Tag Archives: indoor air quality (IAQ)

Lacquering what I like

The paint has come off, and now needs to get back on. Although it won’t be paint – it will be clear, VOC free lacquer.

Having gone through a couple of tubes of wood putty and many sheets of sandpaper, I was ready to dust off the vertical trim and start lacquering.

Two coats, with a drying time of six to eight hours between each coat. The lacquer brings out the beautiful warm white oak color and adds a nice sheen to the trim.

I stay mindful about our health and safety as well as the immediate and long term indoor air quality (IAQ) and kept using the VOC free Acrylacq by SafeCoat. No solvents, no nasty fumes or smells. Why would I ever want to use the conventional, VOC based paint products?

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Range hood recap

What is there to a range hood? Well, it depends on how deep you want to dig.

In simple terms: You want a functioning range hood over your stove to dump cooking odors and moisture to the outside. It helps a long way with maintaining good indoor air quality (IAQ). Who really enjoys smelling the cooking from a few days ago across the house or wiping the cooking grease film off of the living room furniture?

But simple is boring! The nuances that surround the range hood are much more interesting.

Nuance heaven

I mentioned it, and I’ll say it again: Be picky about the ventilation rate!

Logic suggests that a hood with a high ventilation capacity would be more effective in exhausting cooking odors. But it wouldn’t necessarily be efficient. How much airflow would it really take? Any additional flow beyond that represents wasted electricity.

Widely referenced residential ventilation rates can be found in the ASHREA Standard 62.2. The minimum required exhaust rate for user operated range hoods is listed at 100 cubic feet per minute (cfm). The standard was published back in 2003. I expect that it will be updated considering the increasing emphasis on reducing air leakage in buildings.

Our freshly installed hood has two ventilation settings – 100 cfm on low and 250 cfm on high. There should be a balance between the amount of air exhausted to the outside and the makeup air.

High capacity range hoods (starting at 600 cfm) may throw that balance off and begin to depressurize the building, which can cause a number of problems.

Take open combustion appliances, such as a water heater for instance. With the high capacity range hood cranking at full speed, the exhaust fumes from the water heater may backdraft into the building.

Or – during the summer months – a high capacity range hood may be the culprit for hot and moisture laden air leaking into the building. If the building is air conditioned, interstitial condensation forms on the cooler interior surfaces, which can lead to mold problems.

Options, options, options…

Have you seen those range hoods that ventilate back into the building? They are the preferred option in some particularly airtight Passiv Haus buildings. A charcoal filter in the hood should eliminating the cooking odors – as long as it is regularly replaced.

Suppose we are on top of the filter maintenance. We still haven’t addressed the additional moisture load from the cooking.

Let’s ventilate to the outside instead and think about managing the makeup air. Opening the kitchen window a crack while the range hood is operating would be an option. Other folks borrow from commercial kitchen design, and install a fresh air supply duct that terminates near the stove.

Either option carries an energy penalty: Introducing unconditioned air into the conditioned building interior. This may be less of a problem in the winter when heat generated from the cooking may somewhat lessen the energy loss. During summer, however, the make up air would be hot and humid and one can start to count the energy penalty in sweat beads.

Why hasn’t anyone come up with a heat exchanger for range hoods, similar to the Heat or  Energy Recovery Ventilators (HRV’s or ERV’s)? The engineering challenge lies in the cooking grease.

Read ERV or HRV installation manuals, and you are instructed not to install an exhaust in the kitchen. The cooking grease will ruin the heat exchanger, or at a minimum shorten its lifespan.

Should we grease up some sharp minds and try to solve this fat engineering challenge? Even if we do, the grease removal or management would likely require additional energy input. That flies in the face of the energy reduction goal.

Going back in history to a time where energy or electricity was precious can be enlightening. Jeremy Spates, who studies historic preservation at the School of the Art Institute of Chicago, pointed out that “especially in Chicago, cooking was probably done with coal or wood in an iron stove, but with a smaller blaze than one might use in winter”.

Larger houses had the kitchens in the back or the basement, such as the Clark House. I only can speculate to what extent this may have reduced the heat gain from summer cooking.

Jeremy also pointed out that outside the urban environment, some houses (or mansions) in the eighteenth and nineteenth centuries had outdoor kitchens where the summer cooking took place, thus keeping the extra heat out of the main building.

Now here is a good idea – simple yet effective, and may be more suitable for energy efficient buildings than we realize.

The concept

Kitchens are difficult to manage in airtight homes. Why shouldn’t we place the kitchen outside the airtight envelope – at least on a seasonal basis. It would address the excessive heat gain, moisture load and makeup air issue. It would solve a big headache.

This idea has been lingering for a while and our back porch has come up as a potential space where we could conduct our summer cooking. The deeper we get into the summer, the more I warm up to the idea and I am increasingly glad that we extended the gas line into the back porch – just in case we decide one day that summer cooking on the porch is the cool thing to do.

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Chasing after a star – Energy Star for a range hood

When preparing a blog post, I often ask myself: “What would be a one sentence summary”? For this post, I can boil it down to one word: Tenacity!

During my indoor air quality (IAQ) research, I learned about the importance of picking the right range hood:

  • The range hood is critical for moisture management and IAQ.
  • One has to be careful not to over-ventilate in tight homes – i.e. depressurize the building.
  • A ventilation capacity of 150 cfm is recommended for tight homes.
  • Stay away from powerful downdraft range hoods (600 to 1200 cfm).
  • Exhaust the range hood, and with it the moisture from cooking, to the outside.
  • Use an energy efficient, preferably Energy Star certified product.

