The Official HVAC 101 Post: The Do’s And Don’ts Of Heating, Cooling, And Water

In my attempt to learn the ins and outs of the entire renovation process (and pass it on to you), I recently did a deep dive into how we can get the most energy-efficient HVAC and water heating system. Learning all the new technology was a beast. It hurt my brain, and I was frankly pretty frustrated with myself for not easily grasping exactly how heat pumps can work for both the heat/AC and water. (Turns out there are two different types of heat pumps – we’ll break it down below).

Gas furnaces are easy to understand, and electric heaters, I get. But these heat pumps are a little more complex. Their genius lies in being SUPER efficient and if you are renovating right now, you REALLY need to keep reading. I wish I had known all of this when we renovated the Mountain House, so this time around I’m doing it RIGHT. To better understand Heat Pump technology, we had meetings and calls with Rheem experts and Electrify Now (an energy-efficient nonprofit in PDX) as well as with our local contractors. I took all the notes and even recorded the meetings in hopes of distilling them down for you in a way that would help us all become experts. And y’all, I FINALLY GET IT. So today, for those of you who are renovating or really just like to learn about HVAC and water heating, I’m breaking down all the dos and don’ts that I learned.

DO: Choose Electric (Like A Heat Pump) Over Traditional Gas. Here’s Why:

Well, as homeowners who have the privilege to renovate, Heat Pumps are simply a better way for our earth, our home, and our wallets.

1. We are trying to reduce our dependence on natural gas as a fossil fuel energy resource and we live in Oregon, which is quickly changing its energy reliance over to green energy — solar and wind. Because we want to reduce our carbon footprint, this is a good switch to make while renovating.

2. Rheem heat pumps will save you money long term by reducing your energy bill. They are just much more energy efficient because they use heat energy from the air (which I’ll explain below).

3. Simply put, the variable-speed heat pump system and Hybrid electric heat pump water heater I selected (which I go into later) will give you a better, more comfortable home. So for those of you wary about anything too new/green, or if you just don’t want to spend the extra bit up front, understand this: Heat Pumps will not only save you money long term but you’ll like being in your house more. A Variable-speed heat pump will efficiently adapt to your air needs and help lower humidity while Hybrid Electric Heat Pump water heaters cool and dehumidify the surrounding air without producing nitrous oxide and carbon monoxide emissions. Pretty awesome.

Natural gas is inexpensive, I know, and I’m not saying that if you have a perfectly good gas furnace or water heater you should scrap it (because that is so wasteful in itself), but IF you are installing a new system, seriously think about getting the better, newer, more energy-efficient product. It’s like the range debate — don’t throw away your old gas range, but if you are getting a new one, think about induction.

DO: Opt for Rheem’s Products And Their Smart/Advanced Technology

Yes, this is a sponsored post, but I sought them out and pitched to THEM after researching, asking around, and consistently being told that Rheem’s heat pumps, smart technology, and products are the best in the business.

1. They’ve been making these heat pumps for years, and they have a solid product that isn’t new to the market. Moving forward, this will be the product builders will use because of the high efficiency and smart technology.

2. With regards to heating and cooling, Rheem’s system recommendation is way more accurate because they use a software called Design Star (lol), which bases the heat load off windows, layout, and humidity. Most basic HVAC contractors just do a basic square foot calculation (every 500 square feet requires 12,000 BTUs).

3. Rheem’s more thoughtful system recommendation process means that no energy is wasted and that the home will be comfortable for years to come. I was EXTREMELY excited about this.
4. One of the biggest selling points for us was the EcoNet® app — you can manage your HVAC and water heating in one place. Plus it can flag leaks, check system health, remind you of maintenance, and WAY more. Other companies don’t have a complete air and water solution, so we were excited that a brand could be a one-stop solution for all the nitty-gritty details.

…Wait, So What Exactly Is An “Electric Heat Pump”?

