Monday, August 20, 2012

Getting Closer to smaller living: Stage 1.7 - Ventilation

Ventilation.  This is HIGHLY important in any home, and triple important in a micro home.   You need to change the air,  draw out spells and moisture from cooking, as well as the bathroom moisture and smells.    Problem is your choices in a micro home are limited,  Full sized home vent fans are far too large for a micro home, and they require 110Vac to run.  If you are planning on being off grid, this is a problem.  They also will draw more air than you really want for the smaller spaces.   yes a bathroom fan that will suck all the air volume that the house has every 5 seconds would be great on bean chili night.  but it will be really noisy and difficult to install in a smaller space.   RV vent fans are another option,  they are designed for smaller spaces, but are horribly expensive for what they are.    My vent fan of choice is the boat bilge blower.

These fans are very small and easily ducted to where they are quieter and they run on 12 volts using a small amount of power.  you can use one in the bath to vent the bathroom,   one in the kitchen, and another at the peak of the house to draw hot air outside during the summer. The nice part is that you can mount all of them in one location where they are screwed to blocks of rubber to isolate the noise and vibration and are accessible for easy servicing.  If you put a filter or filter material over the intake inside the home, you can make sure the fans don't get caked with dust and lint, as well as keeping he ductwork clean.  the duct can be PVC pipe or flexible pipe.  Most of these fans will move 240CFM or cubic feet of air a minute.   240 CFM is a 6 foot by 6 foot by 6 foot cube of space.   Meaning one of these fans will change over ALL the air in a 12X24 micro home every 4 to 5 minutes.   That's plenty!

Now If you think about this,   you don't need a LOT of fans.   one in the bathroom and placing the kitchen outside the bathroom will take care of moisture and smells.   The problem with kitchen cooking is having a real vent hood that will take smoke out and handle the high heat of cooking.   This is where a RV store will come in handy.   I strongly suggest getting a steel or stainless RV stove vent hood and fan and putting it in your kitchen.  over the stove is best, but if you are only going to have a hot plate, then where you will cook with the hot plate is a good idea.    Yes it takes precious space,  but if you have a kitchen mishap, it's nice to be able to draw all the smoke out fast and not worry about the vent hood.

Consider a hot summer day,  if you fired up the loft vent fan and opened the windows in the house on the opposite side of the loft ladder, you will have a constant breeze coming in of cooler air. from the windows.

but let's get clever.  if we had controlled vents UNDER the house that drew air from near the ground outside,  we would draw in even cooler air into the home.   This is why a lot of old homes  had basement windows.  you open the upstairs attic windows, open the doors to the attic and basement and then open the basement windows.   Hot air leaves the roof while drawing in the coolest air from near the ground.  You can cool a house significantly this way.  It will feel cooler than what it feels like outside.   Even cooler if you are in a shaded area and are pulling air from a shaded grassy area.

Problem is you will need air filters to keep dust from coming in the house, just cut some filter material and stick it over the vent holes or roll up some and stuff it in the pipe.  check it and clean it often, every couple of months, just like your home furnace filter.

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