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What I spent 20 years at is finally starting to catch on with my industry....

fyi - home energy audit costs about $600, full rebate for this if you decide to install new insulation, or new HVAC gear that improves efficiency

And I was in a good position to take advantage of rebates. Townhouse built in 2005, I still had the original furnace and hot water tank, and many other owners in the complex are starting to need furnace repairs and new hot water tanks. It was just a matter of time before I would need to do repairs, so as @TorontoBuilder says, lower cost of ownership
 
whydontu said:
So it costs more money to generate electricity during the day? Is the water in the hydroelectric storage lakes lighter during daylight so it makes less power? This type of artificial pricing drives me nuts.
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I’ve seen electricity pricing maps where during certain times utilities have to pay others to use their electricity. This is primarily nuclear generators that are difficult to quickly reduce power production from.

It’s like a stock market.
 
TorontoBuilder said:
Each case must be done on an individual basis starting with an heat loss and gain calculation of the structure, including with a blower door depressurization test.

I have a detailed fuel cost calculator that compares energy costs, financing costs and the total cost of ownership that I'd typically present to architects, builders and the people having the home built.

In these scenarios the cost comparisons are made based on a host of energy efficiency upgrades to determine how quickly the incremental capital costs are recoupled. I'd typically compare baseline equipment of the minimum efficiency permitted by code, against hybrid system with air source heat pump and back up gas furnace, and against a ultra efficient cold climate heat pump alone.

Because these cases are always based on having a mortgage it always pays to go with the better system. The monthly energy cost savings may not seem huge in some cases, but that cost is always lower than the small increase to the mortgage payment attributed to the incremental cost of the upgraded system, and the upgrade costs typically pay for themselves inside of 5 years, so beyond that the carrying costs for the home decrease even further.

I've not seen a case where it did not pay off, because I am very careful in selecting the equipment choices presented, and I also ensure that the envelop is improved to a point that permit the choice of certain sizes of equipment that are higher efficiency. We design systems that include energy monitoring technology and validate our results and troubleshoot potential issues.

When you finance retrofits you can do similar. But I would never work with clients who wont undertake major building envelop upgrades prior to any HVAC system retrofit.

If you were insterested in an actual case I'd be happy to advise you

of course it is important to note, we are looking at conditions where the current equipment is at or near the end of life cycle... or new construction, so you already have the cost to install a system to bear. So the costs we're looking to recoup very quickly in order to achieve higher long term (~20 yr) cost savings are only the incremental costs.

The other aspect of doing this right is to know and have relationship with contractors who are not part of the "incentives profiteering" aka those who know the purchaser is getting thousands in incentives so they mark up their prices much higher than normal.

Retrofits we'd perform calculations to assure that the incremental cost of financing was financing c
if the incremental cost is recouped within 5 years, and mostly very worth while if the payback is when the systems last 20 - 25 years.
In the case of retrofit
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Thanks for the detailed reply! In my case it would be a replacement of a high efficiency furnace and A/C installed about 10 years ago and still functioning well. I'm confused regarding why the payback time would be reduced by improving insulation. Comments?
 
TorontoBuilder said:
Only 10 years ago I was going to build my retirement home with a large geothermal ground loop system that cost thousands of dollars to install.

Now I can replace that with air source cold climate heat pumps and put the loops in the foundation floor to have radiant floors. Yes I'm pretty high on this tech
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That’s interesting. So are you saying that it is now cheaper overall to use cold climate heat pumps than geothermal ground loops?

We’re about to replace our furnace and I feel bad that we’re going to use a high efficiency gas furnace- solely because I suspect we’ll be moving in a few years. If this was our retirement home I’d have looked into cold climate heat pumps and solar more seriously.
 
kstrauss said:
I'm confused regarding why the payback time would be reduced by improving insulation.
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I think what he means is that each component costs money and they should be assessed on their own merits, not stacked. With insulation, total cost of operating the system goes down so savings go down too. In other words, a system in a poorly insulated building will SAVE YOU MUCH MORE, than one installed in a well insulated building. However, the overall cost savings from both improvements is greater than it would be without. So that represents the lowest cost but not the greatest relative savings. It's double talk. From a practical standpoint you would do both.

Here is a simple analogy. A tiny little car doesn't consume any less fuel than a big SUV if you don't drive anywhere..... LOL!

A fuel pump system can't save you a lot of money if your home doesn't need as much heating or cooling because the insulation was beefed up at the same time.

But you don't care about savings. You care about how much it costs you.
 
kstrauss said:
Thanks for the detailed reply! In my case it would be a replacement of a high efficiency furnace and A/C installed about 10 years ago and still functioning well. I'm confused regarding why the payback time would be reduced by improving insulation. Comments?
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Time for a short primer on the steps to designing efficient HVAC systems.

