[Ness]

Hi everyone,

we recently got an oil column heater for our bedroom, in anticipation/recognition of colder temps here in ChCh and soon-to-hatch kiwi baby. This is our first winter here. We're in a rental that seems pretty poorly insulated, and there's a heat pump in the lounge, but it definitely doesn't reach the bedroom.

Someone told us that it's cheaper to keep the heater's thermostat on the lowest setting all day/night, rather than turning it on/off every evening, so it doesn't have to work as hard to warm up the room when we're in it. Is this true? It seems a bit counter-intuitive to me, and I haven't been able to find any comparisons for this kind of situation.

Thanks for any advice/insight!

[YouMeAndThree]

It's something I've heard too.

The only comparisons I've seen were based on central heating in the UK - a digital thermostat was found to be more effective left on constantly than having the heating coming on and off during different times of day.

[Familyofmonkeys]

I might be wrong here, but I think that a heater set on thermostat would only really work effectively if you are in a well insulated house that can maintain the temperature reasonably well so 'top up' costs are minimal. In a poorly insulated house (i.e. our first rental) we found the heat is all lost within an hour when the heater turned off and back to brrrrrr..........so you are best only heating the room you are using, if you don't want a ridiculous power bill.

[bob_the_engineer]

the most important thing you can do is dehumidify the place, the energy needed to heat damp air is extraordinary.

just to keep you on your toes, the air has to be warm for the dehumidifier to work efficiently, but the dehumidifier has to be in a cool place, lol does that help?

seriously the dehumidifier has a cold element that draws the water out of warm air, so don't place the dehumidifier close to a heater.

keeping an oil filled radiator running on low without a dehumidifier won't save you money, relative to turning it off, because you will constantly pour energy into the water thats in the air, and the air temperature wont go up (the SHC of water is big).

an oil heater at one side of the room and a dehumidifier at the other will warm the room efficiently.
Oh and running a dehumidifier in a room with a heat pump will save you a small fortune in electricity bills.

Bob

[Ness]

Thanks for the info/advice!

We'd been looking at buying a dehumidifier, but deterred by their relatively high cost -sounds like they're a good investment though.

Thanks again!

[Georgebulldog]

Some great info here, thanks
I'm constantly trying to heat then get rid of condensation.
A quick question, is it OK to have the windows open a little to get rid of the condensation & run a dehumidifier in the same room?

Ness if your going to buy a dehumidifier go for broke on them, we bought one but I wish I paid a bit more & got a bigger one, one on wheels as it's only little but sooo heavy to lift & the lead on it is so short I need to get an extention so it can sit on the landing & do all the upstairs not just sit in one room

[jeffanar]

the most important thing you can do is dehumidify the place, the energy needed to heat damp air is extraordinary.

just to keep you on your toes, the air has to be warm for the dehumidifier to work efficiently, but the dehumidifier has to be in a cool place, lol does that help?

seriously the dehumidifier has a cold element that draws the water out of warm air, so don't place the dehumidifier close to a heater.

keeping an oil filled radiator running on low without a dehumidifier won't save you money, relative to turning it off, because you will constantly pour energy into the water thats in the air, and the air temperature wont go up (the SHC of water is big).

an oil heater at one side of the room and a dehumidifier at the other will warm the room efficiently.
Oh and running a dehumidifier in a room with a heat pump will save you a small fortune in electricity bills.

Bob

Great "engineering" response :nice1

[mylesdw]

Some great info here, thanks
I'm constantly trying to heat then get rid of condensation.
A quick question, is it OK to have the windows open a little to get rid of the condensation & run a dehumidifier in the same room?


No, keep the windows shut otherwise the DH will be running overtime trying to dry the damp air from outside. The only exception would be in the rare case where the outside air is dry enough anyway in which case turn the DH off and open the windows.

[Georgebulldog]

Thanks
So does opening the windows get rid of any condensation? Without the use of a DH do you think? I thought it worked but now I'm begining to wonder :confused:

[mylesdw]

If the outside air is drier than the inside air (which it normally is) then opening the windows works well except that it lets the room heat out too. When it's cold outside keep the windows shut and run the DH. As others have already mentioned they make a huge difference to the feeling of warmth in the house and are not very expensive to run.

[Georgebulldog]

Thanks, answered my next question too which was going to be how much is a DH to run
Think I'll close the windows then on a day like today when it's raining on & off, saying that sat here with the sun on me now & it's warm, just to add to the confusuin even more :)

[Familyofmonkeys]

Dehumidifiers are not cheap to run......but you will save more money on heating than you spend running the dehumidifier so they are a definitely worth the investment in this kind of climate/housing. Plus it makes your living environment much healthier and more comfortable as it reduces the amount of mould spores/dust mites etc that you get when the air is damp.

[Georgebulldog]

It's mould that we have on the window frames, washing them at the weekend with some spray I bought. Paranoid about these & asthma, 1 in 4 kiwi kids it says has it & I don't want mine to be one of them
I feel like I'm constantly running around opening windows, closing curtains, trying to keep the heat in then get rid of the condensation. Do you think there will come a time when I get the right balance?

[Familyofmonkeys]

It's mould that we have on the window frames, washing them at the weekend with some spray I bought. Paranoid about these & asthma, 1 in 4 kiwi kids it says has it & I don't want mine to be one of them
I feel like I'm constantly running around opening windows, closing curtains, trying to keep the heat in then get rid of the condensation. Do you think there will come a time when I get the right balance?

I'm asthmatic, and after the initial couple of months in our first damp uninsulated rental, we managed to get to grips with many of the risk factors for asthma.......my kids are all at high risk due to family history and allergies.

