Keeping warm - the ventilation edition

It's been a bit quiet around here as I'm struck down with some kind of horrible lergy - but I did manage a bit of fossicking around in the attic today before I crawled back into bed - you know how when you're sick the first dose of paracetamol often makes you think you're actually okay until you get knocked off your perch mid-morning? So anyway, no photos or real progress to speak of but we've been learning lots about heating and ventilation so I thought I'd share a bit about the latter.

Our house came equipped with two HRV systems. I know this will excite some people - and perhaps in some houses HRV systems are worth having, but I am not sold. Ventilation is good, yes, but several thousand dollars is a big outlay for something that only somewhat dries out the air.

That's a bit beside the point when someone has already put the systems in, though, so we thought we'd give it a whirl. Well, we've been here for two months now, and used the HRVs for the first month (maybe a bit more) while we worked out what to do about heating (there were two heat pumps, but they only heated the rooms they're in, leaving the rest of the house pretty cold).

We've now decided on our heating solution (a reasonably uncommon option for Kiwis - ducted gas central heating - more on that soon as we're in the process of installing the ducting ourselves) and have had a bunch of electrical work done, including having the HRVs removed. Have we noticed a difference? Not really.

We're well aware that ventilation is very important for a healthy home - and lacking in many NZ houses, probably mainly because they feel so cold - but there are other ways to achieve that.

The best way to ventilate, and cheapest by a long shot, is to throw open the windows - as many as possible, in particular those which will catch the cross wind - for 10-30 minutes once a day. Yep, those minutes will be a bit chilly in winter, but a dry house is healthier and easier to heat. Once you've closed 'em up again crank up your heating and it'll warm back up in no time.

If your house is particularly damp (i.e. if you notice a lot of condensation on the windows or walls) you might need to take more targeted action.

The first thing is to avoid putting moisture into the air if possible. Just breathing adds some moisture but don't stop doing that! But there are three main culprits, all of which are reasonably easily solved:
1. Cooking 
Make sure you have a good rangehood over your hob (and that you use it!), and keep lids on pots as much as possible when cooking.
2. Showers
Install a fan in your bathroom if there's not one already - if possible add it to the same circuit as the lights with a delay timer so it runs for a while to clear steam after a bath or shower.
3. Drying clothes
If possible, dry your clothes outside on the line. If you have a dryer, duct it! This is pretty easy to do - you can buy ducting kits from hardware stores and appliance stores, add a couple of hours of your time (or pay a handyman if you're able) and you're all sorted. Here's the bit I only learned recently - if you can't dry your clothes on the line outside you are better off putting them into a ducted dryer than hanging them on an airer inside. You'll likely use more energy getting the water out of your house than you would have done running the dryer.

The small droplet symbol on the
left shows it's on the right mode

Okay - got prevention covered but still damp inside? If you have a heat pump, try running it on the dehumidifying mode for a few hours next time you're out. This only works when it's cooling so it will reduce the temperature, but does an okay job at removing moisture at a pretty low cost. In our old house we did this for about three hours once every couple of weeks in winter, which was enough for us (we actually probably wouldn't have needed to do that I'd learnt the bolded bit above about the dryer a bit sooner).

Freestanding dehumidifiers are even better at drawing out the moisture, so if you're really struggling to keep the walls dry, buying or borrowing one of those and moving it around the rooms of your house should do the trick.

By all means if these things don't solve your problems maybe look into a ducted ventilation system - but please try the cheaper things first! You might be surprised. :-)

Back to our disaster house new home - there was no extraction at all in the kitchen when we moved in, and no outdoor clothesline or dryer ducting. So I'm thinking the previous owner may have jumped the gun a little on the HRVs... Oh, and there is a little moisture issue at the back of the house where the back wall of the laundry is actually the concrete retaining wall - that one will be a bigger problem for us to solve a wee way down the road... Not looking forward to that!

Have you lived in a horribly damp house? Do you have any tips to add?