Improving efficiency of HVAC equipment can only have a minor impact on HVAC operating costs, because efficiency gains are often only in the order of 3-5%. Most of Canada's incentives have only impacted HVAC equipment efficiency gains. On the other hand building envelop improvements can have a major impact and reduce energy demand by upwards of 50% or more, yet the manner in which incentives have been applied have hindered major envelope improvements as homeowners favoured the low hanging fruit of HVAC equipment replacements they intended to do anyway.

A building's heating system must be able to provide enough heat to maintain indoor comfort, even during the coldest outdoor temperature expected in a given location, therefore it is imperative to know the average temperature (.typically the lowest 1% to 3% of temperatures) of the coldest days of the year. This temperature is called the outdoor design temperature.

In Canada, the official source for outdoor design temperature data is the National Building Code of Canada (NBCC) and those Provincial Building Codes which rely on data from the NBCC. The NBCC provides a set of climatic data tables that are based on 30-year weather data collected by Environment and Climate Change Canada (ECCC) recorded over a 30-year period.

HVAC professionals use the outdoor design temperature as a basis for calculations designed to properly size heating equipment, such as boilers or furnaces. A heat loss calculation is a process of estimating the amount of heat energy that is lost from a building through the walls, roof, windows, doors, and other components of its envelope. This calculation is essential for determining the appropriate size of heating equipment, to ensure that they are capable of providing adequate heat output to keep the building comfortable even under extreme weather conditions.

The heat loss calculation takes into account factors such as the building's insulation levels, the size and orientation of its windows, the air infiltration rate, and the thermal properties of its materials. By using this information, HVAC professionals can estimate the rate at which heat is lost from the building, measured in units of energy per unit of time (e.g., BTUs per hour).

Example Case

Lets consider an older building from the 1970 that was built with 2x4 construction and insulated at the time of construction, yet had no real air barrier nor have any serious air infiltration mitigation efforts been made to improve the home. That building may typically have an air infiltration rate of 10 air changes per hour at 50 pascals of depressurization. This number estimates how many times in one hour the entire volume of air within a building will be replaced by outside air at 50 pascals of depressurization. Well what does that mean you ask?

50 pascals of depressurization is typically used to simulate worst-case conditions, such as high winds blowing against the building envelope. The pressure difference of 50 pascals is a standard measurement used in building science and is equivalent to approximately 20 miles per hour (32 kilometers per hour) of wind blowing against the building. Those who live in Canada know how often winter storms are blowing in Canada. It should be no surprise then that the number one component of heat loss from most older structures is due to air infiltration.

Mitigating these losses should have been the number one priority of every incentive program since the 1970s. Yet air infiltration mitigation is difficult, and costly and has always been an afterthought forced on the government by experts.

In this case the home's heat loss of 100,000 BTU/ hour can be reduced by over 50% with a major retrofit. New equipment of half the size can then be installed. Smaller equipment also has the benefit of a lower capital cost, lower financing costs, and quicker payback against larger output equipment. OH and let's leverage those savings further... the heat distribution system can be reduced in size and cost, and it often quieter. The overall energy cost savings in this scenario can be over 60% annually. I've done many homes that mirror this example

Oh and the building will now be more comfortable, quieter, etc etc...
 
Susquatch said:
I think what he means is that each component costs money and they should be assessed on their own merits, not stacked. With insulation, total cost of operating the system goes down so savings go down too. In other words, a system in a poorly insulated building will SAVE YOU MUCH MORE, than one installed in a well insulated building. However, the overall cost savings from both improvements is greater than it would be without. So that represents the lowest cost but not the greatest relative savings. It's double talk. From a practical standpoint you would do both.

Here is a simple analogy. A tiny little car doesn't consume any less fuel than a big SUV if you don't drive anywhere..... LOL!

A fuel pump system can't save you a lot of money if your home doesn't need as much heating or cooling because the insulation was beefed up at the same time.

But you don't care about savings. You care about how much it costs you.
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savings is not a good metric

with anything that is a necessity, we should always look at the total cost of ownership as a primary factor driving decision making.

with homes we intend to live in long term other primary factors should be overall comfort, health and safety issues as well as the overall cost of ownership.

the few people who do practice in my field, and I exclude 99% of those "energy advisors" cranked out by the gov.

the house is a system and most be examined as a system. Improvements must be made to the whole looking at how each change will impact the system, its health, durability, comfortability, energy efficiency... etc etc.

unlike a car, it is very hard NOT to drive your home, and north americans have historically adamantly refused to sit in the cold and dark. They demand lights ablaze with sauna like conditions
 
I did not use insulation in my example above, since it is not the number one component of heat loss, but it would be upgraded as part of air infiltration mitigation.

