HVAC system for residential use

[Indy]

I’ve posted on the topic of active cooling before but the responses were quite limited, and only about running your ASHP in reverse. I understand this acts more like a trim function rather than a true active air con system.

 

What I’m after is similar to the HVAC systems found in offices - where you enter a room and there’s a thermostat by the door. Set it 20c and the air con kicks in, set it higher and the heating kicks in.

 

Does something like this exist for the residential market, by which I mean at reasonable prices? I’ve heard of MVHR systems where you can utilise the ducting for active cooling - maybe a hybrid system I’m not aware of?

 

[Mr Punter]

The systems in offices normally work by heating or cooling air and transferring it via very large ducting.

 

MVHR systems in dwellings is only for efficient ventilation and will not do heating or cooling to any significant extent.

 

If you want a system that heats or cools the air you could look at a split or multi split a/c system.

[crispy_wafer]

Sounds like you are after multi split AC heatpumps or Air to Air heatpumps as they are known in some circles, reasonable pricing...  Depends on how many rooms and the amount of area you are looking to cool/heat.  They can emit via radiator looking things, ceiling ducts, wall mount units, built into bulkheads, ceiling cassettes etc.

 

Usually the same mfr's as the regular ASHP's so likes of  Daikin, LG, Panasonic, Hitachi, Midea, Haier etc.  Panasonic openly market heating and cooling on some of their units and have fan coil units to spread the cool air.

 

The only issue - i think may be around the number of units you are allowed to site before getting planning involved.

 

Something I'm looking into at the moment, it'd be nice to have a solution I can integrate now for heating/cooling whilst I'm at first fix. 

[Indy]

Yes, multi split air con! Thank you - that’s pretty much what I had in mind but didn’t know what to search for. 

 

A quick Google tells me that between 5 and 9 units are possible with a single external heat pump. That is probably what we’re after.

I would ideally like to get the ceiling or wall cassettes so that it’s a bit more discrete versus wall mounted units, and ideally done at the build stage rather than retrofit.

 

Would the ducting for this be standalone or something that can be shared with an MVHR system? 

 

[crispy_wafer]

Ducting would be standalone as far as I know, it's a larger bore and needs to be insulated, aircon recirculates, mvhr brings in outside air.  I used Our Guide to Air Conditioning | Air Conditioning World as a guide to work out unit capacity and rough requirements, but am consulting local installers too.  I think a max of 5 indoor units from each outside unit, but depends on the duty requirements, I think if all units need to run at full tilt and the total of the indoor units are rated higher than the outside unit then indoor units are derated to cope with demand.  But in my case I cannot forsee when all units will be going at the max and requiring more than the outdoor unit can provide.

 

Centralised control is a nice to have as well, as is energy saving features.

 

We've probably got more informed posters than me on this site somewhere though.  So take what I say with a pinch.

 

 

[Mr Punter]

15 hours ago, Indy said:

Would the ducting for this be standalone or something that can be shared with an MVHR system? 

 

The split a/c systems do not circulate any air between outside and inside, just the refrigerant gas gets pumped round between the indoor and outdoor units through insulated pipework.  You will still have your MVHR for your ventilation.