Heat pump

In a previous post I reported on a green building forum presented by the Sunshine Coast Regional District.

I didn’t tell you one of the most important things I learned from Murray Frank, the speaker from Constructive Home Solutions.

He told a story of his British father-in-law, whose lifelong habit was to turn down the heat every night, to save energy. After his home heating system was updated to an air-to-air heat exchanger (or heat pump), he continued to turn down the heat each night before going to bed. His son-in-law advised him not to turn it down, but he continued to do so, while steadfastly denying that he was. When s-i-l saw him turning it down, he devised a plan. He installed a fake thermostat in place of the thermostat f-i-l adjusted each night. Then, he installed the functioning thermostat in a hidden location, set it to f-i-l’s daytime temperature. F-i-l continued to turn down the fake, but reported to s-i-l that the system was finally fixed, because his heating bills were considerably lower!

What gives?

Well, the heat pump works on the differential between the air inside and the air outside. If the thermostat needs to jump 2 or 3 degrees suddenly in the morning the (necessary) back up heating system (a furnace) jumps in to get it to the higher temperature quickly.

The furnace - back up heating system

Last winter, I observed the “auxiliary heat on” notation on the thermostat every morning, and was frustrated because the outside temperature wasn’t very cold. Wasn’t our heat pump working as promised?

Now that we’re not turning down the thermostat every night, the heat pump doesn’t have to raise the inside temperature suddenly, and our heating bills have gone down. (An aside: Since last winter, we have installed a simple electric heater with a blower fan in the studio, so there are additional electrical demands, too. Our heating bills should be higher, not lower.)

So, I conclude that turning down the heat at night doesn’t save energy. Take that to the bank.

At least, if you have a heat pump!

Recently I attended a Green Builders Forum offered by the Sunshine Coast Regional District for  builders, developers, realtors or anyone contemplating building a new home as a ‘homeowner builder’. It provided an opportunity to:
1.       Discuss 2012 Building Code changes – a significant shift in building requirements across the province
2.       See a hands-on demonstration of air leakage testing
3.       Review important new building techniques to save time and money
4.       Learn about new guidelines for EnerGuide and Energy Star

Murray Frank, from Constructive Home Solutions for the Homeowner Protection Office, gave a fast-paced and most informative rundown of the new Energuide requirements. The salient point he made was that, to raise the Energuide rating to the soon-to-be-required 80+ level for new homes, it will cost the builder an average of only $8000 more than it currently costs. This estimate was based on sample homes constructed in (if I remember correctly) Edmonton, Kelowna and Vancouver, and it can vary depending on labour costs.

Since it has cost us considerably more to build green (I estimate at least $60,000), I was skeptical about this claim, until he explained that it’s just the airtight, well-insulated building envelope (including non-thermal-bridging structure and windows and doors) that can bring the home to 80+. These are the essentials the builder invests in at the outset, steps that would be difficult and expensive to remediate after the house is built. Other energy-saving strategies, such as energy-star appliances, heat recovery ventilation, air source heat pump and solar or on-demand hot water for example, can be added on in later years to improve the rating even more.

I also learned that Fortis, BC Hydro, Federal and Provincial governments, and the regional district are providing incentives for building to this Energuide level now. Up to $2200 in rebates from BC Hydro, a deduction from the cost of a building permit, and, as before, considerable grants to retrofit existing homes. Some examples: furnace replacement – up to $1290; air source heat pump- up to $2790; tankless hot water heater – up to $675; Energy Star windows and doors – up to $100 ea ($3500 worth in our house); insulation in attic, exterior walls, basement and crawlspace – up to $4425; heat recovery ventilator – up to $1175; energy star appliances – up to $200. I listed those particular examples because that’s what we have included in our home. However, we do not qualify for ANY of those incentives – up to $16855(!) because we have already built, and this applies to new building permits (or existing home retrofits.) Once again, our project falls between the cracks. Do I sound bitter? We did get a provincial government rebate to the tune of $200 for our energy-star-rated dishwasher and clothes-washer.

I guess I just have to remind myself why we wanted to build green in the first place, and be happy that many others are being “incentivized.” But it’s kind-of hard to take.

