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3 Answers

Best Value Mini-Split for Cooling, Some Heating?

Climate Zone 6A, Toronto Ontario

I was at my Mom's place over the weekend and we were discussing windows and air conditioners for her small house. Her house is a small 1970's backsplit layout, about 1500 sqft including the rear basement living area, all 2x4 construction. Right now all she has is a window mounted air conditioner that she places in the master bedroom which is on the upper level a the rear of the house. It does a poor job of cooling the house but does give her relief at night for sleeping.

Asked By Lance Peters | May 26 18
1 Answer

Attached garage ventilation

I am looking for some guidance for venting an attached garage of exhaust fumes when coming and going. I have AirCycler's Garage Vent module. Now, all I need is to pair it with a fan of some sort. The garage is roughly 24x24x10. Any recommendations on brand, CFM, location?

I am considering a simple Broan through the wall exhaust fan that will do around 300 CFM at 6 sones, but that is designed for interior use. While the garage is protected from the elements, there are the issues of temperature, humidity and critters.


Asked By Norman Bunn | May 26 18
2 Answers

Mitsubishi hyperheat multi-splits and modulation

I'm thinking about having an MXZ-4C36NAHZ installed. The indoor units would be one (1) MVZ-A18AA7 ducted air handler and and two (2) MSZ-FH09NA wall units.

The 4C36NAHZ submittals say it can modulate down to 6,000 btu cooling and 7,200 btu heating.

I cannot find the minimum operating capacity of the MVZ-A18AA7, but the similar PVA-A18AA7 can modulate down to 7,000 btu cooling. The MSZ-FH09NA units can modulate down to 1,600 btu cooling.

Asked By Aun Safe | May 25 18
13 Answers

Difficulty finding a modulating multi-zone air-source heat pump

I need to finalize the equipment selection for my current build. My engineer along with Mitsubishi spec'd a City Multi (VRF) PUMY outdoor unit with multiple indoor units. Unfortunately, this outdoor unit does not have hyper-heat, which means that in order to meet the 99% heating requirements, it will be grossly oversized for cooling. While the compressor can operate down to low-20% of rated capacity, that is still much higher than an MXZ minimum operation for the same sized unit.

Asked By Jonathan Lawrence CZ 4A New Jersey | May 21 18
3 Answers

Ducted/concealed mini-split without supply or return plenums - straight out the wall?

I'm planning to install a "ducted"/concealed Daikin LV unit on the second story of my house. I haven't been able to find any definitive answers on plenum requirements, or lack there of.

the plan includes hanging the unit from unistrut in the hallway, observing all of the required tolerances for access and space around the unit. A sofit will then be built around the unit.

Asked By neockder | May 23 18
14 Answers

Water cooled refrigerator coils

This may seem weird, but I’m curious...

We just bought acreage in west central Florida and we’re planning our home. We plan on making everything as energy efficient as we possibly can, and I ve been researching geothermal ground loop heat pumps.

As I’m grabbing some leftovers out of the fridge, I feel hot air being blown on my feet from the condenser coils underneath. At the same time I hear the AC kick on outside. The lightbulb flickers on above my head... I’m running the AC to cool the room that is being warmed by the fridge...

Asked By LT.Son | May 19 18
2 Answers

Over my head

I'm new to this forum, so I hope this is an appropriate question. I'm at the planning stage for a gut rehab of a ~2500 sq ft home in Boston, MA (which I think is zone 5). We're going to be completely rebuilding the envelope and replacing all the systems. We will have 14kW of solar on the roof.

Asked By Bradslees | May 19 18
2 Answers

I'm not off the grid.. the grid's off me

We've had enough power outages here in the Hudson Valley that it is time to talk about unintentional "off-grid" living. To that end, I am interested in starting a discussion about the possibility of resiliency in high(re) performance homes. Some topics for conversation are:

  • What -if anything- can be run off off a battery? induction stove? ERV? Minisplit? Well pump?
  • How can a solar-power house be allowed to operate while the power is out - a grid cutoff?
  • What are other ways for a designer/homeowner to prepare for when they are unintentionally "off-grid"?
  • Asked By Ethan T ; Climate Zone 5A ; ~6000HDD | May 16 18
    4 Answers

    Frost-free hose bibb for a superinsulated house

    I can't be the first person to face this problem, but it feels like it because I can't see any product that addresses the problem. How the heck do you install a frost free hose bibb or sillcock without having a fitting inside the wall, when your wall is 21" thick? The longest one I can find is something like 16".

    Asked By Trevor Lambert | May 10 18
    6 Answers

    Just moved into new house (actually 20 years old, just new to us). It has fuel-oil baseboard heat with six zones.

    The system works well, but now that hot weather is here the furnace runs a lot to just heat the Hot Water Heater. That seems very inefficient to me. Running a 100,000 BTU/Hr. system just to heat water. Would not a well insulated electric HWH be more efficient and then the furnace could be totally off for 8 months a year?

    Asked By Richard Byrd | May 16 18
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