Here’s the best way I can simplify it for an average homeowner like me: It’s an advanced way to heat and cool both air and water by using the heat energy from the surrounding air and reduced electricity. Heat pumps have been around for decades and are far more energy efficient than other air and water solutions. Heat pump installations are quickly becoming the norm and are even a requirement in new builds in many states. If you want to get into the really nitty-gritty stuff, this is how the process was described to me verbatim: 

Essentially, to heat water, the heat pump water heater’s fan pulls in air over its evaporator coils. Because the refrigerant in the evaporator coils absorbs the heat energy from the air, the exhausted air is cool. Then the super-heated refrigerant transfers heat to the water in the tank and returns cool refrigerant back to the evaporator. This all just keeps repeating. To heat and cool air, the heat pump transfers heat from one space to another (similar to the water heater). For example, in the summer a fan pulls indoor air over indoor evaporator coils. The refrigerant in the evaporator coils absorbs heat energy from the indoor air and exhausts cool air. Then the super-heated refrigerant moves to the outdoor coils where heat transfers to the air. Then the cool refrigerant returns to the indoor evaporator where the cycle repeats. I tried to get my mind to understand the science, then realized that I don’t really need to. It’s a better, more advanced, and efficient product, with a ton of advantages, full stop.

Let’s First Talk AC And Heating

DO: Consider a Variable-Speed Heat Pump System for Your HVAC — Keep Reading!!

• Traditional standard “single-speed” furnace and HVAC systems can be wasteful, as they are either ON or OFF — they may produce more heat or AC than you need and use way too much energy, plus you aren’t getting precision comfort. A variable-speed system is smarter and more nuanced, fluctuating based on your home’s needs all the time, to the point that you barely notice it’s there because you are simply very comfortable.
• A Variable-Speed Heat Pump is like how driving on the freeway is so much more fuel efficient than driving in a city — it’s the starting and stopping, the perpetual ON and OFF of it that wastes so much gas (or in this case, electricity). Once I heard this, I finally understood! A variable-speed heat pump system self-maintains instead of overcorrecting.
• Here’s how it works: Rheem’s variable-speed systems are flexible — a little bit of heat will come out if you need a little, and a lot of heat will come out if your house is super cold. Not only does it adjust the temperature on its own, but it also adjusts the amount of airflow — it adjusts to 1/4 of a degree, so your house is the perfect temperature for you, ALL the time.

Rheem systems maintain your desired temperature with as little waste as possible. This tech is getting more and more affordable, because of scientific improvements, but also because of regulation. It’s great to see this proliferate because it’ll mean that it’s an accessible choice for everyone. 🙂 Many states will be moving to require all new construction to have electric heat pumps — it’s like electric cars. It’s coming FAST to mass market, and Rheem has been doing it for years.

DO: Find An HVAC Contractor Who Is Versed In Heat Pumps And Cares About Energy Efficiency

Not every HVAC contractor will suggest this newer technology, because not everyone is educated in it. YET. So make sure that whoever you or your GC is hiring knows how to do this. (Rheem has a “Find a Pro” database to help you.) Many still want to recommend gas furnaces, because that’s what they have installed for decades, and sometimes it is the right choice. Here are some things to think about when hiring:

1. Ask for a “load calculation.” If they just do it based on square footage, it likely isn’t as advanced or as good as you want (especially for a home over 1,500 square feet). Ask to see previous load-calculation work, as this is a good indicator that they are the kind of person who thinks the way you want your HVAC contractor to think.

2. For big projects like ours, look for a contractor who presents multiple options…“a good, better, best” type of scenario, which directly correlates with your budget. If they only offer one, they should be able to thoroughly articulate why they are recommending it over others.

3. Another critical thing to look for is a contractor who is recommending a “zone solution,” and if they are not, ask them to explain how it is going to evenly heat and cool your space throughout the year.

During our research, we came across Rheem and GreenSavers, our HVAC contractor. I had multiple calls with a few energy-efficiency experts in Portland, and they all recommended this company (Hi, Craig! :))

DO: Have Your HVAC System “Zoned”

For those of you ready to nerd out on our HVAC zones, we got you. I actually feel so empowered to know all of this now.

Zones, zones, zones…this is one of the most critical ways to optimize efficiency and comfort. For example, if you have a two-story home with bedrooms on the second floor, you need that space comfortable primarily at night, for sleeping, but not so much during the day. With a zoned system, you can program each zone separately based on how you use the space throughout a 24-hour period. It makes so much sense because you won’t be overheating or cooling rooms when they aren’t being used.

Craig with GreenSavers looked at the layout and unique characteristics of the space and decided four zones would work best for the farmhouse. Each zone has its own thermostat, so they can all be controlled independently of one another for maximum comfort and efficiency, an all-around WIN!

