Browse Forums Heating, Cooling & Insulation 1 Oct 13, 2013 9:51 pm Hello, A property that my partner and I are interested in purchasing has the above mentioned system installed for heating and cooling. Now it doesn't actually appear to be zoned, out of interest is that something we can adjust later on - is it difficult? We are just concerned about the costs of heating parts of the house we aren't using. Also, the evaporative cooling - am I right in thinking this is not as good as actual air conditioning? The house is single glazed, and we are wondering if the cooling solution will be enough during Melbourne summers. Any thoughts appreciated! Thanks, Ian Re: Ducted heating paired with evaporative cooling. 2Oct 14, 2013 12:18 pm I didn't think it was even possible to pair heating and evap cooling in the same ducts; mainly because evap cooling relies on pushing a large volume of air though the house to cool it and therefore the ducts are much wider than heating ducts. There are many discussions here re: evap versus refrigerated cooling in this forum. Basically evap cooling can only cool to a maximum of around 8c - 10c less than the ambient outside temperature; and for it work work effectively, you must leave windows open. Because it works by evaporation; ie the warm air is drawn through wet pads (same effect as wetting your finger then blowing on it gently - the air movement evaporates the moisture taking the heat out of it), on humid days they are not as effective and can make the conditions inside your house even more uncomfortable. Having said that, on a dry summers day at up to say 35c, they can be very efficient. Melbourne summers (when it is hot) tend to be dry, but we do get some humid days as well. Since this system is already in place, you could just add a split system to your living area so on those really hot and/or humid days, use that instead of the evaporative system. Re: Ducted heating paired with evaporative cooling. 3Jan 27, 2014 2:48 pm I'd be very surprised if the heating and cooling were using the same ducts! Evaporative has some advantages over refrigerated. Cheaper to run (about one tenth the price) for starters. The air is a bit more moist - that is good and bad depending on yourself (dry skin or not, if you simply don't notice it etc) and the humidity. I find refrigerated air conditioning to be a bit addictive/deceptive as you don't notice how cold it's getting and before you know it you've cooled your room/zone/house to twenty degrees and spent a bit of coin doing it (Victorian electricity prices!!!). But it's something else to have a room cooled to 22 degrees on a stinking hot day and it's a nice, crisp coolness as well - modern luxury! If they were price-equal in purchase and running costs I'd go refrigerated but they're not so.... In practice I would say the difference between the two is that evaporative is like sitting on the beach with breeze coming off the water and the refrig is like Mt Buller in summer time. With regards to which system can do what, with evaporative you can calculate how effective it will be by taking the Delta T value at the BOM web site, reducing it by 20% and then subtract that from the outside air temperature. So a 35 degree day with 15 degree Delta T would see air coming in at around 23 degrees. A refrigerated system runs a close loop inside your room/zone/house so it depends on the temperature of your inside air, and how well it can cool that air down. Re: Ducted heating paired with evaporative cooling. 4Jan 27, 2014 4:26 pm Hi Ian, I'm going to do this in my build, with eyes open about the trade-off in costs/energy vs efficacy of reverse cycle. Different ducting certainly is required for the two systems and I'm also going to add ceiling fans in key rooms. As said above, the evap falls short on those baking days but I'm building reasonably close to the water (Bellarine Peninsula) so I'm counting on heat dropping off in the evenings most of the time. I figure I can put up with fans for the few really bad days per year when the evap. will really fall short. If this turns out to be too uncomfortable I can always add a reverse cycle to one or two of the rooms. Re: Ducted heating paired with evaporative cooling. 5Jan 28, 2014 7:10 pm Hi all, We live in Adelaide and have evap cooling and ducted gas heating which is zoned. In the recent heatwave when the temp outside was 45C it was 27C inside and we've never been disappointed with it. It is important to vent it properly by having some doors and windows open. Admittedly, on humid days we also run ceiling fans to help as it isn't as effective. The gas heating does use separate ducts but is zoned so we only heat the areas we need to which makes it very economical. Initially it was more costly to set up this way but we're retirees and couldn't afford the costs of high electricity bills. We did put in a small 1.5k solar system so our electricity costs last year were $300 all up:) Handover February 2011 Happy with our home Re: Ducted heating paired with evaporative cooling. 6Jan 28, 2014 7:44 pm robinred55 Hi all, We live in Adelaide and have evap cooling and ducted gas heating which is zoned. In the recent heatwave when the temp outside was 45C it was 27C inside and we've never been disappointed with it. It is important to vent it properly by having some doors and windows open. Admittedly, on humid days we also run ceiling fans to help as it isn't as effective. The gas heating does use separate ducts but is zoned so we only heat the areas we need to which makes it very economical. Initially it was more costly to set up this way but we're retirees and couldn't afford the costs of high electricity bills. We did put in a small 1.5k solar system so our electricity costs last year were $300 all up:) Hi there Can you please advise the brand of your evaporative andducted gas system and the installer? Cheers boosts (Sa) Hi all, sorting out the ducted air con for a 350sqm double story house. Does this placement sound reasonable to you? Also, I plan to have 6 zones I think. Living room… 0 0 Hi all, sorting out the ducted air con for a 350sqm double story house. I think i plan to have 6 zones I think. Living room (mainly for entertainment so not used often),… 0 0 0 6295 |