Category: Heat Pumps

What the Heck is an ICF?

2/20/2022

While preparing for a potential power outage recently due to freezing rain, I couldn’t help but notice this radio as inspiration for writing my next blog post. You would likely think I am going to talk about emergency preparedness, but I am looking at the model number, particularly the first three letters, which as you can see are ICF.

Yes, this is a radio in a blog post that has nothing to do with them.

In the world of home construction, ICF is an initialism for Insulated Concrete Forms. While it has only become common in the past 15 years it actually dates back to its invention right here in Canada in 1966. An ICF is composed of two main components: insulation, almost always in the form of expanded polystyrene (EPS) and concrete with steel reinforcement (rebar). They can be used in both foundations and walls, although the latter is less common. The insulated blocks are used to hold the concrete while it cures (just like the removable plywood used in regular concrete construction) and are permanently left in place to provide valuable wall insulation.

The first time I saw one in 2007, I thought it looked like someone enjoyed Lego a little too much!

I recently did an inspection where the buyer wanted to know what an ICF was and how far it went up the walls. While I typically see them just used as the home’s foundation, this particular home inspection showed that the entire wall structure right up to the rafters was constructed of ICF. So, is that a good thing? The cliché answer is that it depends. My professional answer is an absolute yes, but it definitely has drawbacks.

First, the Bad News
There are a number of disadvantages to ICF construction. Some of these include:

ICF houses cost more to construct. Estimates are between a 6-10% increase in construction costs over a wood framed house, although with the recent increases in the price of lumber this gap has likely lowered and will continue to do so.
ICF houses are more difficult to renovate. While I complain constantly about how the various home improvement shows make it look far easier than it is, ICF takes it to another level. It is more challenging to install new plumbing and electrical and it is almost impossible to add new windows, doors, etc. at a reasonable cost to an ICF home.
All concrete releases large amounts of moisture when curing, which is why finishing a basement in a brand-new home is highly discouraged within the first year. ICF walls will introduce excess humidity to the entire house and extra dehumidification will be necessary, especially during the first summer.
As an inspector, it is very difficult if not impossible to closely inspect ICF foundations. As they are buried behind insulation and a masonry veneer, any cracks or potential structural issues are not immediately apparent. In my experience ICF houses are usually well constructed so this isn’t a major concern, but I do like to be meticulous in my work

Advantages of ICF
There are many benefits to an ICF home. While I only report and never make advice on buying decisions, I definitely get excited when I see ICF construction. Some upsides include:

ICF walls are not only more energy efficient, but they are also great at blocking noise.
ICF houses, in my experience are downright comfortable in the summer. None of the ICF houses I have inspected have permanent air conditioning installed, and that is because they tend to better resist heat movement, either in or out.
ICF materials provide excellent indoor air quality, although like most modern homes they do require mechanical ventilation to remain healthy. The insulation is not toxic and do not contain Volatile Organic Compounds (VOCs).
More rebar is used in ICF construction. Without getting into building science or engineering, concrete is very strong against compressive forces but weak against tension forces, which is why it needs to be reinforced. ICF walls are generally very strong and highly resistant to wind and other forces of nature.

Overall, I draw parallels to my post on heat pumps. While there is a significant initial upfront cost, the savings in both money and energy over the long run make it all the more worthwhile. Unfortunately, the higher price tag can scare many developers and new homeowners off.

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Ductless Mini-Splits

10/17/2021

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Being a homeowner can mean having to make many large financial decisions even after the home has been purchased and the closing costs have finally been paid off. One such major expense I see more homeowners making is installing heat pumps, in particular retrofitting older homes with a ductless mini split system. We completed this task on our home in the winter of 2020 and you may be wondering if it was worth it? My answer is simple: YES!

Let me first mention the drawback, and it is a big one. Costs can vary but $10,000 is a good ballpark estimate for installing a mini-split system. While financing options are available and these units more than make up for it over time in energy savings there is no getting around the fact a significant upfront investment is involved. They are also not very attractive to a home’s decor (some recent models, however, look just like artwork on a wall) and while I have no issue with its appearance, others may not feel the same. As for the benefits, they are many and here are just a few:

Reduction in Heating Bills
The most obvious benefit can be seen in your heating bills, especially if you have an all-electric heating system like we did. Even considering that 2020 was the first winter we had a baby in the home and subsequently turned the heat up all day long, our power bill still dropped by almost 40% during the coldest months! Even in the summer we only went up about 15% and considering the incredible difference in comfort that was a price well worth paying. Given how energy costs are rapidly rising this is also a good buffer against sharp price increases.

Can Run Dual Heating & Cooling Duty
Heat pumps are basically Air Conditioners (or Refrigerators) that can be run in reverse, where the two heat exchangers switch between acting as an evaporator and condenser as the season (or in Nova Scotia, day) changes. As a result, they provide year-round comfort on even the coldest days. Even on those crazy weather days where we go from cold to hot to cold again, they can seamlessly switch between heating and cooling automatically and efficiently.

No Extraordinary Installation
As the name implies, ductless mini-splits do not use air ducts as working with existing ductwork is usually difficult due to density differences between hot and cold air. Side note: I once took a course on air system design and let’s just say it’s best to leave it to the pros! If there is room in the electrical panel then no complicated electrical work is necessary. Even the large amount of moisture removed by the system in the summertime usually drains outside without the need of a drain pan or other maintenance.

Easy to Maintain
While I always recommend an annual checkup by a qualified HVAC (Heating, Ventilation & Air Conditioning) technician, the only maintenance required by homeowners is to regularly clean/change the filters and keep snow and other debris away from the outside unit.

Quiet
Like any appliance with a compressor, heat pumps make varying levels of noise. However, it is almost exclusively made outdoors, well away from the inside of the home. The noise level is comparable to a fan on the lowest setting most of the time and even at its worst it is barely noticeable.

The biggest myth I see about heat pumps is that they are not suitable for cold weather. The fact is some units can operate efficiently right down to about -26C/15F, which is more than adequate for even the coldest days in our Nova Scotia climate. Heat pump technology has grown by leaps and bounds in the last decade and will likely only improve over time. Do I recommend getting a heat pump installed if reasonably possible? You bet!

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Michael Burfitt

What the Heck is an ICF?

Ductless Mini-Splits

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