subject: Heat Pumps (Do They Do What we Really Want?) and Ventilation Systems [print this page] Heat Pumps (Do They Do What we Really Want?) and Ventilation Systems
Sometimes known as
Air Conditioners and HRV's, ERV's and PPV's
Heat pumps are very good heaters and in some cases coolers but do they do what we really want or what we really need? You may think all you need is heating or cooling - but is your house too damp and really needs drying out, which will make your home easier to heat and healthier to live in.
Heat pumps will heat the space we are asking it to (if sized correctly), if it is in the lounge and is designed to heat the lounge, it will do that but very little more. If you want to heat the whole house, put a correctly sized ducted system either in the ceiling or under floor.
When a heat pump operates it will either heat or cool the room, along with the air and any moisture in that space. Heating a dry room or house is much easier, far quicker and far more cost effective than heating a damp room. A damp room or house will take a long time to heat up, and then cool very quickly, causing you to continuously heat with possibly a high energy bill.
If your house is damp, or has condensation issues, installing a heat pump will not cure these problems, in fact, in the short term it could make them worse. As the Heat pump is heating your room/house, the heat will draw moisture out of the fabrics, furnishings carpets etc and allow it to float giving you a humid (or high R/H - Relative Humidity) room, when the heat pump is turned off, the room cools and the moisture falls out of the air, back into the carpets and fabrics but also onto the coldest parts of the room, generally the windows, causing even worse condensation than you had before.
This high R/H along with the (now) warmer house gives ideal conditions for the likes of fungi, mould (mold) to grow and dust mites to multiply making your home far more unhealthy than you would like.
We as human beings like to live in comfortable conditions which is generally 18 to 20 Deg C (about 69 to 72 deg F) at about a 50 to 55% R/H, which is comfortable.
When the room we are in is damp, even though the thermometer or thermostat tells us it is 20 Deg C, we feel' cold, causing us to want to turn the heater on' to heat the room, doing this is wasting energy', as it takes far more energy to heat the damp room. Once heated the moisture levels in the room may rise to 75 or even 85% R/H with a room temperature of say 24 Deg C, again making the room unhealthier than it needs to be.
The only way to remedy this situation is to ventilate your home, (preferably) prior to installing a heat pump. Doing this will firstly reduce the R/H in your house by passing fresh, controlled and filtered air through your home. This in turn will make your house more comfortable to live in and reducing the want' to heat it as often, even reducing the requirement for a new heat source.
If you have already installed a heating source, be it a heat pump or central heating, and found you have the problems mentioned above, I would recommend you install a suitable ventilation system, as it will make your home far more comfortable, healthier and more energy efficient.
The following variables are going to have an effect on which ventilation system will be best for your home and family. a) how you use and live in your home; b) the condition, construction type and aspect of your house; c) how you heat, how often and for how many months you heat; d) the location of your home and the relative weather conditions.
