Giving you the information you need to improve the safety, comfort and value of your living space. .

What sucks in, must blow out!

4 Oct 2013 | No Comments | posted by Lisa | in All-Technical, Ventilation

WHEN you turn on that bathroom  fan, you want to get rid of odours FAST. If the fan sounds loud and the smell dissipates – end of story – right? But do you check the other end of the pipe? During my home inspections in the Toronto area, I try to at least verify that suction is effective, and FIND the other end of the pipe.

One really important function of fans is to push stale and moist air from inside to out. The exhaust end must vent all the way to the outside of the house, and be dedicated to one duct only. Here’s some cases when it doesn’t and why that’s a bad thing;

• Venting into attic, ceiling or wall space – puts moist air into a confined space which can cause mold and deteriorate roof structure. Sometimes you can see the duct ends inside the attic. A clue to a problem, even if you can’t see a duct venting in here, is lots of spider webs. A dry, well vented attic actually has very few spider webs visible. Moisture attracts bugs, and in turn other critters.
• Connected to plumbing waste stack vent – an unprofessional shortcut. The waste vent carries sewer gasses, and these can backdraft into your fan ducting, causing smells, corrosion/leaking and possibly electrical/fire hazard.
• Connected to another fan duct – laundry or kitchen. Again, not good – air can go back down into the other room in the right conditions.

The fan duct may terminate on the roof, through the soffit (not ideal) or through the wall. The ideal configuration depends on the location and type of house structure.

The first step a homeowner can do to see how their stuff works is to check the fan’s suction by putting a piece of paper against the grill in the ceiling while the fan is on. The air suction should be able to at least hold the paper against the grill by itself. Now close the bathroom door and window – is the fan pulling air under the door into the room? This is how it should be. If you can’t detect a strong airflow with these methods, it’s not working right.

The second step is to locate the exhaust on the outside of the house. You should be able to match each fan, if more than one, with each exhaust port.

Make sure the inside grill and exterior exhaust hood are clean and free of debris or blockages. Look inside from both ends.

Sometimes on a really cold day, if you are venting from a warm humid bathroom, you will see the vapour coming out the exhaust. If the discharge point is reachable from the ground, you may be able to feel the airflow with your hand. For higher vents, you can check from a ladder.

If you have a clear intake and exhaust but you are not getting good airflow from inside to outside, there could be problems with the ducting between them (too long, kinked, blocked, open joints).

If you can tell air is being sucked from the inside but you can’t tell where it is going, there are various devices for generating a visible smoke for visual testing. Test matches, puffer sticks, smoke candles, smoke bottles, etc.

A little bit of investigation of your fans can go along way to preventing major damage in your house. If it’s not working right, have it professionally fixed – and check it after it’s been done.

Does Your Home Suck? Keep it Fresh!

28 Aug 2013 | No Comments | posted by Lisa | in All-Technical, Ventilation

VENTILATION – How to Breathe Easy in your Home.

Most people don’t think about the air pressure in their house, or more accurately, the difference in pressure within the house  relative to the outdoors. But pressure affects airflow and the movement of dust, moisture, gases, and smells; in other words, your indoor air quality (IAQ).

You, the resident, have the most to lose or gain in controlling airflow in your house or condo. Become your home’s expert – learn how the air moves around your home !

Between 1986-1990 many new homes were built with increased vapour/air tightness, however due to the lack of understanding at the time, ventilation to compensate for the tightness was not put in.

Lower air pressure in the house relative to the outdoors can promote incomplete combustion of gas/wood burning appliances (furnace, water heater, fireplace) therefore carbon monoxide levels could be a concern.  

Areas of your house with very little air circulation can allow excess humidity to form which can lead to mold.

         TAKE INVENTORY

Go through your house and make a list of air controls using the AIRCHART table below as a starter guide.

As you walk through, check to see if kitchen fans actually discharge indoor air to the outside or do they just pull it through a filter and blow back into the kitchen. 

Check the suction of a fan or return duct by putting an 8.5 x11 piece of paper on the grill. Locate exhausts on the outside and check for signs of air movement. 

Do you have an HRV(Heat Recovery Ventilator)? Most new houses come with one. Read the manual and learn how to use the controls and clean the filters.

If you have a forced air furnace/central air, figure out which registers are pushing air into the room and which ones are pulling air back to the furnace (“returns”). Airflow in these registers or ducts can often be adjusted with dampers they come equipped with for temperature comfort. Ensure furniture does not block any grilles.

See also my article about changing filters.

Air Chart

Unless you have an HRV (Heat Recovery Ventilator), if you have fans that exhaust only – the house SUCKS!

HOW DO I MANAGE MY AIR – FANS and WINDOWS

In areas where you make smells and moisture – if you have a fan, USE IT!   

If any part of the house gets stale or stuffy, open windows on different levels and different sides of the houses to get a breeze going through.    This is called cross ventilation, and  is most useful during spring and fall when you are less likely to have the heat or cooling on to blow air around the house.   You will find through experience that certain windows or combinations of windows will vent better than others.   

During one of my home inspections, I will walk around with you to show you how the ventilation systems work, point out any problems or concerns, and my report will have more background information for you.

Maximize your comfort by managing your airflow – MAKE YOUR HOUSE BREAK WIND!