I need to bounce this idea off a few brains.
We live close to the coast (900 meters) and typical Durban area, very humid.
In fact, it's so humid that we need to keep buying de-humidity bags for the cupboards - and we're losing the battle. Mould ( and mildrew on the fabrics ) is a problem, and it even grows on the ceilings - and we have the windows open all day long with good air flow. Not to mention the associated health risks, the typical coastal 'miff' smell that lingers is not good.
So having done a bit of research, I discover that the mould likes cooler areas, with relative humidity (RH) above 50%. This makes sense to me, and can verify this with the cooler winter months being the worst. Our average RH over the last few months is almost always well above 60%.
So logic tells me that the solution is to de-humidify the air, or raise the air temperature ( which will lower the RH ).
So I'm presented with a few options :
option 1. continue with the de-humidity bags for the cupboards ( costing about R275 per month ), but this doesn't solve the problem with the ceilings, walls, health, etc.
option 2. install air-cons in the house and keep the windows closed, and circulate the air from the room through the cupboards. Very costly solution, and this would mean running the aircon just to cool the room, purely to make the air-con de-humidify the air - not a great idea in winter. Also very high initial cost for multiple air-con units, and running costs.
option 3. this is a DIY project and I would be interested to hear any pro's or con's you can think of :
I want to install a de-humidifer / cooling / heating (DCH) unit in the garage. The floor of the garage is level with the top of the house walls, so piping over the 2 meter distance to the house should be simple.
The DCH will be connected to 2 pipes - inlet and outlet. The pipes to/from the house will be the same diameter as the round gutter down pipes, so assembly in the ceiling should be easy - PVC weld and all standard fittings.
The inlet & outlet from the DCH will go via the piping to each room in the house. At the end of each branch that leads to each room, will be a butterfly valve in the pipe.
A valve will also be in the return pipe from the room to the DCH inlet. My logic on this, is using a microcontroller (MC) ( which I already have ) connected to a humidity and temperature sensor in each room. The MC will then detect the temp & RH in each room, and open the in/out valves for that specific room as required. The MC can also be programmed to automatically turn on / off the DCH unit, so it only runs when required. Also, the MC knows when the rooms windows are open ( via magnetic window contacts for the alarm system ) and would bypass that room if they are opened.
In addition, the MC also registers temperature for each room. So with this info, I can set a 'preferred temperature' (PT) for each room. If the temp is below the PT, then the DCH unit will re-direct the cooled and de-humidified air, past the warm cooling fins of the DCH unit, which will then send warmer dry air back to the room. If the temp is above the PT, then the DCH cools and de-humidifies, and returns the cooler dry air to the room.
A blower fan will be connected to the inlet and outlet pipes to push / suck air in-out the inlet / outlet pipes.
Does anyone see any potential problems with this design ?