We’re not anywhere near close to “off the grid” with our project, but you may be interested in reading an entertaining blog from Dave, who is living off the grid on an island on BC’s coast. This particular post is about alternative energy sources.

Way back at post #24 I explained the rationale behind our choice of the greenest-option-in-our-circumstances heating system. Well, after many delays and excuses, the heating system is finally functional. And, my goodness, it heats the house up very quickly (minutes!)

Here are some photos of the system:

This is the 15 seer heat exchanger that resides outside the house.

Our heating guy calls this an "air handler". It's the same as a furnace. Very elaborate ductwork, and seems like overkill, but it's meant to start up when outside temperatures go below -10, because that's when the heat pump can no longer exchange the cold into heat (I think!)

As its name describes, this is the unit that delivers the heat recovery ventilation. It takes the heat and moisture out of the air, and returns the heat to the air handler to recycle. The vents are placed up high in all bathrooms and the kitchen, where warm, moist air collects. This unit and the furnace are in the crawl space.

Although electric under-floor heat in the bathrooms uses a fair bit of energy (9 watts per heated square foot), it is a little luxury that we can choose to use or not to warm our feet in the cool of our winters.

We bought the Flextherm heating system kit, which includes the appropriate length of green-covered heating cable for the size of the room, as well as round guides for the wire. The thermostat is purchased separately. I chose to donate the guides to the Habitat For Humanity Restore (whence cometh many of our building materials).

The Flexsnap system

Instead, I purchased the Flexsnap 12″ gridded squares to clip the wire into. It is easier, will raise the level of the tile equal to the 3/4″ fir flooring that meets it at the doorway, and at $2 each, for a small room, I thought I could justify the expense. Another advantage is that they stabilize the floor so that a second layer of plywood is not necessary before tiling. Some internet research suggested that one could just hot-glue the wires in place, forget about the guides or gridded squares. I’m very glad I didn’t try cheaping out on that step. It would have been constricting, and I would fret over whether I was damaging the wires.

The orange Flexsnap blocks are quick to install directly onto the plywood sub-floor with screws.

The heating cable clips into the tiles, 3 or 4 inches apart. It starts near the thermostat.

After installing, the wire needs to be checked with an ohmmeter (or multimeter) to make sure it is conducting electricity/verifying the resistance/not broken.

I’ve spent far too many hours cutting the white 1″ square tiles out of the all-white 12″ blocks of tiles and replacing them with brown ones. 88 x 25 = 2200!

The "renovated" bathroom tiles.

I hot-glued them into place, but found when it came time to install them, many of the brown tiles fell out of the blocks. Just made more work. I learned that only good-quality large glue sticks work, not the little craft sticks.

All the voids in the Flexsnap tiles have to be filled with the flat part of the trowel before the notched trowel is used to raise the mortar to accept the ceramic tiles. The 88 square feet of floor used up four 50-lb bags of polymer-modified mortar.

Raff came to help, mixing the polymer-modified mortar in the wheelbarrow for me, so I could steadily apply the tiles on top of the Flextherm  heating wires. This made the job go much more smoothly.

The bathroom floor

Insulation is arguably the most important energy-saving component of our green home. We experience strong winds here almost constantly, and have incorporated several heating systems, as it turns out. In theory, we would only need to use the centrally-located thermal mass fireplace for heat, as long as the house is well-insulated.

The idea of R-Value as a measurement of insulative ability of an insulation is quite misleading. We might choose to use R40 fibreglass batt in our ceilings, but because it is impossible to prevent spaces or compression of batts once they are installed, wind and air can make their way into the heated space in hundreds of places.

The soy-based, closed-cell, 2-pound spray foam insulation fills every possible space to prevent air leaks. 3.5″ of foam is rated R28. Effectively, it is much better as an insulator than R40 batt. It costs about 4 times as much as regular batt insulation (average of $5/sq. ft. in our case) but the cost will be recovered in a short time in energy savings. (I will do more research and provide specifics and a few links later.)

Action Spray Foam came over from Surrey to spray our house. The compound they use is heated iso-cyanate, which is nasty stuff in its liquid form. It smells like the inside of a dirty rubber hose times ten. The sprayers use full gas filter masks and risk burns and hair removal on areas not covered by protective clothing. The rest of us work outside or in the RV.

