We’re (all being well) moving into a house that has blown air central heating. Has a lot of fairly ugly vents all over the place and an old(ish) boiler.

I was thinking first job would be rip that out and get modern condensing boiler in (combi if possible), but as I did a bit of online research a lot of people have said it can be very efficient, doesn’t require rads taking up space, so why pay to switch to a system that is potentially no better?

http://www.boilerguide.co.uk/articles/central-heating-systems/warm-air-replacement-modern-warm-air-heating-systems

It still seems a little dated to me so I’m inclined to get rid, but just wondered if other people have them and like them, or have got rid of them in the past?

Thoughts?

Got it in my motorhome, does that count? Works exceptionally well…

If it works and your not planning any other major works then just leave it?

Its a bit old fashioned, not especially efficient and can mean the upstairs rooms end up hot while downstairs is cold, hot air rises after all! Just requires you to close doors, close vents in rooms you dont use etc.

As for ‘unsightly vents’ i think they are a lot less imposing than walls filled with radiators.

Very popular in America. Parents had it no problems, also stops the house getting humid and it gives out nice dry air.

Fantastic. Our 40 year old house had it as standard and when the old unit croaked it we bought another. Muchbbetter than radiators as you get instant heat and as vents are at the windows, no constraints over furniture placement. No bleeding. No leaks. No unsightly radiators to decorate around.

I had it and it wasn’t efficient, but compared to the cost of putting in rads it wasn’t worth changing – where I was it would have meant an oil tank and boiler as well as all the plumbing and upheaval.

Id keep it……Id also be trying to rig up some sort of air condition unit for it in the summer 😆

Our unit can blow unheated air. It’s not chilled but it can help get some air through the house on a hot, still day.

Those who reckon they are inefficient – have you any figures/science to back that up? I’m genuinely interested btw, not spoiling for an argument 🙂

Seen a few comments that it is good for warming a place up, then as soon as it goes off the place goes cold (no stored heat like with rads).

Then I’m thinking, a lot of that must be down to house efficiency (windows / walls) because all the ‘stuff’ in a house stores heat for a while.

How have people found it in terms of going cold quickly?

Much as you suggest. You don’t have a reservoir of heat in the rads and water, but then you’ve not had to heat all of that up in the first place.

It depends how you are containing the hot air in the house. Air is a very poor conductor and escapes very easily so you can lose it before you get the benefit.

I think the key is efficient heat pump system with heat recovery from the outgoing air (not just letting it leak). You can then run the heat pump in reverse to cool the air if needed.

We had one when we first moved into our current house (17 years ago) it did heat very quickly but wasn’t cheap to run and blew dust everywhere when it was on. It was noisy at start up and as only British gas would touch it for servicing locally, we had to endure them condemning it at every visit! To pass then current regulations, i ended up with a vent 50cm2 in my kitchen (where the boiler was sited)that pretty much made a kitchen warm air vent redundant! Give a try, it may work for you ours was old when we moved in, so newer versions may be better. I now have a combi boiler system.

My parents have it – been in place since the late 60’s and rarely had a problem.
My Dad’s a scientist (so he understands convection and other relevant physics), doesn’t spend money if he doesn’t have to and is a bit of a perfectionist. If he’s happy with its efficiency and cost then it’s probably alright 🙂
More freedom to place furniture where you want it is a win too.

According to my mum they always used to be inefficient – modern ones may be better I dunno.

Also, you can often hear people talking or doing OTHER THINGS in different rooms, via the vents.. beware.. 🙂

Those who reckon they are inefficient – have you any figures/science to back that up? I’m genuinely interested btw, not spoiling for an argument

Unscientific, but since I moved to an oil fired boiler, my overall energy costs have gone down. Heating is a large part of that judging by oil use over winter vs. summer. Like I said though, the cost of changing it might be prohibitive anyway, it’s like PV solar without any kind of moral win thrown in 🙂

Radiators are great for drying stuff on too.

Warm air vents are better 🙂

Others have commented on the effectiveness, let me mention some potential risks.

A mate and I rented a 70’s house with this a while back, he was working from home at the time and was getting bad headaches. We had a minor gas leak on the pipe into the cooker to got a plumber out to have a look at it and he also had a quick look at the heater. Condemned it on the spot. Not only were the burners all blocked up so it was producing carbon monoxide, but the heat exchanger was cracked so it was pumping the CO through the house nicely.

This was mid November, he said had we continued to run it then my mate wouldn’t be alive by Christmas 😯

So, get it checked out would be my suggestion!

Cheers, Rich

watch Holmes on Homes on Discovery Channel(s); it seems to be the norm in Canada

Most Canadian houses (including mine) are forced air heating. Did confuse me when I first arrived. Works for us and it is down to -30C in winter. I like the directness of the control; no lag to get lots of water in a system heated up just adjust the temperature and away it goes. Don’t really notice the vents as being worse than radiators. On mine you can close and adjust vents to make sure house has a roughly even temperature.

Yes I’ve visited a few houses in Canada that have it, seemed a very sensible system to me.

The woman we’re buying from is a smoker so part of me has a ‘gross’ feeling towards the system 🙁

We have it. It’s very good.

I prefer the vents to radiators. It’s instant heat and if you have the control system which monitors the heat decay in the house it gives a very constant heat (rather than on/off all the time).

Our heater unit gave up the ghost last year, and it was very expensive to replace, but I’d rather have the warm air than the wet radiator equivalent.

My main disappointment is that the timer aspect of the control means there’s nothing very clever about when the system switches on/off and setting different temperatures for different times of the day.

EDIT:
Plus 1 for turboferret – you need to look after the system.
Other advantages: if you have an electrostatic filter, your air is cleaned 6 times an hour (or something). My asthma is 1000 times better for it.
Anecdotally, most people’s gas usage is 30-40% hot water, 60-70% space heating. Ours is opposite – 60% of our gas usage is water heating (hence me having quotes for solar thermal 😉 )

Depends on the type, the blow and suck versions (technical terms!) that are used in modern houses are meant to be good, the older ones with blow only less so.

Some areas like where I am now have loads of them about, but if your area doesn’t just remember that its a different qualification to the normal gas one, so less gas fitters will be available to you.

I had it in my previous house and I did not like it. It came on quickly which was good, but I found it then blew out hot air so I got hot, but then when it turned off, the house (and I) got cold very quickly afterwards as the warm air just disappears. It then came back on again a short while later as the house had cooled down again. I just found it irritating. Much happier with radiators as they radiate heat for ages after the boiler has gone off and keep the house at a more consistent temperature. Mine was an old 60’s house with the original boiler and the fans were quite noisy as well and to hear them continually coming on, running and then going off was tiresome.

Also finding someone qualified to service it was not easy as were getting parts. If anything major had gone, it was on the verge of being unrepairable so would have needed a radiator system putting in anyway.

When I first moved in and got it serviced mine was also turned off on the spot as there was a crack in the flue pumping carbon monoxide into the loft 🙂

* That’s my opinion and it probably differs from others 🙂

Blobonastick – You can get smarter timers. Mine has four periods per day and I can set each one to it’s own temperature.

SkillWill – A full duct clean might do wonders but I sympathise.

Sweaman – do you know the make please?

My furnace and timer system are by carrier. I’m in Canada though so no idea if they sell in the U.K.

Ah. No, my system is Johnson and Starley which has the modulation system on it which does a lovely job of maintaining a constant house heat, but only comes with a 2-period timer for both heating and hot water. Temp is set by a thyristor-stat.

Thanks for looking though.