Zone 1: The main living area, including the kitchen, living room, and family room

Zone 2: Upstairs

Zone 3: Primary suite and mudroom

Zone 4: Sunroom

Zones 1 and 2 work off of the same electric heat pump compressor on the side of the house. The electric furnace is in the basement and feeds to the ducts that run under the main floor and up the chimney chase to the second floor. Since the ducts are connected, dampers have been installed so the upstairs and the downstairs can be set to different temperatures throughout the day… AMAZING. Our primary suite and the mudroom are the third zone, controlled by a mini-split installed in the new basement. Since the ducting doesn’t extend long distances, it helps minimize the loss of heat and cooling, making it more efficient…YAY. The sunroom is an addition with A LOT of windows, plus it’s set down from the great room, so Craig from GreenSavers thought we should treat it like its own microclimate, which it will have. On hot, sunny days (yes, we do sometimes have those in Portland) with all the exposure from the skylights and windows, it will likely be hotter than the great room, and in the winter it will be cooler, which is why I will love those radiant-heat floors warming my tootsies while I type away. There is a second mini-split and ducting for the sunroom in the crawl space under the room, and both mini-splits run off of the heat pump compressor on the back of the house. Now a lot of folks hear mini-split and immediately think of the boxes mounted to walls (which they often are), but because we created this plan from scratch, GreenSavers was able to design the system so the mini-splits are BEHIND the walls, not ON the walls…brilliant! Now you might ask, why not do mini-splits for the whole house? They are a fantastic option, though it doesn’t make sense for a space as large as the whole house. But for a situation like this, it is brilliant!

DON’T: Get Your Duct, BTU, And Unit Sizing Wrong

Obviously, rely on your local expert/contractor, but I always feel empowered when I know what I’m talking about. 🙂

• So you’re going variable speed — you gotta make sure the sizing is done properly. If it’s too big or too small, you’re going to have problems. You want your BTUs to line up with your needs, neither too high (wasteful) nor too low (inefficient).
• With too big of a unit, dehumidification won’t happen — it’ll put too much cool air into the system and then turn off. With too small of a unit, well, your home just won’t be too comfortable everywhere. 🙂
• A properly installed system provides a comfy AND healthy environment — we’re shooting for 40% to 60% indoor humidity. This helps prevent allergies, asthma, dust mites, static, and floor warping. Our variable-speed system is designed to maintain the level of humidity, which will protect us AND our investment. 🙂
• Get your ducts in a row (sorry) — size and location of ducting are also super important. Now your HVAC contractor should know this, but after our calls about it, I learned this is one of the most common problems. Y’all, get a good contractor who knows their stuff.

DON’T: Get A Dated System — New Smart Tech Is Here

While we only renovated a few years ago, up at the mountain house our contractor wasn’t versed or interested in energy efficiency, and we now have a dated system. The smart technology is awesome and has been around for years, so you aren’t getting the first version. As I wrote above, Rheem has the EcoNet Thermostat, which can be controlled from an app, and it has all of your HVAC and water information together. You can see your usage, your temperature, has easy voice control, and you get important equipment alerts that are sent directly to your phone or email.

Oh, and you even have remote access via the EcoNet App and on top of all that, the scheduling is simple with one-touch energy savings. “One-touch energy savings” means that you can save energy by adjusting your thermostat with one touch on the screen. This also means you can schedule your temperature settings ahead of time – for example: 74 during the day. 69 at night. Love how easy and efficient it is.

DO: Be Thoughtful About Vent Placement (+ Make Sure There’s Enough)

• Do evenly space the vents throughout a room and house. This is common sense, but can be easily overlooked.
• Do place vents under windows — you’ll be blanketing the heat loss/gain with warm or cool air, and it’ll circulate through the room better.
• Don’t put a vent or return under where you think potential furniture will be. We put one big return under our kitchen island because it has legs and everyone agreed it was fine. But essentially, walk your house and imagine where furniture and rugs will be, then try really hard to avoid putting any vents or returns under them.
• Do make sure that if you are replacing your flooring, you order wood vents to match, so you can install them to be flush. I’ve made this mistake three times now (not on this house!) and had to put in aftermarket vents, which is fine, but less pretty.
• Do put your returns where you’ll be able to easily change the filter (should that be your system). At the mountain house, one of ours is 16′ off the floor (in the loft) and requires a terrifying ladder scenario.
• Do place your thermostat in the middle of a room (they can’t be hidden in a closet, as much as we all want them to be).

