We think of our homes through the prism of which discipline- electrical, insulation, plumbing, HVAC issues, siding issues, roofing issues… we are addressing issues in our homes. We seldom think of these as interconnected parts of a system like what we might think of a tree with leaves and roots and bark- all parts interactaing to create a vibrant and healthy tree. Houses are not alive, but the different parts do impact each other. and herein lies the problem.
The home as a system idea impacts our homes in two critical ways.
- The impact of single-minded acts by contractors can damage the configuration of other key components, but also
- each of these disciplines impact the overall home performance– how well the home heats and cools and how comfortable the home is….
lets see if we can explain these two concepts better.
The vast majority of contractors see the world through their own expertise, their own toolbox. Most of them are blind to their impact on any other component in your home. More than one cable contractor has drilled a hole in the wall for access and left that home with a water entry point- an air leakage point. Many of these have turned into problems.
More than one contractor has added a new electrical service panel or circuit switch and paid little attention to the insulation layers being properly refitted, or the hole created- sealed back up.
You can hire a remodeler that is focused on getting things done, and looking good but not really paying attention to connecting the new addition to the air barrier of the rest of the house, or considering how well they fit into the insulation layer, and the HVAC system and the tie-in to the weather shell which keeps the leaks out. Work is often good enough to get by, with no consideration for the home as a system. We discuss remodeling as a subject here. -LINK-
They are not thinking about the overall purpose of maintaining a solid well built home and that they are part of a continuing effort to maintain the home as a working and effective system…
- watertight weather shell that sheds water effectively to keep leaks out
- maintain an air barrier envelope around the entire house to keep the conditioned air separated from the great outdoors.
- keep and protect an insulation layer to sepapate the conditioned space from the outer space. hee hee, I am testing whether you are paying attention.
- protect and maintain the effectiveness of the HVAC system so that it distributes air effectively
The thinking of the home as a system moves beyond not just poorly impacting the house components during modification but understanding that all the components of the home interact with each other in according to natural systems.
This might be a bit confusing, so lets look at some examples again.
Traditionally, the HVAC service contractor saw all comfort issues related to big pieces of equipment. Cold spots? bigger furnace section in the air handler. Humid? add a dehumidifier. Not humid enough, add a humidifier.
Times have changed. HVAC is becoming aware of the concept of home performance which fits in well with the concept of the home as a system… and becoming aware of the natural forces which are at work in homes that must be accounted for, to give homeowners comfortable and healthy homes.
Things are not perfect. Many professionals are not on board here. Remodeling is changing quickly also, but there is always a wide spectrum of quality in remodeling. What you get is left up to you, and you need to have your systems in place to make sure you hire the right people- that is- after you understand how all these issues fit and are critical to having a healthy home, keeping moisture out and having an effective HVAC system which distributes conditioned aire effectively through your home.
But building science- actually gathering,actually testing, and actually analyzing data is helping us better understand how each component of the house and its function fits in the proper operation of your hime, impacts the performance of the other components. We all need to see our homes as a system.
Moisture issues need to be addressed at the level of root cause. Thinking about your home as a system of interrelated parts that impact each other helps us understand that air leakage is a key factor in moisture issues- but maybe you also have a contributing problem with bathroom fans- kitchen fans or maybe your duct system has some deficiencies. You need root causes and you need to see and understand the impact of all other home components and their roles in root causes.
Everywhere you turn someone or something is trying to sell you a “Green” products. Do they work? Do they work within the context of your home? What actually makes sense for you? What actually makes a good investment in saving energy and money? The value of any one thing you do to your home must be evaluated within the context of your home being a system. Only from a systems approach can you gain the perspective of what can make a difference for you and what is just expensive trivia. We explore what not to buy here.
Improvements to your home can change the system dynamics too
We want much tighter homes. Air leaks cause all kinds of issues. But tighter homes, make it much more critical to understand where you are getting your indoor air. It usually leaks in from everywhere, but the tighter your home gets, the fewer natural air exchanges you are getting.
This increases the possible issues with combustion appliances and make up air. Combustion appliances working with fans operating can conceivably create negative pressure which can hinder the evacuation of combustion products up chimneys. Exposure to combustion byproducts like carbon monoxide can make you chronically sick or even kill. Do you have combustion appliances anywhere in your home? These issues have to be understood and integrated into the use of the home. This a perfect example of needing to se the home as a system of interrelated parts.
As soon as you start dealing with air leaks, and improving insulation, you are impacting the size of the HVAC unit that you need in your home. The heating and cooling loads go down and you need smaller equipment, or equipment that is able to adjust to a varying load to maintain efficiency and proper humidity in the home. HVAC units that are too big are a serious problem. Now this is a byproduct of people thinking bigger is better, and too many HVAC companies not caring or are unwilling to disabuse people of this myth, but here is another clear example of where changes in the home need to be adjusted for as other components change.
We have already discussed the traditional tendency of HVAC contractors to add bigger equipment or dehumidifiers or humidifiers as plug-in solutions to deal with issues of too hot or too cold or comfort issues. Bigger furnace section, more tons of cooling have been the answer to comfort problems. But without attention to all the parts of the system in play- air leakage issues or ducting issues- insulation and solar gain issues- you can spend money on the central unit and not only get little relief for your discomfort, but acquire new problems associated with the oversized unit.
Investing in insulation is a perfect example.
For decades a pink critter that thinks he is a panther has been touting fiberglass insulation. Add more- save energy- save money. Contractors only peripherally associated with insulation- HVAC companies, roofing companies offer you special deals to top up that insulation while they are on the premises.
Adding insulation requires a systems approach. Do not top off that insulation until you address certain other critical factors as well.
Unless you address air infiltration issues- and insulation issues as you evaluate the performance of your HVAC system, well you are failing to see you home as a system.
What is the bottom line here?
It rests on you, the homeowner, to make sure the people you talk to- the contractors you hire, the consultants you converse with, understand that all homes are systems and take responsibility for reconnecting, refinishing, to properly matching up to existing structure and mechanical systems in your house. you must make sure everyone you hire is thinking of your home as a system. We work hard on this site to give you the information you need, to point you towards the types of contractors who will help solve your problems and not move you sideways into a further problem.
We must understand the concept of our homes as systems and we need to make sure that our contractors we hire understand that also.
The challenges you evaluate, the solutions you look at and the investments you make in your home need to be evaluated from this systems approach.
Any thoughts? any comments? Feel free to add to the conversation below?