Just remember things like maintaining a bedroom temperature of 18 degrees at night (and certainly never below 16 degrees), wash bedding, towels and other soft furnishings like curtains regularly at 60 degrees to kill off dust mites and get them cleaned straight away if they show signs of mould or mildew. Use mattress protector covers to protect the mattress from absorbing moisture from your body at night as it reduces the likelihood of it containing lots of mould spores and dust mites. Wash duvets and pillows regularly and make sure they are completely dry before storing or using them. Carpet fabric holds lots of moisture and other nasties so try to keep it dry and never get it cleaned in cool damp weather when you can't ventilate it and get it completely dry......solid floors with removable rugs are a better option if you have the choice. Always use an extractor when cooking, especially if you have a gas hob......even for boiling the kettle.

The list goes on really.....but it helps to be aware of this stuff even if you're not asthmatic as some simple changes can keep your home a lot healthier :)

[blackcat09]

Our heat pump has a 'dry' heat setting. Is that effective?

[Ness]

Our heat pump has a 'dry' heat setting. Is that effective?

Ours does too, and the manual doesn't explain much about it, but it doesn't seem like it'd be as effective as a dehumidifier. Where would all the moisture go?

The asthma stuff really scares me too, given fam history and other risk factors are already there. And yes, it does seem like a full-time job to deal with the effects of poor building standards every day...it's not like the technology hasn't existed for decades. And here I am trying to get mold off the window frames.

Sorry, I don't want to be a whiny recent NZ immigrant, but it is frustrating. Maybe I should enter the lottery so we can build a proper house ourselves.

Thanks for all the engineering tips though!

[barbapapa]

Thanks
So does opening the windows get rid of any condensation? Without the use of a DH do you think? I thought it worked but now I'm begining to wonder :confused:

You may want to consider buying a weather station such as http://www.dse.co.nz/dse.shop/49fa2690002134f6273fc0a87f3b06b6/Product/View/Q5172

They shows humidity levels inside and outside so you kn ow when to open all windows.

[Georgebulldog]

Just want to say a big thank you for all the info on here, I know I've asked before but I think it's a good idea to bring this subject up at this time of year, every year just to remind ourselves until we get into the swing of this being every day life

Babapapa, I WANT one & I WANT one NOW! I love looking at the weather websites, esp the local ones that someones done from their house so this would be an ideal gadget for me but really useful with it, a mothers day pressie maybe, better get on & e mail it to OH :D

[KelvinAng]

I second the suggestion for one of those "weather stations" gadget (not just because I love gadgets!). I realised, after having one of those gadgets, that I can't tell the difference by feel whether it's 30% or 80% relative humidity so it certain helps suggest when I should turn on the dehumidier (especially since I got a cheapie that doesn't have a built-in hygrometer or "thermostat" type control).

[bob_the_engineer]

Great "engineering" response :nice1

:laugh I know I'm a sad man....

The best dehumidifier I've found (I now have 3) is quite a cheep one. Its called somthing like SUKI its a 35 L (thats the flow not the capacity an 35 is way up there) it costs about $350 from mitre 10 and the bad ones leak!

Stand it on a sheet of newspaper and run it for a few hours, if it dosn't leak in the first 8 hours it will be fine.:nice1

Oh mitre 10 also do a 15L one for about $150 its good value but makes a lot of noise.

Bob

[YouMeAndThree]

:laugh I know I'm a sad man....

The best dehumidifier I've found (I now have 3) is quite a cheep one. Its called somthing like SUKI its a 35 L (thats the flow not the capacity an 35 is way up there) it costs about $350 from mitre 10 and the bad ones leak!

Stand it on a sheet of newspaper and run it for a few hours, if it dosn't leak in the first 8 hours it will be fine.:nice1

Oh mitre 10 also do a 15L one for about $150 its good value but makes a lot of noise.

Bob

We've just got a 16L (per day) Suki dehumidifier from Bunnings - cheap and on a whim, for $198. I don't think we have a particularly damp house, but it's surprising how much water is being collected. Maybe when we have our own place we'll splash out on something a bit better, but it's doing it's job (or at least a fair job) atm.

[thewoodies]

Just stumbled upon this thread! I have bought my old dehumidifier from the UK but hadnt thought about using it ! What a great idea to save on heating will give4 it a go thanks !!:nice1

[DizzyF]

We have just bought a house which has a HRV system. Does anyone know if this does the work of a dehumidifier or should we be using a dehumidifier too. The only heating we will have will be oil fin heaters and i am dreading my first NZ winter...especially as we are expecting a baby in 6 weeks.

[Yer'wan]

Technically speaking, No. HRV is designed to provide ventilation in well insulated homes incorporating a well installed vapour barrier. Basically it extracts warm/stale air from inside (which will have a percentage of moisture in it) from your house, and draws in cold/fresh air (plus moisture) from outside, the heat which you would of lost is transfered back into your home. The levels of moisture inside would not be changed if the %RH were the same inside/outside. If you're concerned with the moisture levels, I would recommend purchasing a Thermo/Hyrgrometer to keep check of these levels and only use the de-humidifier if you need to keep the RH down.
Hope this answers your question.

[Yer'wan]

If you have nothing interesting to do.....

http://learningstore.uwex.edu/pdf/B3783.pdf

[Wooly_Cow]

If you have nothing interesting to do.....

http://learningstore.uwex.edu/pdf/B3783.pdf

Interesting article in terms of the definitons however the recommended Relative Humidity of between 30-40% in winter is a figure for the US and not NZ. In NZ the normal outside ambient humidity is between 70-80% on the coasts and about 10% less inland. Equally people should feel comfortable at temperatures from about 18-24c and humidity of 30-80%.