Insulation upgrades can and are mostly done without improving air infiltration rates, which makes the impact of upgrading insulation alone less effective but "perhaps" still better than HVAC upgrades when it comes to lowering energy costs.

Why perhaps? Lets say that same house (which had R24 attic insulation) had the attic insulation upgraded by adding a further R24 of blown in cellulose. The owners would not likely see any reduction in the energy costs because the heat loss attributed to the attic space is such a tiny percentage of the overall heat loss. Homeowners do that work though because they're told it will save them money and because they got an incentive. The government pays millions to record a greenhouse gas reduction because they care about the aggregation of savings.

BUT a piecemeal approach is foolhardy.
 
This is an extreme case, I realize, but 20 years ago this month, I lifted my first house and built a basement underneath. It was on posts with gaps around the skirting, no floor insulation, and was shifting around. When I started, my monthly heating costs were over 600/month.

I built a 8" block foundation, set in 1.5" with 1.5" R7.5 exterior XPS from the footings up to the joists. Then i wrapped the rest of the house with 1" r5 xps lapped down over the 1.5" foundation insulation, sealed. I aslo installed new windows and doors, and a new high efficiency gas furnace. I studded the basement and added R13, and sealed the rim joist areas. I paid attention to air sealing as much as possible. My monthly gas bills went down to usually less than 100, to a worst of 120 one January. My annual heating costs were less than my monthly costs before.
 
TorontoBuilder said:
savings is not a good metric

with anything that is a necessity, we should always look at the total cost of ownership as a primary factor driving decision making.
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Yes, you will see I ended with that very statement.


TorontoBuilder said:
unlike a car, it is very hard NOT to drive your home, and north americans have historically adamantly refused to sit in the cold and dark. They demand lights ablaze with sauna like conditions
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It was not intended as a comparison. Only as a way of showing that efficiency alone is not a good metric. Again you can see that in my last statement. This fully supports your total cost of ownership assessment comparison.

Fundamentally, we do not disagree. Just trying to help by adding another perspective.
 
Susquatch said:
Yes, you will see I ended with that very statement.




It was not intended as a comparison. Only as a way of showing that efficiency alone is not a good metric. Again you can see that in my last statement. This fully supports your total cost of ownership assessment comparison.

Fundamentally, we do not disagree. Just trying to help by adding another perspective.
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I was reinforcing your points rather than arguing that you were off base...
 
Can a blower door test help to pinpoint areas of air infiltration?

Our house has several exhaust fans and a fresh-air intake for the furnace, it will soon have a HRV. Wouldn’t a blower door test just suck air in through these and not tell you anything about where air is leaking in elsewhere?
I guess I could use smoke from an incense stick to see if anywhere else was letting air in?
 
StevSmar said:
Can a blower door test help to pinpoint areas of air infiltration?

Our house has several exhaust fans and a fresh-air intake for the furnace, it will soon have a HRV. Wouldn’t a blower door test just suck air in through these and not tell you anything about where air is leaking in elsewhere?
I guess I could use smoke from an incense stick to see if anywhere else was letting air in?
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There are several types of blower door tests used to measure the airtightness of a building or home. One of the main tests for energy efficiency programs is the "as operated" blower door test, which measures a building's airtightness under normal operating conditions during winter months. This test is designed primarily to quantify the amount of air infiltration during normal operating conditions, rather than thoroughly examine the building envelope to identify problematic thermal bypasses. The operator however often helps the homeowner identify air infiltration points using a smoke pencil for minor draft proofing efforts. However, there are issues with the way this test is often marketed to consumers as being able to make a meaningful impact on energy efficiency given the usual method of conducting the test as part of a brief energy efficiency audit.

Another type of blower door test is performed during new home construction or major renovations by private inspectors and specialized insulation contractors. This test involves sealing all intentional openings in the building envelope to accentuate leakage from unintentional thermal bypasses. Thermal imaging cameras are often used to locate these bypasses, as well as other tools and techniques.

Sometimes, when thermal cameras cannot be used, foggers are placed inside the building, and the blower door test is done in reverse. However, this method can make it harder to locate and repair the actual source of the thermal bypass.

During a blower door test, a target air leakage rate is typically set, and an air sealing crew is present to fix any deficiencies as they are found. This can be a lengthy and skill-intensive process, which may require specialized contractors.

Regarding fresh air inlets for furnaces, high-efficiency furnaces have their own sealed combustion inlet, and there is no need for a separate combustion air inlet. Therefore, older furnaces should be replaced, and any combustion air inlets should be eliminated.

In summary, if you are seeking a blower door test to identify issues, it is important to find a specialized contractor who performs blower door assisted air sealing and provides target air changes per hour before the test. This service may be expensive, but it is an effective way to improve energy efficiency and reduce costs in the long term.
 
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