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JamesPa

23 minutes ago

JamesPa

Replied to the topic Is the "divide by 2900" rule still valid?

There is a thread on openenergymonitor which does suggest that the Vaillant Arotherm plus 7kW in particular doesn't deliver the (typically, depending on FT) 8.5kW it claims during defrost, and is more like its sticker capacity of 7kW, with the 5kW likewise delivering closer to its sticker output dur...

AndrewJ

1 hour ago

AndrewJ

Created the topic Is the "divide by 2900" rule still valid? in Air Source Heat Pumps (ASHPs)

Brother in law has recently had a survey completed with the heat loss estimated at 9.73kW, a recommended 12kW Arotherm and a flow temp of 50c at -3c for a SCOP of 3.97. There seems to be some suggestion of requiring a 30% oversize (a new thing recommended within the last 2 months - by whom, Vaillan...

Toodles

5 hours ago

Toodles

Replied to the topic Do I add Air Con or MVHR to existing A2W ASHP?

@bobflux Thanks very much for that information and advice; air con is the answer then! I have read that some units incorporate dehumidifiers so must take a closer look at those. Regards, Toodles.

bobflux

6 hours ago

bobflux

Replied to the topic Do I add Air Con or MVHR to existing A2W ASHP?

About the original question: Flow rate for MVHR is adequate for ventilation, but way too low for air conditioning. Heat capacity of air is only 1200 J/°C/m3, so consider an air conditioner with 2kW cooling power: - Intake indoors air at 21°C - Blows cooled air at 5°C - DeltaT: 16°C - Flo...

Old_Scientist

24 hours ago

Old_Scientist

Reacted to a post in the topic Do I add Air Con or MVHR to existing A2W ASHP?

bobflux

1 day ago

bobflux

Reacted to a post in the topic Heat Pump Books For Beginners: The Ultimate Guide to Heat Pumps, Bodge Buster, From Zero To Heat Pump Hero & Britain's Heat Pump Shitshow

Toodles

1 day ago

Toodles

Replied to the topic Do I add Air Con or MVHR to existing A2W ASHP?

@old_scientist I’m thinking along the lines of a multisplit external unit with 4 internal units. Has anyone any views or experience of the Daikin Perfera range please? After the news this morning that with the imminent El Nino likely to cause record temperatures next year, I wish to be ready for t...

jimbo

1 day ago

jimbo

Reacted to a post in the topic Aira Heat Pump: Stylish Scandinavian Heating

Mars

1 day ago

Mars

Replied to the topic Heat Pump Books For Beginners: The Ultimate Guide to Heat Pumps, Bodge Buster, From Zero To Heat Pump Hero & Britain's Heat Pump Shitshow

Britain’s Heat Pump Shitshow is now available to pre-order on Kindle for just £2.99 and will be released on 7 September. It isn’t an attack on heat pumps. Good systems work brilliantly, and the book gives the competent people doing this properly the credit they deserve. It is an attack on the co...

Old_Scientist

2 days ago

Old_Scientist

Reacted to a post in the topic Solar Energy - No Thanks.

AndrewJ

2 days ago

AndrewJ

Reacted to a post in the topic Do I add Air Con or MVHR to existing A2W ASHP?

Watcher

2 days ago

Watcher

Replied to the topic Do I add Air Con or MVHR to existing A2W ASHP?

Cloudy one done, might get the sunny one tomorrow or definitely Saturday. Midea 3.5kw, 2.5 years old. It really is not noisy, quieter than a large stand fan we run, but maybe like being in the kitchen when the fan oven is roasting Sunday lunch…nice when you switch it off to eat!

AndrewJ

2 days ago

AndrewJ

Replied to the topic Do I add Air Con or MVHR to existing A2W ASHP?

@watcher actually, a picture from inside the living room on a sunny day and cloudy day, at midday, with the shutters open would be very useful. What you mention is one of the concerns we have. What AC do you have and how old is it?

Mars

2 days ago

Mars

Reacted to a post in the topic Do I add Air Con or MVHR to existing A2W ASHP?

Watcher

2 days ago

Watcher

Replied to the topic Do I add Air Con or MVHR to existing A2W ASHP?

@andrewj Shutters are very effective, but do darken the room even when ‘open’ and ‘bring the room in’. I have a set of 4 that live in my garage for 8 months and lean against my south facing lounge when needed. (Lot this year!) Happy to send a pic if it helps. Regarding comments about ha...

AndrewJ

2 days ago

AndrewJ

Replied to the topic Do I add Air Con or MVHR to existing A2W ASHP?

@lizzie that is useful info, thanks. I’m currently considering external shutters to try and reduce solar gain as our house typically heats up to over 32c in summer - living areas and bedrooms. Aircon is a possibility but we really want to avoid more energy expenditure and another box outside. Shu...

Mars

3 days ago

Mars

Replied to the topic The good, the bad and the not that great – my heat pump installation

@burtis, I’ve followed this thread pretty much from the beginning and what an exhausting way for it to end. I think @JamesPa is right… if there’s anything we can still help with, keep throwing it at us. But the bit that really sticks with me is that after nearly three years of complaints, inspecti...

Ian S

3 days ago

Ian S

Reacted to a post in the topic Starting Our Heat Pump Journey: 1962 build 3 bed detached house

Burtis

3 days ago

Burtis

Replied to the topic The good, the bad and the not that great – my heat pump installation

@jamespa Thank you sir the help and talking on here was definitely helpful much appreciated 👏 Sadly they way things are it seems customers have a raw deal of it sometimes if it all goes wrong

Burtis

3 days ago

Burtis

Reacted to a post in the topic The good, the bad and the not that great – my heat pump installation