Spraying produces lots of inert waste pellets (labelled “popcorn”). Currently, Action takes them to the landfill.

The foam that spills over the stud edges needs to be cut away with saws or scrapers so that drywall can be applied without bulging.

spray foam in the crawl space

insulation in the basement bedroom

(….pause while I chase a mouse)

One of my tasks when I arrived back on site, after vacuuming out all the wall cavities, was documenting the “house guts” before they get covered up by insulation and drywall. Alice arrived on her bike to help (well, she arrived to observe the studio concrete-forming process, but as Raff so astutely observed, visitors are quickly pressed into service.)

Basement hallway

The process involves laying two tape measures along the walls at right angles to show where all the wiring/plumbing/heating elements are located before we cover them up with insulation and drywall.

insulation in basement hallway

This is one-fifth of the old wooden garage door I got on Craigslist for $90. It’s pretty ugly, but I think I can turn it into a silk purse.

That's not smoke above the door - we just haven't cleaned it yet.

And the ugly smoking door is no more. We have a silk purse of a functioning fire. D put gaskets along the top of the door, in spite of Lakeshore Design’s advice to the contrary. We also got a draft going in the side chimney with a burning newspaper before lighting. We didn’t remove the chimney cap. It’s a miracle!

The progress on the house is not all that apparent this week. It’s not showy. Rather, it’s the systems we’re working on, which will all be concealed behind drywall and other finishes.

red and white water

The plumbing: No, it’s not just Canadian flag-waving here. The water pipes need to show that there are two completely different systems: the red for the collected rainwater to flush toilets, and the white for potable water to the rest of the house.

Neil adds another duct to the montage

The heating and Heat Recovery Ventilation (HRV): It’s a complex system, with the attic ductwork needing insulation, and great and small ducting pipes trying to hide in closets, walls, ceilings, floor joists, crawl space. The crew has been working for 3 weeks on this. The irony: it’s supposed to be a back-up heating system (heat pump and air handler). The goal is to have the thermal mass fireplace (TMF) provide the majority of heat in the cold weather.

smoke gets out where it's not wanted

(At this point, the aforementioned TMF is a dirty word in our house. On our first small firing, it smoked mightily, from around the door. I’m quite sure it’s been installed according to all the instructions, but clearly the air inflow or outflow is not functioning the way it should. In theory, the smoke exits at the bottom of the unit, through an 8” masonry chimney pipe from the side of the burning chamber. Kerry, the fellow who sold the kit to us (Lakeshore Design in Ontario) assures us that we don’t need any braid gasket around the door, and that it’s “easy” to straighten out the door. He’s not a very good listener, nor does he know how to provide good customer service. He just repeats the info in the installation guide and talks over us. He says we need to take off the chimney cap that our stonemason took half a day to install. I don’t believe the chimney cap is restricting any airflow at all.)

the "offending"? chimney cap

Electricity: John and helpers have also been here for nearly 3 weeks. The various systems are rather interdependent, needing wiring for the fan or hot water heater, or space around plumbing pipes for the ductwork, for example. John estimates 4000 feet of wire. We’re trying to think ahead to end use and comfort. Lots of lighting for older eyes, plugs on the living room floor for table lamps, pot lights where we might need them. It’s hard to know how the house will be used sometimes, so we just have to make our best guesses. One interesting new item in the BC Electrical Code is a garage plug-in for an electric car!

back-framing

Back-framing: Now that the systems are getting close to done, Ron’s crew can finish the framing around ductwork and plumbing, dropping the ceiling or boxing in smaller spaces. I have also been asking for nooks and crannies and lowered ceilings and bookshelves and grab bars and towel racks, etc. The “tin-whackers,” as Ron calls the heating guys, asked for the workshop wall to be insulated and drywalled so that they could finish the big duct on that wall. I asked for plywood as a finish, so that D can screw all manner of storage solutions anywhere he wants, without having to find studs behind. I’ll also use that approach for the kitchen wall, where cupboards and tiles will hide the plywood.

insulated shop wall

So, I leave the house for 10 days. I will have withdrawal symptoms, I’m sure, but I’m getting a bit of cabin-fever, and I could use the break. Ron and the boys will look after it just fine for us. I’m grateful that I could be on site for so many of these critical decisions.