and power lines get taken down, and we’re without power for a few days. Wouldn’t that do some damage and wouldn’t stuff that shouldn’t freeze, freeze?

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


   
ReplyQuote
(@heacol)
Noble Member Contributor
2585 kWhs
Joined: 4 years ago
Posts: 394
 

@editor I am not saying the units will not freeze in some conditions, and I have seen many, however it is the design of the unit it'self that will determine if there is any damage. Units that have standard circulator pumps in them such as Valiant, Midea/Clivet and others are vulnerable as standard circulators can easily be damaged by freezing, some units with pumps like Panasonic are not affected as they have taken the time and effort to make their own pump. Units that have no pump, like Samsung and Mitsubishi, are not usually affected.

As I said, it is your choice. My choice is Panasonic hands down, it is so far ahead of the pack for many, many reasons.

Director at Heacol | Expert Heat Pump Consultant | Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.


   
ReplyQuote
Abernyte
(@abernyte)
Honorable Member Member
4325 kWhs
Joined: 2 years ago
Posts: 223
 

Posted by: @heacol

As glycol will add 20%+ to your heating bill,

Really? That is an enormous claim, citation required.  I am aware of talk around a small increase,  but 20% plus ( by how much plus) is astonishing.


   
ReplyQuote
(@david-i)
Active Member Member
45 kWhs
Joined: 1 year ago
Posts: 4
 

@abernyte Difficult to get specific figures but I work on

Water 4.184kj/kg.K. 

Monopropylene glycol 3.884kj/kg.K (@30%)

Monoethylene glycol 3.712kj/kg.K. (@30%)

Pump at say 50W will cost 1p/hour to run, with glycol added 1.1p/hr.

I work for a manufacturer of heat pumps and boilers.


   
👍
1
ReplyQuote
Mars
 Mars
(@editor)
Illustrious Member Admin
27488 kWhs
Joined: 4 years ago
Posts: 3078
 

@david-i interesting. Thanks for sharing. So do you avoid glycol in systems too?

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


   
ReplyQuote



Toodles
(@toodles)
Famed Member Contributor
11675 kWhs
contributor
Joined: 3 years ago
Posts: 1877
 

@editor No Glycol in our Daikin installation but we do have two antifreeze valves. When the ‘Boss’ came to do a little ‘snagging’, he was surprised (and I think, a little miffed due to their cost) that his installers had fitted them in both pipes rather than just one. I was rather pleased that they had fitted them in both as surely, if the pipes are both very cold, isn’t better that they both drain? (Or is not how this precaution is supposed to work perhaps?). (Daikin are coming today to carry out the first annual service) Regards, Toodles.

Toodles, he heats his home with cold draughts and cooks his food with magnets.


   
👍
1
ReplyQuote
(@allyfish)
Noble Member Contributor
4262 kWhs
Joined: 2 years ago
Posts: 483
 

Anti-freeze valves provide some guarantee of a fail safe if the system is unpowered for a long period and all other forms of frost protection such as the unit pump circulating water and/or frost protection heating in the circuit fail. You are into double jeopardy however - a long power failure coincident with extreme prolonged low temperatures. Anti-freeze valves should be on both outdoor unit supply and return pipes at the lowest point. Glycol isn't really required in the UK provided external pipework is properly insulated and protected.

Glycol lowers the specific heat of water with increasing concentration, it's the renewable parallel of adding hydrogen gas to mains gas methane, which lowers the calorific value of the resulting blend. That's why using H2 for domestic heating is a dumb idea, aside from the cost of producing it and the safety issues it creates.


   
👍
3
ReplyQuote
Abernyte
(@abernyte)
Honorable Member Member
4325 kWhs
Joined: 2 years ago
Posts: 223
 

Which does not get us anywhere near a 20% plus energy cost increase caused by using glycol.


   
👍
1
ReplyQuote
Page 1 / 2



Share:

Join Us!

Trusted Installers

Struggling to find a reliable heat pump installer? A poor installation can lead to inefficiencies and high running costs. We now connect homeowners with top-rated installers who deliver quality work and excellent service.

✅ Verified, trusted & experienced installers
✅ Nationwide coverage expanding
✅ Special offers available

👉 Find your installer now!

Latest Posts

Most Active This Week

# Name kWhs
1 Mars 364
2 JamesPa 150
3 Pooneil 128
4 Majordennisbloodnok 112
5 bontwoody 109
6 Toodles 108
7 Heatgeek 106
8 cathodeRay 94
9 Transparent 87
10 Tim441 65
x  Powerful Protection for WordPress, from Shield Security
This Site Is Protected By
Shield Security