Soldato
- Joined
- 25 Nov 2009
- Posts
- 5,361
Ah, that's simple enough then.
Heat Pumps: anyone have one/thought about it?
- Thread starter fish
- Start date
Soldato
Yes, you do. For various reasons. The one the heat pump installers will definitely tell you about is to ensure that the heat pump avoids short cycling / has somewhere to cycle hot water through.
If you go bigger, you can build a huge amount of system resilience to high cost heat.
TL;DR you can't have a heat pump without a thermal store.
Last edited:
You need some kind of thermal store.
You can put the cylinder in an unheated space like an attached garage, loft or if you are lucky enough to have one, basement.
If you can’t fit a normal sized cylinder, have a look at a heat geek mini store. They are not as efficient but they are a lot smaller.
On the bath front, you don’t need 200 litres of hot water to fill a 200L bath as you’ll be mixing down to get the bath to a temperature which you can actually get into without giving yourself burns.
Soldato
Ah yeah i knew i must be missing something, that makes sense.
I guess the problem i have is i've got nowhere at all to put one, boiler is in the utility on the wall but it's full of other stuff, our house is more of a dormer bungalow so no attic space at all and a solid slab floor so no basement, garage is 20m away from the house so that's a no go too
Only option is to put it in one of the walk in wardrobes understairs but that's miles away form current boiler location and no idea how you'd run new pipes and stuff without destroying the house doing it?
Looks like i'll have to be a late adopter at this rate.
Soldato
Looks like i'll have to be a late adopter at this rate.
Get a Sunamp thermal battery instead of a water tank then, which will fit in a small utility.
Soldato
- Joined
- 21 Sep 2020
- Posts
- 4,185
Mine is co2 fwiw
And if anyone cares, I tried the heating once. Didn’t work for me. 2 showers in the morning at 6 meant there wasn’t enough heat left in it for everyone at the end of the night. So sticking with the two 1 hour heats 12 hours apart.
Soldato
- Joined
- 21 Sep 2020
- Posts
- 4,185
Mitsubishi Electric EHPT20Q R744.
They’ve stopped selling the smaller ones and only do them for commercial properties now. They’ve replaced the domestic ones with R290 so it runs at -25ºc
Soldato
- Joined
- 25 Nov 2009
- Posts
- 5,361
Still not enough.
Had the installer round, they’re going to run 28mm all the way to the manifold as opposed to 22 and talking about adding a second pump on the manifold or maybe just 1 bigger circ pump.
Going to have discussion with their senior heat geek and give me a call.
Soldato
- Joined
- 19 Jan 2006
- Posts
- 4,612
22mm pipe work should theoretically be adequate for up to 36 litres per minute, what heat pump do you have?
Appreciate you've said all open loops, but I assume the flow rate per individual loop has been set correctly and all rooms are balanced correctly on the UFH manifold?
Last edited:
Soldato
- Joined
- 25 Nov 2009
- Posts
- 5,361
I queried how it’d control as it’d be in the house I don’t want any noise from it, also it’s another potential point of failure.
Flow rate been set? As far as throttling the lockshields back yes.
He then set the UFH to the required flows then adjusted LS to get flow through all of the upstairs rads but the manifold flows then started to struggle.
I assume UFH downstairs and rads upstairs isn’t particularly uncommon, not sure why we’re having complications like this.
This was all on the job chit chat, we’ll see what they decide once the Heat Geek(s) get involved.
A mix of UFH and rads is normal for those with UFH. It could be as simple as a gunked up pipe in the system.
The pump in the HP itself are usually more than big enough if the pipes are all sized correctly in all but the biggest houses but they can be replaced with a bigger one if needed. However, two pumps on the same circuit can be problematic.
Check all the valves, strainers etc to make sure none of them are restrictive. A few videos by ‘Urban Plumbers’ get into detail about certain brands of fittings which are very restrictive compared to others despite them being the same official size.
I think this is the video with the relevant information about multiple pumps and what should be avoided:
The pump in the HP itself are usually more than big enough if the pipes are all sized correctly in all but the biggest houses but they can be replaced with a bigger one if needed. However, two pumps on the same circuit can be problematic.
Check all the valves, strainers etc to make sure none of them are restrictive. A few videos by ‘Urban Plumbers’ get into detail about certain brands of fittings which are very restrictive compared to others despite them being the same official size.
I think this is the video with the relevant information about multiple pumps and what should be avoided:
Soldato
For what reason?
Soldato
- Joined
- 25 Nov 2009
- Posts
- 5,361
Thank you for the info.
The UFH is a new install by JK flooring and was only commissioned with the HP.
I
~85msq downstairs on 7 loops
7 rads upstairs, 5 of which are new.
They cleaned the strainer out.
Living room is colder than everywhere else.
19.5-20*C vs ~18.
JK say I should have 13l/m through my UFH and I’m not getting that much.
Soldato
Why is ashp better than electric combi?
They use 3.6 to 5 times less energy.
So say a heat pump was getting a SCOP of 4 and used consuming £500 in electric to heat a house, an electric combi would use £2000 in electric to do the same job.