2009/11/09

Heat pump installed

We finally got our heat pump installed after about 2 months of waiting. They seem to be in big demand at the moment and the installers had to order one from Japan and wait for it to arrive.
I decided to get a Fujitsu Nocria AWTZ14L because it was the most efficient heat pump I could find in its power output rating. It can move 6Kw of heat into the house and has a heating COP of 4.44. There are some more efficient heatpumps around - I was keen on a Panasonic CS-HE9GKE with a heat output of 3.6Kw and a COP of 5.22 but since it was potentially to be the primary source of heat for the whole house, I thought we might need something a bit bigger. The Panasonics big brother (CS-HE12GKE) could do 4.8kW at a COP of 4.6 and I was really keen on getting the most efficient one but our Fujitsu strikes the best balance of power and efficiency and has some cool extra features such as being able to press a button and it cleans the primary air filter itself (it slowly moves over brushes, out of and back into the housing). It took a lot of reading to decide on this model and I can now say that I am very happy with it.

It's just so effortless! No lugging around firewood, chopping kindling, catching spiders and slaters from the wood, worrying about the woodpile getting smaller or being wet or falling over onto someone. No more waiting for hours for the inefficient fireplace to exhale enough warm air so that the temperature slowly crept up (did I mention that our previous fireplace was cr@p?) No, I just push some buttons and, voila, the house is comfortable! The other day I had turned it off at night and it was a little cool in the morning (about 15 degreesC) so I turned on the high power option and in LESS than 10 minutes the room was toasty warm! I could actually watch the thermometer going up. Fan tastic! It can output up to 9.1kW in high power mode.

When I first turned it on it was so comfortable I just didn't turn it off again for a week! Currently I'm trying different things such as setting the "on" timer for 7am in the morning and leaving it off at night to save power. Since it heats up the room so quickly it's fine in the morning although when it runs through the night the warmth does travel up the hallway a bit and into our bedrooms. I now want a heat transfer system to circulate the warm air from the lounge into our bedrooms. I'm convinced that it can heat the whole house with such a setup. On cold winter days it may work throughout the night to do so but once the house is warm to start with it only needs to heat for the heat losses and I think that it will be able to handle that with no problems. Particularly once the underfloor insulation and ceiling insulation top up are put in.

One of the things I was concerned about was potential thermal layering of the air. So where there is hot air by the ceiling and cold air by the floor. One of the installers giving us a quote warned us about that and was keen to sell us a (much less efficient Daikin) floor console because as he said "hot air rises". Well I can lay that myth to rest. I have had no noticeable thermal layering at all and even whan I move my hand around trying to test the temperature at different heights, I can only feel a small temperature difference between high and low. So that's not a problem at all. There is a lot of misinformation and urban myths that these so called expert installers tell us.

I recommend this heat pump to anyone!
Benjamin

Living in the new house

It's been a while without a post and the initial excitement has worn off but I'll update this from time to time. Currently I'm working, looking after my heavily pregnant wife and my three children and writing my PhD so I'm rather busy...

So we've been in the new house for a while now and we've come through winter allright although it did get very cold at times. When the house is around 10degC in the mornings it's pretty miserable getting up to that and having only oil column heaters is not great since it takes a long time to heat up. I've done a combination of leaving the heaters riunning low all night, running via a thermostat in the wee boys room an using a timer to turn the lounge heater on early in the mornings but even that only takes the chill off the air really. We have had a shocking (pun not intended!) power bill in the first 2 months so I was more frugal after that.
The new house is definitely easier to heat than our previous house and we do have some uneven loose fill rockwool insulation in the ceiling but I think the main reason is that it is simply smaller.

So progress so far is:
- the fireplace has been covered up and one exterior wall of our lounge has been insulated and gib board (= sheetrock) replaced. I was a bit gung ho about it and bought R2.6 fibreglass blanket insulation (polygold) to put in the walls. It was cheap and I could cut it to size and it was high R so I though it would be good. The 90mm thick R2.5 wall biscuits are about double the price. This is 110mm thick for a wall cavity of about 90mm so the gib board needed to be pushed in firmly to screw it in place and in hindsight I'd probably go for the thinner stuff next time. There IS a little bit of bulging going on in the gib board but I'm not too worried. I took the opportunity to also extend a power circuit to the end of the room with dual 4-way power sockets and also put in a proper aerial socket rather than the cord coming out of the wall... Previously the whole lounge had one double socket at one end of the room which just doesn't cut it nowadays.
- We have a heat pump!!! Yay! Will write a separate post on this.
- insulation has still not been done and the bloody government has pulled the plug on our insulation guys funding because the scheme was too successful and they moved to limit the number of houses insulated . Stupid and annoying for us. Currently there's only one installer who can do work for community services card holders like us so we'll have to re-apply to them and may well have to spend much more money because they are not as cheap... I'm pretty annoyed about it.
- the weather is getting better which is nice.

Cheers!
Benjamin