While we haven’t lived here yet, we are going to do a follow-up post to show you how it works six months in. I just feel so grateful and taken care of, knowing that we have an excellent system and product that can meet our needs year-round and for a LONG, LONG TIME. Lastly…

DO: Mix and Match If It Meets Your Needs

It may not be tenable for you to go all-in on electric right now, but you can still mix and match. Rheem also offers gas furnaces, which may make sense for you depending on kW rates, gas rates, etc. We went all-electric because we’re trying to reduce gas dependency in this house, but if you live in a climate where you’d feel more comfortable having a gas backup for emergencies, you can still work with Rheem to find a solution that works for you.

Now Some Info About Heat Pumps And Water

DO: Consider Going With A Hybrid Electric Heat Pump for Water, Too

This is the same thinking as the HVAC — to reduce electricity or gas consumption and to be more energy efficient. With a standard gas water heater, you’re getting about 50 cents of heat for every $1 you spend on gas. Standard electric water heaters are more energy efficient than gas water heaters – usually, you’re getting between 90 and 98 cents of hot water for every $1 you put in. (As an added bonus, you don’t have to worry about carbon monoxide or venting exhaust out of the house when you’re dealing with an electric water heater.)  

Then, you have hybrid electric heat pumps – that’s what we’re getting – which are the most energy-efficient water heaters on the market. (And like the standard electric water heater, there’s no need for venting out combustion gasses.) We ended up opting for two 80-gallon hybrid electric heat pumps, which are INCREDIBLY efficient – we’ll be getting about $4 of hot water for every $1 we’re spending on electricity. Consult with your local plumbing contractor to find the optimal heat pump water heater for your household.

As an added bonus, this hybrid electric heat pump model can effectively act as a small air conditioner. A lot of people in hotter, more southern climates will install these in the garage, which will cool down the space – it basically sucks out the hot air, uses that air to heat your water, and blows out cool air. (Again – these heat pumps are kind of like an AC in reverse.) The two hybrid models we chose will save us nearly $1,000 per year combined in water-heating costs (compared to two 80-gallon standard electric water heaters), and lots of states offer BIG additional rebates to accelerate the adoption of these more high-tech solutions. We believe these will pay for themselves in less than two years, which is amazing.

Final Thoughts

DO: Save Money Long-Term

I really wanted some hard data on how much a hybrid electric heat pump water heater and variable-speed heat pump system cost and how much it will save you, so we did some digging. (Keep in mind costs and rebates are super dependent on your region, your contractor, and your usage, but this may be a helpful baseline.) 

For Water: Although the Hybrid Electric Heat Pump Water Heater we opted for costs more upfront, homeowners may save up to $315 per year on 40 and 50-gallon models or up to $491 per year on the 80-gallon water heater. With rebates available up to $1,000 and an average HPWH (that stands for “Heat Pump Water Heater, btw) rebate of $500, the hybrid electric heat pump water heater pays for itself in 2 years or less.

For Air: This is awesome. The Variable Speed Heat Pump provides cooling efficiencies up to 54% higher and heating efficiencies up to 58% higher than typical heat pump designs. On top of that, you can expect to save more than $7k in lifetime savings (based on DOE calculation for estimated national operating costs for a 3-ton 10 SEER vs 20 SEER, 6.8 HSPF vs 13 HSPF, and a 15-year life expectancy). I know that last part is a lot of info you might not understand yet but here’s more info to help! Also for even more help with saving money, you can check out their rebate center for both air and water:)

We are so excited and feel so empowered (ha) knowing more about the ins and outs of HVAC, water heating and energy savings. Again, a lot of this might be specific to your house (you’ll need to be sized by a local contractor to fit your air and water needs) but if you are nervous about getting a heat pump because you haven’t had one before, you’ll come to find it’s the most energy-efficient option on the market.

Thanks to Rheem for sponsoring, as well as Electrify Now, GreenSavers, and Northwest Natural for helping make this house as energy efficient and yet comfortable as possible.

*Photos by Kaitlin Green

The post The Official HVAC 101 Post: The Do’s And Don’ts Of Heating, Cooling, And Water appeared first on Emily Henderson.

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