See also:

It is that last item that required my tenacity – procuring an Energy Star certified product.

By looking at the various products, it is easy to conclude that a sleek design is what sells a range hood. Efficiency is really not much of a focus or selling point.

The Energy Star product list provides a refreshing departure from the sleek status quo. Here one can indulge in rows of energy efficient models. Although, after the first enthusiasm passed, the typical energy rating of 3.8 cfm/watt seemed disappointing.

Imagine my surprise back in 2011 when I read 8.6 cfm/watt. A Whirlpool range hood had appeared on the Energy Star list, and it promised to move air with a lot less electricity.

Fast forward a few months. The promising model disappeared from the Energy Star product list. I thought it would be wise to double check the product’s energy efficiency rating and searched the web – no luck. Was this one of those “too good to be true” cases?

When I called Whirlpool, no one seemed to be able to get their hands on the range hood’s energy efficiency rating either. One customer service agent finally revealed that the model had been discontinued. Oh my!

Back to 3.8 cfm/watt? I was left scratching my head.

Coming up with energy efficient range hoods can’t be rocket science! Great advances have been made in the development of extremely efficient ventilation motors. Just look at some of the current ERV and HRV products. Why do these advances not translate into the field of range hoods?

I kept checking the Energy Star product list every other month – and bingo! AirKing has a new model (Essence EB series) listed with 5.4 – 6.7 cfm/watt at an airflow of 107 – 132cfm. That is quite an improvement over the ESDQ AirKing model we used in the garden unit (3.8 – 4.0 cfm/watt at an airflow of 159 – 163 cfm).

Let’s buy it! But where? It was nowhere to be found … not among the online retailers, or even on AirKing’s web page.

It was time to pick up the phone. A call to AirKing in November, 2012 revealed that the new model was scheduled to hit the market in February 2013.

But why was it on the Energy Star product list months prior to that? AirKing submitted a prototype to Energy Star for testing and certification. Once certified, it made it onto the Energy Star product list. But AirKing still had to get ready for production.

This doesn’t make it easy for the consumer; it’s confusing and requires tenacity. I could afford to spend the time on tracking the products and wait this out. But what about other buyers?

I finally placed my order for range hood AirKing Essence EB at the end of April 2013, with a lead time of 10 days. Manufacturing was still ratcheting up.

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1st floor kitchen counter top installation

We got our salvaged and freshly fabricated stone counter tops safely from the truck into the house.

The first thing I wanted to do is to place them on the kitchen cabinets to see if we got all the dimensions right – and we did! That was a weight off my shoulders.

It also meant that we could start with the counter top installation in earnest – which is relatively simple, except for the large piece that will hold the corner sink.

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I needed to cut the opening for the sink out of the plywood base. While we test placed the counter top pieces, I traced the triangular corner cuts for the sink onto the plywood. That took out all the guess work and gave me an accurate cut out location.

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The looming question was though: Did we get the sink dimensions right and would it fit? We lifted the sink in place – and indeed it did fit.

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The next step was to install the large counter top piece for good. We used VOC free construction adhesive to fasten the stone to the plywood base. During the placement we made sure that the triangular corner cuts still lined up the cut out in the plywood below.

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Time to get the angle grinder and shop vacuum out! After a few carefully cuts from one corner the the next, we had our sink opening in the counter top.

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Another test placement of the kitchen sink confirmed that we also got these dimensions right.

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With that out the way, I focused my attention on the installation of other pieces and on sealing the stone, including the back splash.

Limestone is notoriously porous, which is sort of a problem. For hygienic reasons, a counter top should be impervious and easy to wipe down and clean. We found a low VOC stone sealant that met our indoor air quality (IAQ) standards.

With the last coat of sealant cured, I could start installing the backsplash pieces. To attached them I used a bead of silicon to the counter top and the cement wall board. The silicon will also prevent any water from escaping behind the counter top and down the cabinets.

The timelapse below shows the entire installation sequence. Enjoy!

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Painting, equipment and sidetracking

Thanks to our friends Scott and Carlos, priming the drywall was like eating cake! And – because we got the priming done so quickly – I now can shift gears and start with the proper paint.

While looking for a suitable zero VOC paint product, I ran again into the issue of finding something that has a price point of $30/gallon or less and is not a special order.

After some back and forth, we settled on Behr Premium Plus Interior Eggshell Enamel. It meets our price point and zero VOC requirement, and is labeled low odor.

I found out that low odor does not mean odor free. Don’t get me wrong – it is not obnoxious. In fact, it is really nice to paint without being engulfed in the fumes of other conventional paints that still contain some level of volatile organic compounds (VOC’s). But, as I said, it is not odor free.

While I was in the store, waiting for the color to get mixed, I browsed through the various rollers that were on display. I picked up a rather pricy one to give it a try.

To my surprise, it lasted through the entire paint job, and it still in such good shape that I probably will use it on the second floor. Compare that to the cheap rollers I started with. They lasted for one day and had to go into the trash.

That got me thinking – about the trash we produce because we fall for a lot of cheap stuff. Plus, economically it made sense to get the expensive but good quality roller. By now it has paid for itself, outlasting God knows how many cheap rollers.

It is also a microcosm of what happens with green buildings and deep energy retrofits like ours. A lot of people shy away from the green or more energy efficient option because it appears so expensive when compared the the conventional (cheap) options.

But if green building technologies are executed wisely, they begin to pay for themselves – and may even begin to save some real money at the end.

Wow, I really had a lot to say about painting – didn’t I?