Heating / Ventilation / AC
Getting Rid of An Oil Tank and Putting in a Heat Pump
When in doubt, put in picture of a fire hydrant - the thing you need in case of emergency. For some reason I am fascinated by them and I have taken photos of them in every place I have visited in the last ten years.
A condition of sale was that we remove the old oil tank from our house. This was swiftly and well done by Rick at Victoria Coal & Heat (250-385-8221). The company had a long association with the house. Most people who remove their oil tanks go to a natural gas furnace. Our rep, Mark Reid of Accutemp explained this choice is most often made because it allows existing ducting to be used. He cautioned that old ducting is not properly sized for electric heat pumps. It stresses them out. We decided not to use any gas in the house at all, plus, as we were opening the walls we could put in new ducting for an electric heat pump. We would use a separate set of ducting for the HRV. This page is best cross-referenced with the Indoor Air Quality section.
There were three brands we considered: Mitsubishi, Fujitsu and Daikin. All are well regarded. Mitsubishi is top of the line. Energy coaches Mark Grocoff and Mark Bernhardt both recommended Mitsubishi. Once we’d settled on an approach to making the house more air tight (via insulation and better windows) we explored various ways to put together a Mitsubishi HVAC plan with our supplier/system designer/installer at Accutemp . They were great at devising different options and answering our innumerable questions.
Here’s what’s going in as HVAC bundle for Fernwood: Lines set and fully insulated, strapped and hidden, all necessary ductwork to accommodate air handlers and for exhaust appliances and fresh air (3), digital remotes (2) for each indoor unit, start up and commissioning. I am making it sound simple, but we really agonized over this. We read up on systems, went to home shows, had various proposals on the table at one time or another, asked anyone we knew who had a system of the kind for advice. We got lots of help from John Ho, sustainability officer at the city, from Chandra Horth at City Green CleanHome BC (their free energy coach program is excellent), from Adam Campkin (engineer for the city of Saanich who did some early modeling for us). Adam walked me through the pros and cons of combining HVAC with an HRV (heat recovery unit) from the get go ….or waiting to buy the second element. We installed both at once (see Air Quality section) Our system consists of:
2 Zone Mitsubishi Heat Pump (installed)
Outdoor Model MXZ-4C36NAHZ-UI 17.50 SEER 12.50 EER 11.00 HSPF These numbers matter. Before purchasing your system be sure to establish that your system qualifies for rebates with BC Hydro.
Indoor Model PEAD-A18AA7 times 2 (one for upstairs one for down)
18k BTU concealed air handler placed in basement warm room
Our system ended up costing $25,000. The least expensive approach when switching from oil tank to electric heat pump is to use wall cassettes. No ductwork is required. The cassettes work great - but the aesthetics of the house design were very important to us, the walls were already open, thus we had the chance to run new ductwork and opted for it. Two indoor zones mean we can control the upstairs and the downstairs separately.
Consumer Reports gives a run down of the various systems with pros and cons. For more on Heat Pumps and FAQ’s a local HVAC company, Coastal Heatpumps has a very good summary.
Key points: Manufacturers generally offer low, mid and high-quality units. The HSPF rating (Heating Seasonal Performance Factor), Seasonal Energy Efficiency Rating (SEER) and sound rating all factor into the cost of the heat pump. The higher the score, the higher the price. Some people are concerned about the noise level of the outdoor unit - for their own sakes and that of their neighbors. These are all good things to ask about when you are meeting with representatives.
Heat Pump Prices
It is best to check prices in your area, comparison shop and get at least 3 bids. From what we hear, folks will spend between $1000 to $2,800 for a mid-quality heat pump unit, not including labor. After labor, fees and permits, costs can hit $20,000 or more, not including ducts. You can save 50% or more in heating costs so the payout will eventually come and in the meantime you are vastly decreasing your carbon footprint. Mitsubishi runs a promotion of no interest or payments for six months. Check it out. Important rebates are available for removing oil tanks and installing heat pumps.
Heat Pump Cost Comparison By Type
Air Source $4,500-$8,000
Geothermal $6,000-$20,000
Mini-split $2,000-$14,500
Hybrid $2,500-$10,000
Solar $18,000-$39,000
*Costs include labor and unit only. They do not include ductwork.
There is no such thing as too air-tight a house - just one that is not well enough ventilated.
Go to Air Quality section for details.
Engineer and Saanich sustainability officer Adam Campkin explains how an energy model is made and works
I asked Adam to explain. He kindly obliged. Our house presented a unique challenge. But in general here’s how energy modeling works: The geometry of the plans is a big deal. You build out the perimeter wall surface as a way of understanding heat loss. (Crawl spaces, bump outs and fireplaces are major culprits). You visually calculate the wall area and then add in the windows. You tell the software about the house’s orientation. Very important. Then the software calculates how big a heat system you will need given different levels of insulation. Since we were using solar panels exclusively to power the house, the model calculated the upper limit of what we could generate. For instance, if HSPF were 20 then you could get to net zero without any insulation! Things started to get more complicated once Adam took a wholistic approach - factoring in specific appliance needs, what would the requirements be if only 2 rather than 4 people occupied the house, how much would the HVAC and heat recovery system and electric lights use. Fascinating and fun stuff with many possible good solutions - including ours!
Low Tech Solutions Ought Not be Overlooked
Cider bottles and black ink to store heat. We saw this system applied to generate heat in The Integral Urban House - a book published by the Sierra Club in 1979 about an experiment in self-reliant urban homesteading that was located in Berkeley, California. The founders were Sim Van Der Ryn and Bill & Helga Olkowski. Fernwood and Berkeley have a lot in common. Paul Phillips might well have known Sim, Bill & Helga. Placed on window sills, the cider bottles absorb sunlight during the day. Shutters are closed by night and the heat captured in the bottles radiates into the room. Beautiful and simple.
Do You Need AC at the 49th Parallel?
It should not be the case but…..because of climate change the situation is changing. With the growing risk of wild fires you may need to filter indoor air. The deadly heat dome of the summer of 2021 made air-conditioning advisable. But more than air conditioning in our homes, we need to address human activity that is leading to extreme weather events and killing plants and animals.