Making home cooler in summer by using existing heat transfer kit or HRV unit.

Forums › Home Workshop DIY › Making home cooler in summer by using existing heat transfer kit or HRV unit.

Tara12345

11 posts

Geek

#240929 3-Oct-2018 09:54

I hope this is in the right place. And yes... I did do a search but couldn't find anything that helped.

In the summer our house is stinking ugly hot! If we open the windows we get flys. I have a front screen door and screen curtains to let air in but on windless days with no airflow they don't help - we die.

We have 100sqm, 3 bedroom weather board home which is beautifully heated with a log fire in winter - transfer kit works awesome to heat our house.

At the moment we have two heating and cooling systems.

#1 - We have an HRV unit which we use most of the year but only a bit during winter months to keep the air fresh (never at night or we freeze), and don't use at all in summer except at night once the temperature has dropped because otherwise it makes the house too hot. We vent it from outside on the shady side of the house - not the roof cavity, because the air stinks. I've read lots on HRV units on here how they don't work, some do work, etc but probably isn't essential to what I'm wanting to do at the moment.

#2 A fantastic Heat Transfer kit sucking air from the lounge and putting into the 3 bedrooms. I would say this unit has a more powerful fan than the HRV because it feels more blowy.

Using one of these units I would like to adapt it to make the house cooler in summer. We had hoped that venting the HRV from the cool side of the house would put cool air into the house during summer. It didn't work. The ducting and roof space are so hot that it heats the in-coming air from outside so much that it just doesn't work to cool the air down.

We thought about using the heat transfer kit but if we use the inlet from the lounge then the lounge (which is also the hottest) doesn't get cool air. Maybe we could reconfigure it? I'm thinking that because this fan is more powerful maybe it would get air in before it got a chance to heat up?

My Thoughts:

Replace ducting on HRV with insulated ducting.

Using the Heat Transfer kit and reconfiguring

Removing the HRV filter? Would that let air flow faster and free-er and less chance to heat up before entering the house?

Buying a cooling fan and not using the HRV or transfer kit.

Buying a Heat Pump and not using the HRV or transfer kit.

I'm assuming the last two options would cost the most. Also - we are happy to climb into the roof space and change configuration for winter and summer.

Any suggestions would be really appreciated. Please ask anything.

Thanks.

Tara

wellygary

8328 posts

Uber Geek

#2100573 3-Oct-2018 10:59

You are attacking the symptons, but not the cause..

Bringing in cool air will help, but if it just gets heated up in the house you are back to square one

The first thing to ask is why is the House hot in summer?,

I'm guessing its the sun streaming in through windows?, if this is the case then either closing curtain or installing blinds might be a better way,

tdgeek

29751 posts

Uber Geek

Trusted

Lifetime subscriber

#2100580 3-Oct-2018 11:10

If you can do a back to back heatpump that is quite cheap. You can cool the house, and use the heat transfer system to spread the cooler air, exactly the opposite of your winter heating.

You mention screens, so I assume that the warm summer air can freely move into the house. I would keep it airtight, then open it up mid evening, and overnight if possible to allow ventilation and use the cooler night air

semigeek

1606 posts

Uber Geek

#2100665 3-Oct-2018 12:06

You can get a summer extension for a heat transfer kit, well you can for the Heat Trans brand. Ideally you’d install it on the cooler side of the house and connect it up to the heat transfer kit to bring in cool air.

Davy

196 posts

Master Geek

#2100814 3-Oct-2018 14:34

Our house is the same, with big north-facing french doors making things hot inside.

We have skylights as well, and I wish that they were the type that could be opened so that we could get ventilation with warm air able to leave the house through the ceiling.

Aredwood

3885 posts

Uber Geek

#2100977 3-Oct-2018 18:51

Cheapest- just point some fans to move air through the fly screens.

If you are referring to daytime cooling. You will have to block the sun. Curtains won't work, as they will just get hot and still radiate the heat inside. You need shade sails or similar for outside.

As the sun in NZ gives over 1000W per m2. So if you have say 10m2 of Windows, then add on some extra due to humidity. You could easily need a 14KW or so heatpump to tame that sun. And a fan would need to produce almost hurricane force winds to get rid of that much heat.

So blocking the sun is far cheaper. And if you get a heatpump, it will also save heaps on the running costs of the heatpump.

k1w1k1d

1527 posts

Uber Geek

#2101038 3-Oct-2018 21:01

Do you have plenty of ceiling insulation to stop heat radiating down from the super heated roof space?

Tara12345

11 posts

Geek

#2101661 4-Oct-2018 18:18

wellygary:

I'm guessing its the sun streaming in through windows?, if this is the case then either closing curtain or installing blinds might be a better way,

Yes the sun streams in our house. We spend most of summer with the curtains closed all day and windows all open behind them. It does help but we are still too hot.

Quic Broadband

Move to New Zealand's best fibre broadband service (affiliate link). Free setup code: R587125ERQ6VE. Note that to use Quic Broadband you must be comfortable with configuring your own router.

Tara12345

11 posts

Geek

#2101662 4-Oct-2018 18:20

tdgeek:

You mention screens, so I assume that the warm summer air can freely move into the house. I would keep it airtight, then open it up mid evening, and overnight if possible to allow ventilation and use the cooler night air

Yes that's what we do. I'll look into the back to back heat pumps for a cost. Thanks.

Tara12345

11 posts

Geek

#2101663 4-Oct-2018 18:21

semigeek: You can get a summer extension for a heat transfer kit, well you can for the Heat Trans brand. Ideally you’d install it on the cooler side of the house and connect it up to the heat transfer kit to bring in cool air.

We made our own summer extension kit (which is the same as what we would have bought) by bringing in the air from the cool side of the house. It works some what but is not as effective as I thought it would be.

Tara12345

11 posts

Geek

#2101664 4-Oct-2018 18:23

Aredwood: Cheapest- just point some fans to move air through the fly screens.

If you are referring to daytime cooling. You will have to block the sun. Curtains won't work, as they will just get hot and still radiate the heat inside. You need shade sails or similar for outside.

As the sun in NZ gives over 1000W per m2. So if you have say 10m2 of Windows, then add on some extra due to humidity. You could easily need a 14KW or so heatpump to tame that sun. And a fan would need to produce almost hurricane force winds to get rid of that much heat.

So blocking the sun is far cheaper. And if you get a heatpump, it will also save heaps on the running costs of the heatpump.

We already point fans at the screen doors to move the air out and try and make a through draft. It's looking like we might need to get a heat pump. Thanks

Tara12345

11 posts

Geek

#2101665 4-Oct-2018 18:24

k1w1k1d:

Do you have plenty of ceiling insulation to stop heat radiating down from the super heated roof space?

We most certainly do. We are very well insulated. Thanks.

Tara12345

11 posts

Geek

#2101667 4-Oct-2018 18:26

Thanks for all your suggestions. We have tried many things over the years. We have even hung wet tea towels infront of the fans and ice packs!!! Our whole lounge living area gets all day direct sun. We shut the curtains nearly all day in summer which makes the house so dark. Albeit definitely a bit cooler but still hot. Maybe we'll have to get a heat pump. Thanks.